NEW Brymen Bluetooth BM787BT Multimeter - Page 1
Forum section: electronics / testgear

author: EEVblog
author_rank: Unknown
timestamp: March 26, 2025, 11:56:14 pm
content: Cats out of the bag, Joe Smith just released an unboxing video, mine is still on the Fedex plane.Brymen are releasing a new BM787BT/788BT bluetooth version of the BM780 series.My exclusive one will be called the BM787BT. It's not the BM786BT because it will also have the LowZ mode that the BM786 didn't.This is the Bluetooth variant Brymen promised when they released the BM780 originally 5 years ago.The BM780 series back then even had the Bluetooth module pin header and a BT marker on the PCB, but I guess it took them this long to get it right.There will initially be an android app available.

author: bdunham7
author_rank: Super Contributor
timestamp: March 27, 2025, 01:37:50 am
content: Quote from: EEVblog on March 26, 2025, 11:56:14 pmOK, that's a plus. 1000V LowZ adds a few bucks.

author: EEVblog
author_rank: Unknown
timestamp: March 27, 2025, 03:22:51 am
content: Quote from: bdunham7 on March 27, 2025, 01:37:50 amYes, the price increased a bit for that.

author: joeqsmith
author_rank: Super Contributor
timestamp: March 27, 2025, 02:01:03 pm
content: Quote from: EEVblog on March 26, 2025, 11:56:14 pmThe UNI-T UT181A also only supported Andoid with their BLE interface. When writing the software for that meter, I had borrowed an old Android and bought one of those Adafruit sniffers for Wireshark to reverse engineer the protocol. This was before meeting with others who had also reverse engineered the interface.I still do not own a cell phone. Having a known working setup where I could sniff the traffic would certainly help answer some of my questions, but Brymen continues to be very responsive. With the time difference between our countries, it will take some time to sort it out.I am not aware of them planning to support any other platforms. My hope is that by working with them, they will create and release an interface specification into the public domain. This would allow the creators of some of the other applications to add support for this meter.

author: mwb1100
author_rank: Frequent Contributor
timestamp: March 27, 2025, 05:37:45 pm
content: Quote from: joeqsmith on March 27, 2025, 02:01:03 pmThe have published the specs for their "wired" data logging meters, so I'd expect (hope?) they'd do the same for this bluetooth protocol.

author: BILLPOD
author_rank: Frequent Contributor
timestamp: March 27, 2025, 06:37:25 pm
content: Quote from: joeqsmith on March 27, 2025, 02:01:03 pm

author: EEVblog
author_rank: Unknown
timestamp: March 27, 2025, 10:11:54 pm
content: Quote from: joeqsmith on March 27, 2025, 02:01:03 pmThey originally said it would be an open protocol, and they have sent it to me, but just the other day they asked me to hold off releasing it while they re-evaluate that. I can't think of any reason not to release it, people will just reverse engineer it anyway.The mentioned Androd, iOS and Windows apps, but only Android is available right now. I have that installed but can't do anything until my meter arrives.Was supposed to get it yesterday but Fedex are behind schedule, so it's saying Monday now.

author: joeqsmith
author_rank: Super Contributor
timestamp: March 27, 2025, 10:47:43 pm
content: They had asked me about the pros and cons of making it public domain. I made a case for releasing it.I told them my only concern with making it public would be if a end user could brick the meter using that interface. Overwrite the calibration for example. A better example would be if you change the password and loose it. You can't query the password unless you send the password. They plan to have a comment in the manual on how to reset the meter back to the factory settings (which includes the password).I have yet to get the meter to send data and am asking them for further clarifications. IMO, it would be a bit premature to release that document. Are you planning to write your own custom software for it?

author: EEVblog
author_rank: Unknown
timestamp: March 27, 2025, 11:59:52 pm
content: Fedex tracking now says it's on the truck for today.Should I do a live stream doing a teardown and phone connection test?

author: EEVblog
author_rank: Unknown
timestamp: March 28, 2025, 12:01:33 am
content: Quote from: joeqsmith on March 27, 2025, 10:47:43 pmNo plans if they are going to ahead with the apps for all platforms, and the protocol is released.

author: EEVblog
author_rank: Unknown
timestamp: March 28, 2025, 12:05:53 am
content: Quote from: joeqsmith on March 27, 2025, 10:47:43 pmI don't know why that password exists, maybe they have a customer application in mind.There is no mention in the protocol of being able to send calibration data, so seems impossible to goof up the meter.

author: joeqsmith
author_rank: Super Contributor
timestamp: March 28, 2025, 01:45:07 am
content: Quote from: EEVblog on March 28, 2025, 12:05:53 amNote that the specification I have states "to be continued". It's obviously a preliminary spec. Working with the BLE interface, the meter reports undocumented handles. These UUIDs are similar to the ones mentioned in the specification.

author: EEVblog
author_rank: Unknown
timestamp: March 28, 2025, 03:39:44 am
content: I have to leave in 10min and no sign of the Fedex truck. Guaranteed not to turn up this week now. No ability to mark as leave without signature.

author: EEVblog
author_rank: Unknown
timestamp: March 28, 2025, 08:46:32 am
content: Fedex guy left it!

author: u666sa
author_rank: Frequent Contributor
timestamp: March 28, 2025, 10:17:20 am
content: Bleh. I have a UNI-T UT61E+ here. It is also Bluetooth capable. However, that is a stretch to say it like that. When I ordered Bluetooth dongle I found out that there is no software for windows, there is software only for iPhone. Since I wanted to display multimeter information in OBS, it's as good as it don't have any Bluetooth.Unless of course me want to write my own software for Windows.

author: tautech
author_rank: Super Contributor
timestamp: March 28, 2025, 10:23:06 am
content: Quote from: u666sa on March 28, 2025, 10:17:20 amYet both of the mini PC's here, running Windoze 10&11 are Bluetooth capable.Some new toys demand new PC HW......

author: joeqsmith
author_rank: Super Contributor
timestamp: March 28, 2025, 10:52:52 am
content: Quote from: tautech on March 28, 2025, 10:23:06 amWhile Windows has supported BLE for years, this does not suggest UNI-T wrote software for that platform.I ran into the same problem with the BLE adapter for their UT-181A. They advertised having software for Windows but when the adapter arrived, they had nothing. The only way to get it running was to write my own Windows application. This is NOT a HW problem as suggested. It's a lack of software.Quote from: EEVblog on March 28, 2025, 08:46:32 amWhen/where is the live stream?You should have an updated manual today. This answered some of my questions but I am still unable to get the meter to respond correctly.

author: u666sa
author_rank: Frequent Contributor
timestamp: March 28, 2025, 11:30:36 am
content: Quote from: tautech on March 28, 2025, 10:23:06 amThat's not my point, but niet. Both of your PCs are not proper bluetooth capable. You need a special adapter in most cases, with programmer (or you stuck with manufacturer's adapter). But buying an adapter with programmer is cheaper and more flexible solution!!It's called Zigbee CC2540 (not CC2531). After it arrives, you flash it with correct firmware and your multimeter will connect properly to windows. Essentially adapters that manufacturers sell is this thing, programmed, and wrapped in plastics.https://ibb.co/wFg4ch0bQuote from: joeqsmith on March 28, 2025, 10:52:52 amIs it availble for public download? Could you provide link to your software? Perhaps source code?

author: u666sa
author_rank: Frequent Contributor
timestamp: March 28, 2025, 11:37:27 am
content: I have some time to kill at this point and can program. I might as well write an app in FireMonkey for Windows, Linux and Mac.

author: mwb1100
author_rank: Frequent Contributor
timestamp: March 28, 2025, 05:13:53 pm
content: Oneveryminor note on a difference between Dave's BM787BT and Joe's BM788BT:- Dave's BM787BT case is from a BM789 with tape obscuring missing functions or adding the missing bits and nameplate- Joe's BM788BT case is unmodified - it's very much like a BM789's case, but there's no tape obscuring the dBm mode marking or tape used for the meter's nameplateLike I said - a minor thing. Brymen is farther along with the BM788BT (as one would expect) or maybe they had some BM788BT cases lying around from the abandoned/stalled effort 5 years ago.It looks like the BM787BT is a BM786 with bluetooth and nothing else added. The BM788BT is BM789 with bluetooth added and dBm support removed (maybe also without the 100kHz bandwidth?)

author: danno_cj
author_rank: Contributor
timestamp: March 28, 2025, 05:19:47 pm
content: BM787BT got LoZ, this feature is missing on BM786.

author: bdunham7
author_rank: Super Contributor
timestamp: March 28, 2025, 05:34:25 pm
content: Quote from: mwb1100 on March 28, 2025, 05:13:53 pmI think there's too much market micro-segmentation here--there's now 5 different meters (785, 786, 787BT, 788BT, 789) based on one common design and with one feature added or deleted here and there. Does it really change the cost to add or delete the dBm or 4-20mA loop features? Perhaps there is a good reason for some of this, namely allowing for an EEVBlog version without violating current agreements with other distributors. But why have a 788BT with just a few minor features deleted from the 789? Anyway, the 787BT looks like it has a good set of core features now that they've added LowZ. I hope the price is competitive.BT is very handy for household electrical work because it allows you to put the meter one place while you go operate something elsewhere and get a reading on your phone. I'm not as enthusiastic about using this as a logging method, but we'll see how that shakes out. Let's see if Dave and Joe can actually get their respective samples working correctly...

author: joeqsmith
author_rank: Super Contributor
timestamp: March 28, 2025, 05:53:36 pm
content: I would have thought having a different colored boot with a different part number and selling the 789 would have been cheaper than the engineering and documentation to have this different models.Quote from: bdunham7 on March 28, 2025, 05:34:25 pmI had asked why they dropped support for dBm with the BM788BT. Apparently they ran out of code space when adding the BLE option.Quote from: bdunham7 on March 28, 2025, 05:34:25 pmBrymen have been working at answering my questions about the BLE interface. As I mentioned, they provided an update to the standard today. If Dave stays with the provided software, I expect it will just work. I'm a ways off from being able to do any sort of testing with it.

author: mwb1100
author_rank: Frequent Contributor
timestamp: March 28, 2025, 08:01:25 pm
content: Quote from: bdunham7 on March 28, 2025, 05:34:25 pmMy recollection is that this was exactly why the 786. Don't know why that wasn't needed for the BM235.

author: EEVblog
author_rank: Unknown
timestamp: March 28, 2025, 09:59:58 pm
content: Quote from: u666sa on March 28, 2025, 10:17:20 amIt's all about the software. Bryemn just said that Android and iOS will be available upon release, with Windows a few months later.I'd show you a screen shot, but I just get the message "Pairing rejected by BM78xBT"

author: EEVblog
author_rank: Unknown
timestamp: March 28, 2025, 10:07:25 pm
content: Quote from: bdunham7 on March 28, 2025, 05:34:25 pmCorrect. Brymen are super loyal to distributors. I wanted to sell the BM869 and BM257 back in the day, but they already had an agreement with CABAC here in Australia. Try buying a Brymen meter from CABAC, LOL.I only got the BM235 because I got wind of it a year before release and CABAC didn't know or didn't care about it.

author: EEVblog
author_rank: Unknown
timestamp: March 28, 2025, 10:10:16 pm
content: Quote from: danno_cj on March 28, 2025, 05:19:47 pmYes. It originally didn't have the LowZ and was going to be called the BM786BT, but I asked for the LowZ to be added, so they changed the number to the BM787BT.

author: joeqsmith
author_rank: Super Contributor
timestamp: March 29, 2025, 12:03:17 am
content: QuoteQuote from: EEVblog on March 28, 2025, 09:59:58 pmhaving never owned a cell phone, do you even need any software to pair it? I was able to pair to it with the PC (shown in that short video). The microsoft BLE tools talk to it to some extent. My custom test program will sniff the meter's advertisements. That comes back correctly per the manual. I can pair to it, and download the meter's handles. The UUIDs all match with the new manual. From there I can read the meter's ID. The problem is you can't do anything until you send the password. I have provided Brymen with details on what I send to the meter (part of the reason for the manual updates). I believe we now have the CRC sorted. But the meter always responds with the same error. The error code is not listed in the spec. It seems pretty straight forward, but if you are having problems getting their software to work I wonder if something else is going on outside of my software.Oh well, I'm sure we can sort it all out in time.

author: EEVblog
author_rank: Unknown
timestamp: March 29, 2025, 12:22:12 am
content: Quote from: joeqsmith on March 29, 2025, 12:03:17 amThe Android OS does the pairing, just how you pair to any other bluetooth device like headphones etc.The meter shows up under new devices but it will not pair.

author: floobydust
author_rank: Super Contributor
timestamp: March 29, 2025, 12:45:03 am
content: What batteries does this use? Generally a PITA with Bluetooth is the higher power consumption if it's streaming.How much (logging) memory does it have? I'm wondering if you could use it to log a few day's data, then use BT to retrieve that log, to save power.

author: joeqsmith
author_rank: Super Contributor
timestamp: March 29, 2025, 01:47:20 am
content: Quote from: EEVblog on March 29, 2025, 12:22:12 amReally odd. I have been able to pair using that old tablet (latest Windows 10) and my desktop PC (old Win 10) using a Targus and another BLE adapter.We just tried to use my wife's iPhone. It does not list the BM788BT or the two radios in my desktop PC. Both radios are able to see the iPhone and pair with it. Her iPhone does see her watch and car just fine.

author: EEVblog
author_rank: Unknown
timestamp: March 29, 2025, 02:33:38 am
content: Quote from: floobydust on March 29, 2025, 12:45:03 amThree AAA, same as the BM780 series. It is not a "new" meter as such, it's the exact same hardware as the BM780 series, but with the bluetooth module soldered in

author: EEVblog
author_rank: Unknown
timestamp: March 29, 2025, 05:11:55 am
content: Teardown photos:https://www.flickr.com/photos/eevblog/albums/72177720324728017

author: mwb1100
author_rank: Frequent Contributor
timestamp: March 29, 2025, 05:36:21 am
content: Quote from: joeqsmith on March 28, 2025, 05:53:36 pmSo there's a good chance they planned on a BM789BT but had to punt on that because of the ROM space. That probably made for some very unhappy people at Brymen.

author: EEVblog
author_rank: Unknown
timestamp: March 29, 2025, 05:42:54 am
content: Live teardown for those interested:

author: joeqsmith
author_rank: Super Contributor
timestamp: March 29, 2025, 10:24:14 am
content: The four pin header on the BT module had an unpopulated pin. Note the new PCB has only 3 holes where the older one was 4.In 2019, they did not list the BT option but note how it used 2X4 pin headers. You mentioned in your video how you voiced your concerns to Brymen about potential problems screwing up their meter when using the Bluetooth:https://youtu.be/TkmMitYnHUA?t=2208I am curious what their response was and if you mentioned to them my comment to you about the undocumented handles?

author: Aldo22
author_rank: Super Contributor
timestamp: March 29, 2025, 12:13:42 pm
content: Quote from: floobydust on March 29, 2025, 12:45:03 amThat's a good thing.My Owon CM2100B does that. They call it: “Offline Recording Function”.It can record 10000 measurements.How long this takes depends on the selected interval.With an interval of 30s, it records approx. 83 hours.This could be similar with the Brymen.

author: Nuts and Proud
author_rank: Newbie
timestamp: March 29, 2025, 12:14:41 pm
content: Dave, will this meter work on Linux? This will be a deal breaker for me and many others.

author: joeqsmith
author_rank: Super Contributor
timestamp: March 29, 2025, 07:21:33 pm
content: Quote from: u666sa on March 28, 2025, 11:30:36 amHere you will find others posted an interface document and someone was creating an open sourced program for it. I have not released mine.https://www.eevblog.com/forum/projects/uni-t-ut-d07a-bluetooth/

author: joeqsmith
author_rank: Super Contributor
timestamp: March 29, 2025, 07:27:49 pm
content: Brymen did ask me about running a few more tests. Sadly, none of that worked out. I have asked them about the cell phone requirements to run their application. If I had a working setup, I still have the Adafruit BLE sniffer that works with Wireshark. Because Dave's Rev 15 Android doesn't pair, I think I'll hold off. Going from 0 cell phones to having 10 different ones laying around for testing..... this is how I end up with so many scopes, meters, VNAs.....

author: floobydust
author_rank: Super Contributor
timestamp: March 29, 2025, 07:38:00 pm
content: I see the Infineon (Cypress)CYBLE-212006-01Bluetooth 4.2 module.2-3.6V and 90mA TX full power, 17mA TX quiescent, 8mA RX quiescent, 256KB FLASH 32KB SRAM. MCU 48MHz. Thing is expensive $10 but includes the BT stack, it's been around since 2017.They are likely using the platform stock firmware in the module.I would look at serial debug info on the comm header to troubleshoot. I don't think the DMM LCD has much to offer for that as far as displaying connection error messages.The 3-pin header J10U is just battery power to the BT board LDO. Two pins +, and one or two pins for GND.

author: joeqsmith
author_rank: Super Contributor
timestamp: March 29, 2025, 07:50:59 pm
content: That is what I ended up doing with Dave's 121GW to sort things out. Hoping we don't have to go to this level with the Brymen.

author: bdunham7
author_rank: Super Contributor
timestamp: March 29, 2025, 11:00:14 pm
content: Quote from: joeqsmith on March 29, 2025, 07:27:49 pmPost your address so we can all mail our old phones to you....

author: bdunham7
author_rank: Super Contributor
timestamp: March 29, 2025, 11:31:09 pm
content: Quote from: floobydust on March 29, 2025, 07:38:00 pmThat's the sort of thing I was concerned about--turning it into a battery-eating monster and then having AAA batteries to boot. My Fluke IR-BT interface does this, using 2x AAA when there would be plenty of room for AA or even 2x 18650. Battery life is terrible (like 5-6 hours!) and I don't think it is because of the IR part.

author: EEVblog
author_rank: Unknown
timestamp: March 30, 2025, 05:04:44 am
content: Quote from: Nuts and Proud on March 29, 2025, 12:14:41 pmThey have not mentioned linux. But if the drivers are open source then someone will do it, probaby under Sigrok.Even if they don't release it, someone will reverse engineer it.

author: joeqsmith
author_rank: Super Contributor
timestamp: March 30, 2025, 03:44:44 pm
content: Quote from: bdunham7 on March 29, 2025, 11:00:14 pmSound like Dave would make better use of them.I did try sending incremental data to the meter in an attempt to find out what is causing the error. I noticed if I don't throttle the communications, the meter will stop sending data. The BT indicator remains active. If I close the connection and sniff, the meter is will no longer advertise. I have to toggle the BT button to get it to clear. Still, no luck getting beyond the password.

author: joeqsmith
author_rank: Super Contributor
timestamp: March 31, 2025, 03:34:28 pm
content: Brymen reminded me today about their use of the large MTU size. Of course, that is clearly stated in the spec.I had not thought about it since Gossen, UNI-T and Kean all stayed within the 20 Byte limit. Time to order up a new radio.

author: EEVblog
author_rank: Unknown
timestamp: March 31, 2025, 11:39:07 pm
content: Just put the BM787BT back together (twice), and, umm, it doesn't switch on...

author: EEVblog
author_rank: Unknown
timestamp: April 01, 2025, 01:47:53 am
content: Got the app app working, it DOESN'T need to be paired first!

author: mwb1100
author_rank: Frequent Contributor
timestamp: April 01, 2025, 02:27:40 am
content: I think your comments about the shortcomings are on point. The real time logger should have a button on that main widget on the bottom of the screen. You can tell that Brymen doesn't do software!Their software for logging on their meters that support a serial/USB connection is really clunky - particularly the setup. There are also at least a few small bugs (for example, I have to hand edit the CSV files to get Excel to read them in). One of the worst things is that each multimeter model (or "family") needs its own completely separate software install. You'd think they'd have one software module that handles the UI and capture of the data and several driver modules that handle the particulars of the communication. Kind of like sigrok orHKJ's Test ControllerBrymen's software has the feel that the project was given to a Summer intern and once they got something that mostly works, that was it.That is one of the reasons they should publish the spec - it'll get better software for the meters out there sooner. And that'll surely sell more meters.

author: DaneLaw
author_rank: Frequent Contributor
timestamp: April 01, 2025, 11:20:25 pm
content: The update rate atleast seems pretty good..around 4 times per second and some of the fatest I have seen from any handheld DMM apphttps://youtu.be/ruxzp0OMicg?si=WW2BWT03plnD2m4_&t=265Way faster than what I'm getting on this old Owon model from 2015 and its app that seems to peak at around 2 times pr second, which is like a decade old app (BT BLE 4.0 protocol) been a half-baked solution from day one, recall problems with autoaligning its graph, so it was stacking/cramping or in roll mode.Its a DMM to 35 to 40$ meters, and was a cheap way back then to "datalog" alongside having the ability for vocal readout (in your own language) so you didn't have to look at the screen.Could be quite useful in certain situations, not least with these timed display-light, that could be quite annoying to work around.

author: JoeyG
author_rank: Regular Contributor
timestamp: April 02, 2025, 12:07:54 am
content: Wifi module data sheet is herehttps://fccid.io/WAP2006/User-Manual/User-Manual-3115390.pdfBLE 4.2

author: Black Phoenix
author_rank: Super Contributor
timestamp: April 02, 2025, 11:06:23 am
content: Very interesting Dave, really.Probably I will think about getting one in the future just as my first non Fluke,

author: Refrigerator
author_rank: Super Contributor
timestamp: April 02, 2025, 12:36:12 pm
content: I saw the video with the brymen app and it seems fine as a proof of concept, but horrendous from a usability standpoint.Here's my vision of what i would expect:1. Names for DMM's, because why not, it makes it easier to tell them apart from your list of devices. If i can name my cheap chinese BMS, then why can't i name my expensive DMM right? EE's tend to have multiple so it would make sense to have names for them.2. "devices" tab where you add, remove or inspect devices. Tapping on a device should mirror the devices display on your phone.3. Window based workspaces tab, where you can arrange measurements from one or more devices. I've got this idea from a car app, namely "Torque", that allows me to drag, drop and resize displays and graphs that show my engine parameters etc. and i really like the concept. I think it would be really neat if you could do the same with multiple DMM's. I think it would be best if you could save multiple of these workspaces for different setups.4. "Data logger", where you could set up data logging. Would be neat if this data logging was rule-based (or script based).For exampleCode:"start logging: time: =12:34" and then "data: DMM1: voltage, data: time, data: DMM2: current".Or something similar, you get the idea...I got this idea from the Steelseries GG app for my peripherals. The GG app is quite modular when setting up macros and rules and this modularity allows me to do some very basic scripting. It showed me a concept that i really liked and would like to see with this brymen app also.5. Math functionality, where you could, for example, do power calculations from two different DMM's simultaneously. Kind of like you do in LTspice.

author: Refrigerator
author_rank: Super Contributor
timestamp: April 02, 2025, 01:44:31 pm
content: I actually wanted to make my own bluetooth connected DMM, because i found what i thought was a perfect cheap DMM to do the job.What i found was a Parkside DMM at LIDL, that had a 6000 count autoranging IC in it with a serial UART output, but when i pulled apart the DMM to probe the TX pin i found out that it's permanently pulled low and i couldn't find any way to re-enable any communications. The IC has OTP memory so it's not possible to reprogram anything in it.I was already planning on what BLE device to stick inside to transmit the data wirelessly over bluetooth to my devices before i found out that there's no comms, so it sure spoiled the fun

author: joeqsmith
author_rank: Super Contributor
timestamp: April 02, 2025, 04:01:27 pm
content: Quote from: EEVblog on April 01, 2025, 01:47:53 amI handle the scanning and pairing in my software as well. The only thing I have to do from Windows is have Bluetooth turned on. When I showed the pairing in that first video with the tablet, I had no software to support it. My wife's software for her car is like that as well.

author: SHF
author_rank: Regular Contributor
timestamp: April 03, 2025, 12:07:53 pm
content: Is the BM787BT also available in blue?

author: EEVblog
author_rank: Unknown
timestamp: April 03, 2025, 12:09:36 pm
content: Quote from: SHF on April 03, 2025, 12:07:53 pmYes, it will be, they just rushed this one to me to test.

author: joeqsmith
author_rank: Super Contributor
timestamp: April 06, 2025, 01:59:47 am
content: Have you measured the battery life? Now that you have their phone application talking to the meter, how does the battery voltage effect the Bluetooth reliability?

author: zoza81
author_rank: Newbie
timestamp: April 08, 2025, 07:01:13 am
content: Has there been any mention of $$ or release date?Deciding on whether I should order the BM786 or wait for this model.

author: EEVblog
author_rank: Unknown
timestamp: April 08, 2025, 07:40:36 am
content: Brymen have decided to release the bluetooth protocol, here it is:https://eevblog.com/files/BM780-Wireless-Communication-Protocol-r2.pdf

author: EEVblog
author_rank: Unknown
timestamp: April 08, 2025, 07:44:38 am
content: Quote from: zoza81 on April 08, 2025, 07:01:13 amEnd of May for the initial production batch, with regular market shipments by July.Not sure if I can get stock from the first lot.I haven't decided on exact price yet, but expect at least US$30 more than the BM786.

author: zoza81
author_rank: Newbie
timestamp: April 08, 2025, 08:41:03 am
content: Thanks Dave - that puts it at about $50 aussie bucks (or more by July).Eh, I don't really have a need for BT logging and LoZ is a nice to have - 786 it is then.

author: EEVblog
author_rank: Unknown
timestamp: April 08, 2025, 09:42:19 am
content: Just heard I'm getting my first batch early June.

author: webspiderteam
author_rank: Newbie
timestamp: April 11, 2025, 07:06:25 pm
content: Thanks for sharing this Data ProtocolI just finished to decode Uni-T devices bluetooth protocol for my app I want to add this Dmm for pc users.

author: EEVblog
author_rank: Unknown
timestamp: April 17, 2025, 05:22:18 am
content: I logged data for an hour and half using a 1k resistor and only got 2 data dropouts with the phone half way across the lab sitting on top of my computer.Annoyingly the data in the CSV has the units on the end, you have the strip that before using the cell data. Dumb when they have the units in the cell next to it.Apart from that it didn't drift beyond 1.0000 or 0.9999

author: webspiderteam
author_rank: Newbie
timestamp: April 17, 2025, 03:33:22 pm
content: Is there any raw data log? I need to test if decoding works correctly...

author: joeqsmith
author_rank: Super Contributor
timestamp: April 17, 2025, 03:54:11 pm
content: Quote from: webspiderteam on April 17, 2025, 03:33:22 pmWhat exactly would you like?

author: webspiderteam
author_rank: Newbie
timestamp: April 17, 2025, 06:24:01 pm
content: Just raw data that came from bluetooth. Something like "AA BB CC DD EE FF 11 12 13" e.g. in dataprotocol it says 185 Bytes bytes but basically its Device Information Packet (24 bytes) + Device Reading Packet(32 bytes). I need these datas to test

author: joeqsmith
author_rank: Super Contributor
timestamp: April 17, 2025, 06:39:26 pm
content: Quote from: webspiderteam on April 17, 2025, 06:24:01 pmWhen you wrote raw, I was assuming Wireshark. So you only want the 152 byte Information/Reading packets from the meter.How do you want them saved? What format? ASCII? Binary?What are you proposing as far as running the meter during this collection? One mode only wouldn't do much for your decode test. Think about what exactly you would like, and I am sure I could create it for you.***Maybe start with the meter with the switch in ACV mode, then cycle through all the settings before selecting the next function. Maybe wait 5-10 seconds between selections. Maybe save it all in binary. Maybe nothing attached to the meter to make it simple. Some functions like resistance would read an open.Not so simple as just, some raw data.

author: webspiderteam
author_rank: Newbie
timestamp: April 17, 2025, 06:51:26 pm
content: ascii is good for meBTW I don't have that device. I just saw that there is no windows app for it.I already have a application for bluetooth multimeters that shows display on windows desktop. I saw your video about Brymen multimeter and I decided to add this multimeter too. If you wanna look my app is on github.https://github.com/webspiderteam/Bluetooth-DMM-For-Windows

author: joeqsmith
author_rank: Super Contributor
timestamp: April 17, 2025, 07:27:25 pm
content: Quote from: webspiderteam on April 17, 2025, 06:51:26 pmOk, ASCII it is, I'll leave the hyphens in as well. You you want one line per packet? Don't care? Anything special for EOL? EOF?Again, how do you want the meter exorcised? Don't care?

author: webspiderteam
author_rank: Newbie
timestamp: April 17, 2025, 07:35:51 pm
content: One line per packet is better. More understandablethanks alotIt doesnt metter I just need to test data if they are decoded correctly. If data has different mode of multimeter this can make decoding more accurate.

author: joeqsmith
author_rank: Super Contributor
timestamp: April 17, 2025, 08:21:34 pm
content: Quote from: webspiderteam on April 17, 2025, 07:35:51 pmBut your decoding could be totally wrong and you would have no way of knowing. This is why I was suggesting some known test pattern. One way would be to record the packets and at the same time record a video of the meter running. You could use the meter's time stamp and synchronize the two. At least this way you have some idea if what you are showing matches with the meter.Does seem like the value would need to change as well so you can test out that part of the decode as well.Modding my code, collecting and posting some data, simple. Figuring out what you want, not so simple.If the video makes sense to you, I will run it tonight.

author: webspiderteam
author_rank: Newbie
timestamp: April 17, 2025, 09:18:45 pm
content: Basically I need something like thatUUID:49535343-1e4d-4bd9-ba61-23c647249616 {171, 205, 4, 255, 0, 2, 123}09.04.2025 21:23:56UUID:49535343-1e4d-4bd9-ba61-23c647249616 {171, 205, 4, 255, 0, 2, 123}09.04.2025 21:23:56UUID:49535343-1e4d-4bd9-ba61-23c647249616 {171, 205, 8, 85, 84, 54, 49, 69, 43, 3, 0}09.04.2025 21:23:56UUID:49535343-1e4d-4bd9-ba61-23c647249616 {171, 205, 16, 2, 48, 32, 48, 46, 48, 48, 50, 51, 0, 7, 48, 48, 48, 3, 148}09.04.2025 21:23:58UUID:49535343-1e4d-4bd9-ba61-23c647249616 {171, 205, 16, 2, 48, 45, 48, 46, 48, 48, 49, 51, 0, 7, 48, 48, 49, 3, 161}09.04.2025 21:23:59UUID:49535343-1e4d-4bd9-ba61-23c647249616 {171, 205, 16, 2, 48, 45, 48, 46, 48, 48, 48, 48, 0, 4, 48, 48, 48, 3, 153}09.04.2025 21:23:59UUID:49535343-1e4d-4bd9-ba61-23c647249616 {171, 205, 16, 2, 48, 45, 48, 46, 48, 48, 48, 48, 0, 4, 48, 48, 48, 3, 153}09.04.2025 21:23:59UUID:49535343-1e4d-4bd9-ba61-23c647249616 {171, 205, 16, 2, 48, 45, 48, 46, 48, 48, 52, 53, 0, 4, 48, 48, 49, 3, 163}09.04.2025 21:24:00UUID:49535343-1e4d-4bd9-ba61-23c647249616 {171, 205, 16, 2, 48, 45, 48, 46, 48, 48, 48, 48, 0, 5, 48, 48, 48, 3, 154}09.04.2025 21:24:00UUID:49535343-1e4d-4bd9-ba61-23c647249616 {171, 205, 16, 2, 48, 32, 48, 46, 48, 48, 49, 48, 0, 4, 48, 48, 49, 3, 142}09.04.2025 21:24:00UUID:49535343-1e4d-4bd9-ba61-23c647249616 {171, 205, 16, 2, 48, 32, 48, 46, 48, 48, 50, 56, 0, 5, 48, 48, 49, 3, 152}09.04.2025 21:24:00UUID:49535343-1e4d-4bd9-ba61-23c647249616 {171, 205, 16, 2, 48, 45, 48, 46, 48, 48, 52, 49, 0, 6, 48, 48, 48, 3, 160}09.04.2025 21:24:01UUID:49535343-1e4d-4bd9-ba61-23c647249616 {171, 205, 16, 2, 48, 32, 48, 46, 48, 48, 50, 48, 0, 6, 48, 48, 49, 3, 145}09.04.2025 21:24:01but UUID not that important for now. I will use it as emulated input for program then I will test my results. also I have an gatt server emulator that I can send data packages to phone to mach the results.

author: joeqsmith
author_rank: Super Contributor
timestamp: April 17, 2025, 11:08:11 pm
content: This is why I asked you to provided EXACTLY what you wanted from the start not several posts into the discussion. If you can use the format and data I have provided in the attached example, I will collect more data for you.

author: bdunham7
author_rank: Super Contributor
timestamp: April 18, 2025, 01:39:35 am
content: Quote from: EEVblog on April 17, 2025, 05:22:18 amWhy does it go to 10.000 when the "dropout" happens?

author: EEVblog
author_rank: Unknown
timestamp: April 18, 2025, 03:41:46 am
content: Quote from: bdunham7 on April 18, 2025, 01:39:35 amI have no idea, I didn't expect that. Could be a quirk in the app when it gets a dropped packet?Both samples are 9.9996k actually. Well outside the 60,000 count range of the ADC. I don't think it can autorange for one sample and then autorange back the next sample, so it has to be a quick in the app/received bluetooth data

author: EEVblog
author_rank: Unknown
timestamp: April 18, 2025, 04:44:24 am
content: 2nd test for 1 hour, phone less than 10cm away from the meter. I received and made a call around the 55min mark.Not a single digit change, all values are 1.0000kThe last sample drop is just an empty cell

author: EEVblog
author_rank: Unknown
timestamp: April 18, 2025, 08:10:02 am
content: Another test , this time across the lab as far as I could go, about 9 meters.4 "dropouts" of again 9.9996kAnd again, within one count on every other 1k sample.So seems to be distance related dropout of some description, as you'd expect, but they need to handle the data better by logging NULL or something instead of a false reading.

author: floobydust
author_rank: Super Contributor
timestamp: April 19, 2025, 07:25:00 pm
content: I'm thinking there are three firmware loads in this multimeter?The DMM MCU, the Bluetooth module base (libraries), the Bluetooth module app. The module base F/W I think is old and hopefully stable but it might have fallen in the cracks with Infineon's acquisition of Cypress. Developers get sacked and an ecosystem just sits there orphaned.edit: as far as black box testing goes, I suggest trying some things such as a different function or sample rate or noisy BT environment etc. to flush out what is happening.

author: EEVblog
author_rank: Unknown
timestamp: April 22, 2025, 12:15:42 am
content: Brymen said they will remove the units from the CSV value column

author: joeqsmith
author_rank: Super Contributor
timestamp: May 06, 2025, 05:50:49 pm
content: Quote from: EEVblog on April 08, 2025, 09:42:19 amHave you heard if they are going to push this date out? If the 10X problem is with the radio's firmware, I wonder how distributors will handle the upgrades. I have to believe they will have these basic problems solved ahead of time.

author: EEVblog
author_rank: Unknown
timestamp: May 06, 2025, 10:18:09 pm
content: Quote from: joeqsmith on May 06, 2025, 05:50:49 pmI haven't heard yet.It's common for Brymen to delay a release though, so it wouldn't surprise me.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 06, 2025, 11:00:16 pm
content: Quote from: EEVblog on May 06, 2025, 10:18:09 pmLooks like their radio had the programming connector attached. I ordered the programmer for it and have asked it Brymen will provide details and programming files for it. There may be a way around having to use the phone to upgrade the radio.

author: EEVblog
author_rank: Unknown
timestamp: May 06, 2025, 11:20:18 pm
content: Quote from: joeqsmith on May 06, 2025, 11:00:16 pmI'm sure there is. But that's not a solution for users. Just like upgrading the meter firmware is possible but not an option for users.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 06, 2025, 11:43:12 pm
content: Quote from: EEVblog on May 06, 2025, 11:20:18 pmSorry, you lost me. The goal is to replicate the 10X glitch you are seeing, and understand why my phone will not connect with the meter. While they are working on these problems, I am attempting to get a parallel path going.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 07, 2025, 12:21:10 am
content: The more I read about the radio they chose, the more I would lean towards including details about programming it in their manual. They are using a bootloader with fallback. Chances of bricking it should be slim.

author: EEVblog
author_rank: Unknown
timestamp: May 07, 2025, 07:53:35 am
content: Quote from: joeqsmith on May 06, 2025, 11:43:12 pmoh, ok, my mistake.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 10, 2025, 07:38:58 pm
content: No problem. I started a new thread on the eval boards for their radio.https://www.eevblog.com/forum/projects/cypress-psoc-creator-miniprog3-ez-bleI have been doing a lot of reading about how the programming works and started to write my own. I've made some progress but so far, that has been a bust.They are setting me up with a Beta for the iPhone which I hope to have working next week. With any luck, this will allow me to update the radio's firmware. They should also have that BLU phone like mine to start testing with. Lots of irons in the fire..

author: joeqsmith
author_rank: Super Contributor
timestamp: May 12, 2025, 12:11:51 pm
content: I was able to get the iPhone application setup. It connects to the meter as fast as my custom Windows application.When attempting to update the meter's radio, I get the same "Not Network". I tried to then manually select the firmware file. They never prompt for a filename, and I once again see some Chinese text displayed. Apparently they have tested several versions of the iPhone and my wife's happens to be problematic list. For now, we just have to wait.The meter, and even the radio as far as I can tell, have been working perfect since arriving.

author: EEVblog
author_rank: Unknown
timestamp: May 13, 2025, 09:25:48 am
content: Brymen response on the data dropout issue:Quote

author: joeqsmith
author_rank: Super Contributor
timestamp: May 13, 2025, 10:20:05 am
content: They mentioned that earlier. Because I have been unable to reproduce the 10X problem you saw, I would have no way to test anything they came up with.A few thoughts about it. They use a large enough MTU that the entire payload fits into one packet. Bluetooth has built in error handling, so I couldn't see how this was going to be a problem. Let's say it is the cause. The first step to talk to the meter is send the password command. When I first attempted to talk with the meter, they had not yet provided details about the CRC. Guessing at the format proved a waste of time as the meter uses that CRC. In other words, the group responsible for the software would have had the CRC coded and working for anything else to work. So why they wouldn't check the CRC, length, header and footer as a minimum seems a bit odd?My question, which YOU are the ONLY one who can answer (as Brymen has also been unable to replicate), does this new version correct the 10X problem?

author: floobydust
author_rank: Super Contributor
timestamp: May 13, 2025, 05:07:29 pm
content: They still don't say what it does with a bad CRC, now that it notices this.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 13, 2025, 05:58:54 pm
content: With my app, I keep a metric but bundle CRC with all the others. If I ever did detect a fault, I still process the data. I would expect my software to be every bit as bad as theirs in that regard. With all of my testing, I don't believe it has ever detected a fault which makes sense.https://www.bluetooth.com/wp-content/uploads/2019/03/Bluetooth_5-FINAL.pdfDave needs to test it and report back.

author: floobydust
author_rank: Super Contributor
timestamp: May 13, 2025, 06:39:57 pm
content: I find it weird the exponent gets consistently corrupted to x10 for Dave, despite any random bunch of bits that could have gotten scrambled in the packet. That points to it being a side-effect bug, where a variable next door is wrongly being overwritten or maybe it's that  or  digit thing getting trashed.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 13, 2025, 08:23:48 pm
content: I find it somewhat weird that I was not able to replicate the problem, using the same DMM firmware and Android application. It makes no sense that the radio's firmware would be the cause but it is certainly a difference. As is the phone make/model. When Brymen told me that they were also unable to replicate it, that's the real head scratch er. Still, I doubt they have Dave's exact same phone.I was hoping Dave knew Wireshark and could just sniff the packets. At least it would have answered if the problem with with the meter or the phone. Engineering 101, cut the problem in half.My plan is to stay with the old application until I am able to update the radio. I will then try once again to replicate the problem.

author: EEVblog
author_rank: Unknown
timestamp: May 14, 2025, 01:56:31 am
content: Quote from: joeqsmith on May 13, 2025, 08:23:48 pmHow does WireShark, which is network sniffing program for Windows, help debug a 1-in-1000 data corruption issue on an Android phone?

author: joeqsmith
author_rank: Super Contributor
timestamp: May 14, 2025, 03:35:31 am
content: Quote from: EEVblog on May 14, 2025, 01:56:31 amBlueTooth is a network. Wireshark will collect the data, filter, save, etc. You can target the meter, ignoring all other traffic. Brymen already provided you with the protocol. So it's just a mater of looking through the data to see if the meter is sending the bad data. If not, we know it is something with the phone or Android application. You know what you are looking for and can use their spec to determine the packet that would create that fault. From there, just do a search.It's most likely caused by the meter or the phone, not both. You should be able to answer that pretty easy.https://www.wireshark.org/docs/wsug_html_chunked/ChWorkFindPacketSection.htmlOf course, if you repeat your tests using the new application and it does not fail, then maybe repeat running to original version again, and you find it does correct it, we have our answer.

author: EEVblog
author_rank: Unknown
timestamp: May 14, 2025, 03:36:19 am
content: Running the new 1.6 firmware for 1.5hours I didn't get a single dropout. Phone across the other side of the lab as before.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 14, 2025, 03:38:23 am
content: Quote from: EEVblog on May 14, 2025, 03:36:19 amAnd if you run the old app again, does the problem return?

author: joeqsmith
author_rank: Super Contributor
timestamp: May 14, 2025, 03:41:41 am
content: Just in case you missed it, again you do need some hardware to use WireShark with BLE.https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg5885602/#msg5885602

author: EEVblog
author_rank: Unknown
timestamp: May 14, 2025, 06:20:03 am
content: Ran the old 1.0.58 app (it doesn't overwrite when you install the new version) and Ididn'tget an data drops in 1/5hrs again (26400 samples).So something else is going on here, perhaps interference related.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 14, 2025, 01:45:45 pm
content: That's not good. Did you conduct these new tests using resistance mode with the same 1k resistor you originally used?I have tried sweeping the resistance value when using my software and saw no problems but maybe it has something to do with what you saw.I wouldn't think interference from other sources would be a problem. Similar to how we are able to send so much data over the internet with countless other traffic, Bluetooth is similar (actually why I suggested WireShark). When I tried running these tests at work, I also get a lot of traffic but was never able to replicate the 10X.Brymen did contact me about reinstalling the application for the iPhone. The short story, I now have the 0.1.20 firmware installed. These changes did not improve my connection problems when using the Andoid phone. The iPhone on the other hand seems to work fine. I understand they received their BLU G64 phone. Hopefully they are able to find the incompatibility problem. At a minimum, I think the more phones they test, the more robust their application will be.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 14, 2025, 02:11:18 pm
content: I do not know what they changed with the radios firmware but it did not appear to effect the operation. Shown, I had take the meter with resistor substitution box for a walk, switching different values while forcing some dropouts (note updated firmware). It wouldn't make a lot of sense that this would cause a problem. You're a mile away from the switch point. Still, I wouldn't rule anything out at this point. Something obviously was causing it.Also note that even with these dropouts, there are no CRC faults detected. This is what I was suggesting that BLE should handle that at a lower level.With the iPhone now able to program the firmware, I think the next step will be to sniff that traffic during the process and see if I can answer some of the questions I have about how they have implemented the OTA programming. I just need to steal my wife's phone which is going to be easier said than done!

author: floobydust
author_rank: Super Contributor
timestamp: May 14, 2025, 04:41:44 pm
content: I'd take a sig gen and resistor and modulate the resistance seen by the DMM by a very tiny amount, at the rollover value. With a LF sine or square wave maybe.Causing the DMM some jitter, example reading 1.0005k to 999.90 so it's at going back and forth centered at the rollover/range/exponent change, at say at 1Hz.If Brymen firmware doesn't use proper semaphors, the read and write of the reading data structure would not be atomic.I'm saying (as a guess) the BT thread reads shared memory holding the last reading, but while the DMM thread is updating it with a new reading- but decimal pt has moved.Or the BT module messes up reading the long term verses short term average the DMM has and switches between. Just giving some ideas of thing to flush it out, instead of waiting for it to appear.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 14, 2025, 05:48:22 pm
content: Quote from: floobydust on May 14, 2025, 04:41:44 pmI would say this is a very good idea and one I had ran with this meter but not straddling the 1k arbitrarily selected test point. This would be very easy for me to setup such a signal (see attached triangle wave at 0.05, 0.1, 0.5 & 1Hz). Then increasing the amplitude to get roughly the same p-p value.While you suggest the problem is on the meter side, I don't know that. Hence asking about about sniffing the communications. I could run this test using the phone but it can take upwards of an hour an a half just to connect with the meter. However, if the problem is with the meter, I am now running the same firmware for both the radio and DMM as Dave's. It should reproduce with my Windows application. I'll let it run like this for a few hours but I doubt very much we will see anything.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 14, 2025, 06:17:28 pm
content: One thing to mention is that is not some floating point number. If you read their document, that decimal point will have a fixed location within the five digits the meter sends (in the case of this 1k ohm test). What it sends would be 1.0005k to 0.9995k for example rather than 1.0005k to 999.90. If the phone presents the later, it is because the phone is reformatting the data. In my software, the large readout is the decoded ASCII data. This is then changed to a float which is graphed (and other processing).Shown with a bit over a half hour of data collected. Nothing particularly of interest in the data but I will allow it to run a while longer.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 14, 2025, 07:33:26 pm
content: Over an hour and a half of dithering the data about the 1k ohm as suggested, not a single 10X glitch. Maybe Dave will try it for you using his meter and phone.

author: floobydust
author_rank: Super Contributor
timestamp: May 14, 2025, 07:45:02 pm
content: That was fast but no fruit on your bench it seems.I'm looking at the big packet of 152 bytes. The reading is sorta floating point in that there are 3 bytes with the Mantissa [21,22,23], and then the Characteristic (exponent) gets assembled from [24,27] I think.The 32-byte "Device Reading Packet" portion, bytes 24 and 27. Maybe they are the ones giving trouble? So I was thinking about working them to check the edge conditions. Reading Decimal Point (depends on # digits displayed) Display Digit Number (3 or 4 or 5 or 6 digits displayed)Does the meter on Ohms keep a constant number (5?) of digits? Or does it slide over when below 1,000.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 14, 2025, 08:55:41 pm
content: I did lower the amplitude to improve your odds and let it run a while longer but as you can see it had no effect. I have collected several hours of data with this meter over the Bluetooth interface and have never seen what was described. You would think at some point I would have run into it but again, we do not have the exact same setup although I am taking steps to minimize those differences.Quote***For example:1 ohm = 001.000.01 ohm = 000.01***I believe so. The number of leading zeros and location of the decimal point will change is all. For this particular case, the decimal will remain fixed. Now in Dave's 10X case, the decimal may have shifted right but I think the actual data was outside the meters max count. You would need to go back and read his posts. Basically I thought what he showed made no sense at all. I would have bet the farm it was the Andoid application but the limited amount I have used it, I was still unable to replicate the problem.Do a deep dive on that document. If you have any questions about it, feel free to ask. If you come up with some other test that you think could force this fault, let me know and I will see if I can set something up.***Quote from: EEVblog on April 18, 2025, 03:41:46 am

author: joeqsmith
author_rank: Super Contributor
timestamp: May 15, 2025, 01:05:38 am
content: Shown is data I collected using the same meter and radio firmware revisions as Dave's test. Same Android application revision. The meter and phone are not the same hardware and the phone's are using a different versions of Android.

author: EEVblog
author_rank: Unknown
timestamp: May 15, 2025, 03:07:24 am
content: Quote from: joeqsmith on May 14, 2025, 01:45:45 pmYes.Will run it again today for longer.

author: EEVblog
author_rank: Unknown
timestamp: May 15, 2025, 06:14:24 am
content: Wow, 52000 samples and I got a whole bunch of dropouts on v1.0.59 today.Only physical environment difference is I had the aircon on.Will try again with v1.0.60

author: EEVblog
author_rank: Unknown
timestamp: May 15, 2025, 07:32:13 am
content: Short 20,000 sample test on 1.0.60 with aircon on done, no drops.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 15, 2025, 02:23:01 pm
content: Could you please post or email me the data you recorded when the glitches occur.Do you remember if your A/C was running during the time when you first noticed the 10x glitches?Beyond running that new application with the same setup, A/C on or off, for as long as possible, I'm not sure what else you could do. I wonder if the A/C actually played into it, or was something else going on.Brymen was able to replicate the connection problems I am having with the BLU phone.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 15, 2025, 10:02:17 pm
content: Also, I am curious if you are seeing any problems with the files not being saved during longer collections?

author: EEVblog
author_rank: Unknown
timestamp: May 15, 2025, 11:14:14 pm
content: Quote from: joeqsmith on May 15, 2025, 02:23:01 pmDon't recall.I only noticed it because I happen to be running specific lab air quality measurements that need me to have the aircon or or off all day.QuoteNeeds more testing I guess.At the moment, v.1.0.60 seems to have fixed it. But again, more testing required.

author: EEVblog
author_rank: Unknown
timestamp: May 15, 2025, 11:15:01 pm
content: Quote from: joeqsmith on May 15, 2025, 10:02:17 pmBiggest one so far is 3 hours. No problems apart from it taking a bit extra time to process before the save button comes up.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 16, 2025, 12:29:17 am
content: I have lost files a few times when using the phone. Today I let it run about 5 hours. It took a very long time to prompt me for the file but eventually it looked like it had saved. Using the PC to transfer the data to the PC, it had 0 Bytes. The phone has plenty of storage space but it could be another incompatibility.It's always that 9.9996. Everything is stable before and after. The decimal point is in the correct location but it acts like the digits were shifted left and you gained that 6 digit. If you try this with some other value that is less consistent (0.1234 for example), do you see a similar shift?As a last ditched effort to remove one more variable, I am attempting to modify one of the BM786 meters to a BM787BT. I will also trim my resistance to match yours. Even if I am unable to replicate what you are seeing, I hope to test their applications with more than one source.

author: EEVblog
author_rank: Unknown
timestamp: May 16, 2025, 12:55:30 am
content: Quote from: joeqsmith on May 16, 2025, 12:29:17 amI'll try that after another v.1.0.60 test running now.QuoteYou'll have to physically swap the processor as well to get the firmware change, not sure I see the point in that?

author: EEVblog
author_rank: Unknown
timestamp: May 16, 2025, 12:59:46 am
content: Quote from: joeqsmith on May 16, 2025, 12:29:17 amThere might be a max sample number limit where something breaks.

author: EEVblog
author_rank: Unknown
timestamp: May 16, 2025, 02:26:31 am
content: Just found another issue.I was logging data and decided to take the phone and the meter in a bag to the post office and shops. This was the first time I had locked the phone during logging. I also used the RFID to pay for something.Even after all that I could still see the program was logging as I scrolled through the open apps.But when I got back to the lab and lunlocked thep hone switched the logging app, it was disconnect and the logged data was all gone

author: joeqsmith
author_rank: Super Contributor
timestamp: May 16, 2025, 03:10:20 am
content: Yes, when during those first tests where I walked away from the meter carrying the phone to force the drops, I would often loose the data. These tests were over a few minutes rather than hours. You could try that very easily. With mine, the phone's screen will blank out when you pushed it too far.>>You'll have to physically swap the processor as well to get the firmware change, not sure I see the point in that?I thought I have been clear about that. The point is to try and reproduce what you are seeing with those 10x glitches. Part of that is removing unknown variables.

author: EEVblog
author_rank: Unknown
timestamp: May 16, 2025, 03:27:12 am
content: Quote from: joeqsmith on May 16, 2025, 03:10:20 amI don't see how the meter hardware can be the problem.But ff it is the problem, i don't see a mechanism where there is a difference/fault in the hardware between boards.Not impossible, but seem like the most remote possibility

author: EEVblog
author_rank: Unknown
timestamp: May 16, 2025, 03:28:05 am
content: Quote from: joeqsmith on May 16, 2025, 03:10:20 amYeah, I can test that quickly. Will do that after the current logging.

author: EEVblog
author_rank: Unknown
timestamp: May 16, 2025, 04:31:32 am
content: Quote from: joeqsmith on May 16, 2025, 12:29:17 amJust did 26,000 samples of 0.1234k and got no dropouts on v1.0.58White coat syndrome

author: EEVblog
author_rank: Unknown
timestamp: May 16, 2025, 07:13:06 am
content: I can't recreate the data loss by locking and unlocking the phone, switching apps, etc. v1.0.60

author: joeqsmith
author_rank: Super Contributor
timestamp: May 16, 2025, 01:24:51 pm
content: Just try walking away until it drops connection, or turn off the meter during a collection. These tests would be easy for me to run if the phone would just link.I finished up with my mods to convert the BM786 to the BM787BT. This meter was not subjected to my battery of tests, and has all of the later mods made just prior to the release. It should be very close to what you are testing.To achieve the same value, I just shunted my 1k.Quote from: EEVblog on May 16, 2025, 03:27:12 amI am not ruling anything out at this time. Being unsuccessful in replicating what you have shown, I am just removing variable the best I can. If it were to reproduce, the first thing I will do is fire up Wireshark and start splitting the problem down.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 16, 2025, 01:58:43 pm
content: It took about a half hour but the phone finally linked to the meter.The plan is to let it run about 9 meters away for some time. I have no idea what your A/C would produce for noise, but I had tried using a spark gap transmitter to create some broad band noise. These can easily take out the USB bus and do a number on my scope.. I had tried this with the BM788BT yesterday but it had no effect. Bluetooth seems fairly robust as long as there is decent signal strength to work with.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 16, 2025, 03:00:26 pm
content: A bit over 1 hour, with same meter, same firmware in radio and DMM, same Android app. Roughly 9 meters, still no luck. The phone is still different.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 16, 2025, 05:29:51 pm
content: A second test, moving the modified BM786 meter even further away and logging from the phone as before. Later the BM788BT was placed next to the BM786 and was logged using the PC. Located a couple of meters from the PC and phone, my spark gap transmitter....After running for a bit over an hour and a half, no faults were detected. I am at a loss of what is causing the problem you are seeing. The phone I am using is unlocked without a card. It's for testing purposed only (I have no use for a cell phone). Maybe something happens when you get spam calls or something else related to the phone.Just an FYI, I don't consider the multiplier when importing the phone's data files. I may do this once they settle on a new file format (you mentioned this was changing).

author: EEVblog
author_rank: Unknown
timestamp: May 16, 2025, 09:49:59 pm
content: Quote from: joeqsmith on May 16, 2025, 01:24:51 pmBut you don't have the 787BT firmware, you are running BM788BT firmware on a BM786 base board, correct?Brymen have seperate firmware branches for every model. Extremely unlikely there is a difference there, but possible.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 17, 2025, 12:37:48 am
content: Quote from: EEVblog on May 16, 2025, 09:49:59 pmIncorrect. Prior to this mod, I also mentioned I had been testing with the 787 firmware loaded onto the 788. See previous post:https://www.eevblog.com/forum/testgear/new-brymen-bluetooth-bm787bt-multimeter/msg5916818/#msg5916818

author: EEVblog
author_rank: Unknown
timestamp: May 17, 2025, 01:34:33 am
content: Quote from: joeqsmith on May 17, 2025, 12:37:48 amI didn't think you had a programmer?

author: joeqsmith
author_rank: Super Contributor
timestamp: May 17, 2025, 08:53:51 pm
content: Just an FYI, when adding Bluetooth to the BM786, the calibration was completely invalid. I have no way to align the meter, but because I was only interested in the resistance mode, I hand sorted some low temp co film resistors to do a poor man's alignment. To use this meter for any kind of performance verification would require a full realignment and calibration.Basically, customers should not expect to be able to hack these meters to add this feature.***When I wrote completely invalid, for example, with the leads open the meter would display 240 ohms or so. It was so bad, I actually thought I had damaged the meter. After installing the original firmware, the meter returned to normal. It was not just the resistance but other modes as well.***Shown after BLE firmware mod with diode check open and 5VDC reference.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 18, 2025, 09:18:30 pm
content: After poor mans ACV alignment using original BM869s as a reference.***(correct photos)

author: joeqsmith
author_rank: Super Contributor
timestamp: May 18, 2025, 09:30:52 pm
content: To get the basic meter working again, I readout the coefficients from the BM788BT and transferred those to the modified BM786. Knowing full well that the AC stages are completely different. This is why I realigned the ACV in previous post (otherwise it would just read 0). Goal again isn't to get decent performance out of the meter but get it close enough to be able to use it to collect data using the BLE interface. I left the DVC/mV as is. Diode check now over limits when open. Fairly close considering...Also shown up to 1kDC. Again, consider these coefficients are from a completely different meter. It gives you some idea how tight their design/parts/build are.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 18, 2025, 11:55:30 pm
content: I went back and aligned the mVAC/DC and DCV using the HP34401A as a reference. The three Brymen meters now track up to 1000VDC. Much better.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 19, 2025, 02:57:51 am
content: Both meters attached to the Applied KiloVolts. PC linked to the BM788BT and the Android linked to the BM786. There is a few seconds phase difference due to me manually starting things.Looking at the data between 1100 and 16000 samples, the two meters stay within a couple of counts of one another. (not bad for a poor man's alignment). There is one 14 count spike with the BM786 that did not show up with the BM788BT. Far from a 10X shift. Not sure what would cause it.It took about an hour and forty five minutes for the phone to link to the meter. It took more time to connect than it did to collect the data. Hoping Brymen is able to resolve this soon.

author: EEVblog
author_rank: Unknown
timestamp: May 19, 2025, 05:54:27 am
content: 43,000 samples logged for a 0.1234k resistor on v1.0.58, zero dropouts. Can't cop a break

author: joeqsmith
author_rank: Super Contributor
timestamp: May 19, 2025, 01:29:22 pm
content: Did you try to turn off the meter to break the connection while logging and seeing if the data was saved?What would be so magical about a 1k?If it likes that value, if you just raise it a bit to 1.234k, maybe you will get lucky and we can see if it shifts the data.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 20, 2025, 01:56:30 am
content: To tighten the 3M I sorted a closer part which was a bit too low. Added additional R to finish it off. Of course, how close is my old HP34401A. I need a better meter than my even older HP 3468A to answer that. Rabbit hole is getting a bit too deep.

author: EEVblog
author_rank: Unknown
timestamp: May 20, 2025, 04:20:08 am
content: Quote from: EEVblog on May 16, 2025, 04:31:32 amAnother 28,000 sample run of 0.1234k and got no dropouts on v1.0.58. This time I turned on the battery saver thinking it might be that. And I rebooted the phone just in case.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 22, 2025, 02:17:44 pm
content: Maybe it only has the problem at the 1k switch point. You could try 0.9876 k or 1.2345 k. Or go up to 10k. You could also try the dither test that was previously mentioned. With it being so apparently random, it may not reproduce no matter what you set it to. The other option is just stay with the newer application with the CRC check and see if it ever shows up again.I have not heard anything from Brymen for a few days. Guessing they are working on resolving some of the remaining problems.

author: EEVblog
author_rank: Unknown
timestamp: May 23, 2025, 03:59:31 am
content: Quote from: joeqsmith on May 19, 2025, 01:29:22 pmIt's most likely nothing to do with the value at all. As evidenced by having done the 1k test and got no dropouts.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 23, 2025, 12:21:47 pm
content: Quote from: EEVblog on May 23, 2025, 03:59:31 amI thought the only time you have had it fail was with the 1k? If not true, can you post the raw data for the other failures as well?

author: EEVblog
author_rank: Unknown
timestamp: May 23, 2025, 11:07:34 pm
content: Quote from: joeqsmith on May 23, 2025, 12:21:47 pmCorrect, but I've also had it NOT fail on that same 1k, twice.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 24, 2025, 12:11:47 am
content: Quote from: EEVblog on May 23, 2025, 11:07:34 pmTo prove it is not related to the original 1k, you will need to show it can occur with something else.Is Brymen still planning to ship your first units next month?

author: joeqsmith
author_rank: Super Contributor
timestamp: May 25, 2025, 08:11:11 pm
content: Saw your latest video with the Keysight Bluetooth battery leakage. Was your plan to use it to compare with the Brymen meter? With the expiration date of those batteries, looks like you had not used it in over a decade.It does show the exact problem when companies close source these interfaces. Really happy to see Brymen open it up to the public.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 25, 2025, 10:58:18 pm
content: Showing the modified BM786 to BM787BT with t8712 firmware, 1.20 radio firmware and 1k resistor. Total time was a bit over 29 hours. The batteries in the meter then too low and the connection dropped. I suspect this is also why I was seeing an additional count of change over the last 12 hours or so, getting worse until the test stopped.This data was captured using the PC without the CRC correction. However, no CRCs were detected during this test.The typical transfer time is 0.2 second or 5Hz (for the resistance function). Notice that towards the end there were samples that required much longer but the software was able to recover the connection. None of these caused any problems with the data.If anything, any problems continue to seem to point to the phone, not the meter.

author: EEVblog
author_rank: Unknown
timestamp: May 27, 2025, 05:43:59 am
content: Quote from: joeqsmith on May 25, 2025, 10:58:18 pmI just tested for 3 hours or so and I heard the meter beep, turned out it had switched off due to the low battery alert, but the app lost all my data. I could save the data to CSV but it was empty. I'll report that as a bug.

author: EEVblog
author_rank: Unknown
timestamp: May 27, 2025, 05:47:58 am
content: Quote from: joeqsmith on May 25, 2025, 08:11:11 pmNo.Don't know if they are still shipping. I'd like to see the Windows and Apple apps first.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 27, 2025, 11:54:42 am
content: Quote from: EEVblog on May 27, 2025, 05:43:59 amI had reported it as well. They responded today and it sounds like a fix will be soon.The problem with the BLU phone sounds like it will be more complex to solve, but they are working on it.QuoteIf you have an iPhone, I would think they would allow you to test that application as well. I can't steal my wife's phone long enough to run any long term tests with it.I have not heard about a Windows, LINUX or MAC application.

author: EEVblog
author_rank: Unknown
timestamp: May 27, 2025, 12:12:29 pm
content: Quote from: joeqsmith on May 27, 2025, 11:54:42 amYes, it was already on the list of fixes for the next version.QuoteI don't have a modern Apple phone. They mentioned Windows to me, but I checked email and it's "iOS APPand/orWindow base software"

author: joeqsmith
author_rank: Super Contributor
timestamp: June 14, 2025, 01:47:59 pm
content: I see they updated their applications for both the iPhone and Android to correct the problems with data loss during a disconnect.They continue to investigate the compatibility problems with my BLU G64 and I understand have expanded to testing with other Android phones as well. Being completely clueless about these phones, I was surprised to hear just how different the hardware is.I have stopped all testing for now.

author: EEVblog
author_rank: Unknown
timestamp: June 17, 2025, 09:01:10 am
content: Quote from: joeqsmith on June 14, 2025, 01:47:59 pmI just tried it with a flat battery meter and got 13,000 reading before it dropped out and the meter switched off. The app handled it just fine and allowed me to save the data no problem.Also, no x10 problem with 0.123k

author: joeqsmith
author_rank: Super Contributor
timestamp: June 17, 2025, 10:12:20 am
content: Because of this new meter, I went from never owning a cell phone to now having three of them. None with service.I did try the new app and also found it would allow me to save the data but my tests were minimal.Now that you know you will not loose your data, I guess you could try a long term test with new batteries to get a feel for life. Maybe just use the same brand/model that were supplied. What I saw early on is the link can start to drop before the low battery indicator comes on. It acts like there is a surge of current. I have not looked into yet. May make for a decent short video on your second channel.

author: EEVblog
author_rank: Unknown
timestamp: June 18, 2025, 01:39:08 am
content: Quote from: joeqsmith on June 17, 2025, 10:12:20 amI'll need to dig out an old photo for that if I'm actually logging. Not that that would make any actual difference to a battery life test, just leave the meter with data mode turned on.

author: joeqsmith
author_rank: Super Contributor
timestamp: June 18, 2025, 03:23:06 am
content: When the BM788BT is advertising, it broadcasts 20 bytes (+ overhead) every 2.5 seconds. Once notifications are setup, the meter will send 152 bytes at up five times per second depending on the function selected. I have yet to look at battery life and don't know how much it costs to send the notifications compared to the broadcast. Also, it looks like when I measured the latest version of the BM789, the peak current for all the modes was 6.71mA (no backlight or beeper).In other words, consider running the test with the meter connected and logging. Then maybe just document which function was selected. If you choose to log the data, you may want to use the same 1k resistor you used when the 10X glitches were showing. With it being a long term test and new software, it may help build confidence that the problem is solved. The other thing that may be of interest is how the lower battery effects the readings. I noted there was an error towards the end of that 24 hour test. It may be helpful to quantify that error.I also suggest running the test with logging using the latest application just to build confidence that the system is robust enough to actually collect data for an extended period of time.

author: joeqsmith
author_rank: Super Contributor
timestamp: June 20, 2025, 05:28:38 pm
content: If you would like to compare some measurements, I set the battery voltage to 4.5V Then monitored the current with the meter in the AC VFD mode while I changed the BLE from off to advertise to notify. It appears to draw about 400uA more to notify vs advertise. We knew it wouldn't be free. I don't know what the cause of the current spike is when it first starts sending the data.With notifications, I then adjusted the supply down. The low batter begins to flash as 3.52V. At 2.4V, the LCD is washing out. Maybe half contrast. At 2.3, I lost connection.All of that seems fairly normal. Now the strange part. I adjust the voltage to 2.5, the meter will not turn on. Eventually at 2.9 it does, but it turns back off. I think that the meter will turn off the power, even if the auto power off is disabled depending how lot the battery is.If I let it continue to log data, I see these current spikes at some random interval. What ever is going on, it seems to stall the communications. Maybe an ADC autocal or something.

author: joeqsmith
author_rank: Super Contributor
timestamp: June 20, 2025, 07:08:06 pm
content: Running the normal battery check sequence and comparing with/without the BLE active (notification when active). Comparing with the released BM789, you can see that maybe Brymen turned down the backlight. Other than that, when BLE is turned off, the two meters basically track.The battery life between the two is basically a wash when BLE is disabled. When logging, it looks like you loose about 30 hours of run time. Not too bad really.

author: EEVblog
author_rank: Unknown
timestamp: June 20, 2025, 11:22:28 pm
content: Quote from: joeqsmith on June 20, 2025, 05:28:38 pmYes, I've noticed that.

author: EEVblog
author_rank: Unknown
timestamp: June 20, 2025, 11:40:26 pm
content: Brymen want to know if I want the meters in July, or wait until the Windows version is also available, but they can't give me a date on that.The Android/iOS app uses the exact same code base, so both of those are available at the same time with the same fixes/bugs.

author: joeqsmith
author_rank: Super Contributor
timestamp: June 20, 2025, 11:52:08 pm
content: I understand Brymen is going to supply you with a list of cell phones that have been qualified to work with their application along with those with known compatibility issues.I have never talked with them about their Windows application.

author: joeqsmith
author_rank: Super Contributor
timestamp: June 23, 2025, 02:15:53 pm
content: Just an FYI, with the new cell phone and latest Android application, using my modified BM786 (BM787BT) with all the latest firmware, I was FINALLY able to replicate your 10X failure using the resistance mode with 1k resistor. I strongly suspect now that the problem lies within the phone application as I have yet to see it when using my own custom application with the PC. I have passed that data onto Brymen along with some other test data I collected. At least we now know it is not unique to your setup and the addition of the CRC did not correct it.2025-05-26,21:28:40.239,BM78xBT,#channel1,Resistance,9.9996,k,Î©

author: EEVblog
author_rank: Unknown
timestamp: June 23, 2025, 11:00:22 pm
content: Quote from: joeqsmith on June 23, 2025, 02:15:53 pmWow, nice work, thanks, I wasn't going crazy.I'm going to get an Apple shoe phone and they are putting me on the Apple beta app program.

author: joeqsmith
author_rank: Super Contributor
timestamp: June 25, 2025, 12:08:33 pm
content: Brymen thinks the 10X bug may have been addressed with these latest changes. They have also release a new application for the Android today (store only). They have started to run long term tests and have asked if I could repeat it as well using the latest updates. Good to see them getting these problems resolved prior to the release. Seeing all three of those Android phones working smooth with both meters was a big milestone.

author: joeqsmith
author_rank: Super Contributor
timestamp: June 26, 2025, 01:05:33 am
content: Before running this next test to see if the 10X bug will replicate with all the latest changes, I hacked up a AA battery pack to give me an even longer run time. Who has concerns for safety when measuring a 1k resistor??IMO, the highest priority problem I would go after is how the sampling rate slows the longer you collect data. This is not a problem when using my custom software + PC. Brymen is investigating this problem.

author: BILLPOD
author_rank: Frequent Contributor
timestamp: June 27, 2025, 01:53:44 pm
content: Good Morning Joeqsmith, I too never had a cellphone until I started accumulating meters that have Bluetooth and can display/record data. My Mooshimeter was my first candidate. So, I went to Amazon, looking for an inexpensive cellphone. I got the BLU model G61S. I have several Bluetooth capable meters and they all connect to the phone. I haven't checked if there are any 'drop-outs' when recording data, but my problem is range. I can't get a signal once I get approx. 6 ft. away. What kind of range are you getting

author: joeqsmith
author_rank: Super Contributor
timestamp: June 27, 2025, 02:35:03 pm
content: Quote from: BILLPOD on June 27, 2025, 01:53:44 pmHello Bill. I have not yet tried any range tests with the Motorola or the Unnecto. The BLU G64 can communicate from my upstairs to my downstairs living room which is maybe 30 or 40 feet. I think Dave was testing at 9 meters or 30 feet. I took the BLU and meter to work to test it in a high traffic environment. I was at least 40 feet away but that was line of sight.I did a test several years ago using a cheap tablet to communicate with Dave's 121GW, Gossen Ultra, UNI-T UT181A. All of those worked far beyond 6 feet. Time stamped with Dave's meter, maybe 20' or so.https://youtu.be/e_YzwO62feQ?t=622***While on the subject, when I finally replicated the 10X fault Dave found, I had the phone and meter right next to one another, at my home which is a very low traffic area. What ever the cause, it doesn't seem related to a weak signal or heavy traffic. I have been running with their latest firmware and application with the same phone and modified BM786 (to simulate Dave's meter) for about 2.5 days now. The plan is to let it run for at least five days to see if the updates had any effect.

author: EEVblog
author_rank: Unknown
timestamp: June 28, 2025, 08:58:42 am
content: Quote from: joeqsmith on June 27, 2025, 02:35:03 pmThat's interesting.

author: BILLPOD
author_rank: Frequent Contributor
timestamp: June 28, 2025, 01:34:59 pm
content: Thank you Joe, the short (<6 ft), range is apparently the fault of my BLU61S phone, as none of my bluetooth equipped meters work beyond 6 ft. I would be very happy if I could get even 20 ft. I got the cheapest new phone I could find and I guess I got what I paid for.However, all is not lost, as I get some use out of the phone as a 'tablet'. Thank you for your response.

author: joeqsmith
author_rank: Super Contributor
timestamp: June 28, 2025, 01:40:20 pm
content: I would like to know if your iPhone produces the 10x problem and if you experience a reduced sample rate for longer data collections.It's a bit odd that the 10X fault produces the exact same value every time with both your an my setups. Their application appears to save everything into the phone's RAM while it is collecting. It doesn't offload it to NVRAM until you complete the collection. I don't know why they don't create the file at the start of the collection and stream the data to NVRAM, the keep a limited amount in RAM.Anyway, I wonder as the phone starts to clog up with all that data and slow down, is this somehow causing the false 10x reading. When I replicated the fault, the phone had ran for a fair amount of time and was slowing down. In my case, the phones have no SIM card, and very little software is loaded onto them. If the phone was actually being used as a typical phone, maybe the resources required can cause the fault more often and earlier in the collection.All pure speculation on my part.

author: joeqsmith
author_rank: Super Contributor
timestamp: June 28, 2025, 03:07:04 pm
content: Quote from: BILLPOD on June 28, 2025, 01:34:59 pm$50 Motorola MotoG Tracphon

author: BILLPOD
author_rank: Frequent Contributor
timestamp: June 29, 2025, 02:07:29 pm
content: Thank you for the distance test on your $50 phone. I haven't done any open air distance testing, but I'm sure my $80 BLU 61S couldn't have done as well. Indoors, the walls and floors do have an impact on distance, but my 6 ft. max. is in the same room with nothing between meter and phone. I'll have to try Mother's phone, but prying it from her hands is another difficult challenge. I'll try a used phone off Ebay and see what I get. I love your dog; she is a real sweety. Thanks very much for your help, Joe.

author: joeqsmith
author_rank: Super Contributor
timestamp: June 29, 2025, 08:18:40 pm
content: Glad to help.

author: joeqsmith
author_rank: Super Contributor
timestamp: June 30, 2025, 06:59:20 pm
content: Dave's hiding the battery life testing for the BM787BT under his review of a UNI-T meter. I asked Brymen about the spikes. Sounds like they try to put it into sleep mode as much as possible to save battery life. " BLE power consumption in Active mode is much more than in Sleeping mode and introduce those current spikes. "https://youtu.be/dv3kIiqOQOw?t=1819

author: EEVblog
author_rank: Unknown
timestamp: July 12, 2025, 06:24:47 am
content: Apple shoe phone test:

author: mlord
author_rank: Newbie
timestamp: July 12, 2025, 01:43:00 pm
content: Quote from: BILLPOD on June 29, 2025, 02:07:29 pmThe BLUG64has Bluetooth/BLE5.0, whereas the older BLU61Shas Bluetooth/BLE4.2.There's a4Xrange improvement with 5.0 compared to 4.2.That may explain why the BLU 61S isn't doing very well with distance.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 12, 2025, 03:34:29 pm
content: Quote from: EEVblog on July 12, 2025, 06:24:47 amIt would be very interesting to see if you can replicate that 10x fault with that iPhone.I mentioned that you could use Wireshark with that Adafruit BLE radio to sniff the traffic. It turns out that it does not support the larger MTU sizes required by Brymen, or at least I could not figure out how to make it work. Not having the proper tools to debug it, about all I can do is run it.***One other thing that may be helpful... When running their application, it shows the min and max readings. I only check the test a few times during the day and have never seen the max display anything odd. Have you?

author: EEVblog
author_rank: Unknown
timestamp: July 13, 2025, 12:47:53 am
content: Was testing last night but the battery pack and phoen died, so lost everything.The iOS app stops logging and prompts to save data if the phone goes out of range. That's annoying, what if there is a short interruption? I'd rather have a bit of lost NULL data in that case than the logging stop.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 13, 2025, 01:59:08 am
content: QuoteThe older version of the application lost everything when the connection drops. At least now it allows you to save it. I am not sure how they handle disconnects now.I keep the phones plugged in when running these longer tests. Currently both are at about 1.5 days. The peak readings are still at 1k.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 13, 2025, 02:13:30 pm
content: I did open circuit the meter during the test. The max went to OL as expected and remained that until I decided to restart it today. I would expect if it glitched, we would see the max level reflect it, but also, I have never seen the 10x spikes in the plots while collecting data.

author: EEVblog
author_rank: Unknown
timestamp: July 13, 2025, 02:20:23 pm
content: Today I was logging at home on the iPhone, phone upstairs, meter downstairs, was logging fine for hours until I was standing there watching it when I switched on the room light and the meter stopped logging and asked me to save the data. Not sure if the light was a coincidence or a cause, but it was within seconds of the event.It would then not reconnect at all to the meter regardless of how close I got. I had to restart the bluetooth on the meter before it would reconnect again.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 13, 2025, 02:48:51 pm
content: Do you feel the original version of the application more robust as far as the recovery? When I could get my phone to connect, if the connection was lost, it was pretty much game over. I posted about that here:https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg5886596/#msg5886596The most recent version of my software waits up to 4 seconds for meter to send the data. If nothing comes back, I keep the port open but turn off the notification (stops data collection). I then check if the meter is advertising. If it is, I resend the password and notifier, then restart the collection. If the meter is not advertising, it waits until it does or until I stop the collection. When I was trying to sort out how to recover from a disconnect, Brymen had told me that I would need to resend the password.I had tried temperature, battery voltage, sweeping the resistance over a small range, and using my spark gap transmitters to create some RFI. None of these effected the link.https://www.eevblog.com/forum/testgear/new-brymen-bluetooth-bm787bt-multimeter/msg5916858/#msg5916858But having the meter sitting right next to the phone, with nothing in the lab running (little RFI) and no traffic, then the phone disconnects.

author: EEVblog
author_rank: Unknown
timestamp: July 13, 2025, 11:13:11 pm
content: iPhone data logged all night, stopped it to save and got a "Extreme Memory Usage" warning, but it let me save the data anyway. But then it went into a doom loop and repeated the sam thing again, and again, saving each time and never exiting.It looked like the multipe files were there and it said syncing to iCloud, but I look an hour later and the files are not on my iCloud.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 14, 2025, 12:40:28 am
content: When I used my wife's iPhone, I don't think I actually saved any data. With the Androids, I have not had a problem saving local outside of it can take several minutes to save several days of data. Doesn't the iPhone allow saving it to local?I have about 2.5 days now with their updates. The one phone was reset after I forced the open circuit, but the other has been running non-stop. Both show a min/max of 1k. I plan to keep a closer track of the min/max until the meters disconnect. There may be a clue.

author: EEVblog
author_rank: Unknown
timestamp: July 14, 2025, 01:38:32 am
content: Quote from: joeqsmith on July 14, 2025, 12:40:28 amYes it does, but the iCloud lets me easily access it from the lab.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 14, 2025, 12:01:45 pm
content: I noticed how often updates/patches are pushed. I have no idea if this causes a problem during the data collection. Two of the phones have no sim card, and the other has no plan. I disable networking during these longer tests to minimize the number of variables we are dealing with.

author: EEVblog
author_rank: Unknown
timestamp: July 14, 2025, 10:15:21 pm
content: Another Extreme Memory Usage warning after a few hours last night. The iPhone app looks troublesome on my iPhone 11 Pro.

author: tautech
author_rank: Super Contributor
timestamp: July 15, 2025, 12:28:10 am
content: Quote from: EEVblog on July 14, 2025, 10:15:21 pmI imagine the IOS version is more important for bug diagnosis than the iPhone model #.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 15, 2025, 01:10:51 am
content: My wife's is an iPhone 12 Pro Max. One this long term test completes, I'll try it out overnight.

author: EEVblog
author_rank: Unknown
timestamp: July 15, 2025, 02:56:56 am
content: Quote from: tautech on July 15, 2025, 12:28:10 amIt's the latest 18.whatever

author: tautech
author_rank: Super Contributor
timestamp: July 15, 2025, 04:19:05 am
content: Quote from: EEVblog on July 15, 2025, 02:56:56 amThat Apple broke some of their own functionality with recent IOS updates and it took a further 2 or 3 updates to fix their shit so some consistency on the IOS version that you report any logging issues to Brymen might be a good idea.On 18.5 here......

author: joeqsmith
author_rank: Super Contributor
timestamp: July 15, 2025, 10:52:41 am
content: When I checked, both meters were powered off. Sadly, the one charger was unable to keep up with the phone and it also powered down. This caused it to loose all that data.1)Slow down of the application while logging2)Phone dropping the connection at random (not battery, low signal or outside RF interference)3)Unable to reconnect after a connection was made (requires restarting the application)4)Recorded data is 10x higher than actual and outside of meters range *15)If phone powers off due to low battery, data is lost *2*1 This last round of testing, using both meters for 4 days, the problem did not replicate with the latest updates from 7/11/25.*2 I am not sure why they don't ask for the file name first, then stream it to NVRAM rather than keeping the data in RAM.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 16, 2025, 12:54:51 pm
content: Another day of logging complete. The cheap phone did not come with a charger and I have changed over to a 2.5A one. Seems to be keeping up.I had looked at the data from the previous run and there were no 10x faults. The only disturbance was when I open circuited the leads. My plan is to run these two meters for the entire week.

author: EEVblog
author_rank: Unknown
timestamp: July 17, 2025, 10:38:22 pm
content: Apple logging overnight, went to save, and then the app shut down losing everything. iOS 18.5

author: joeqsmith
author_rank: Super Contributor
timestamp: July 18, 2025, 12:35:10 am
content: Can you use it to log over any length of time and save? Say 10 minutes?Does the iPhone slow down like I have demonstrated with the Android? With it appearing that they keep everything in RAM while logging, does your iPhone run out, or does the OS start swapping to NVRAM?***Also, have you turned off the wireless networking, cell phone carrier ... to make sure that nothing was going on in the background?My plan is to just run the wife's phone as is and see what happens but that's for a latter date after I finish this round of testing.

author: iMo
author_rank: Super Contributor
timestamp: July 18, 2025, 07:35:50 am
content: With android I've been using this BT terminal on my dedicated vintage Sammy S6 for logging .csv data off my 34401A:https://play.google.com/store/apps/details?id=de.kai_morich.serial_bluetooth_terminal&hl=usLogging works also in background and when the phone "sleeps" as well. Many settings..

author: EEVblog
author_rank: Unknown
timestamp: July 18, 2025, 10:54:22 am
content: No local saving on iPhones allowed.Quote

author: joeqsmith
author_rank: Super Contributor
timestamp: July 18, 2025, 12:06:55 pm
content: Quote from: EEVblog on July 18, 2025, 10:54:22 amQuote from: EEVblog on July 14, 2025, 01:38:32 amDid they change the application to remove that feature? You had stated that is was the same code for both platforms. Does this suggest that the Android will not save locally in the future?

author: joeqsmith
author_rank: Super Contributor
timestamp: July 18, 2025, 02:27:33 pm
content: While sitting here, one of the phones made some sort of chime noise. I looked on the screens and saw nothing unusual. Wi-Fi is off and they are both still at 100% charge. What ever it did, it does not appear to be effecting the data collection. I think this is day 4 of the second run.After running all these tests with the cell phones, while the hardware seems stable, the OS and software does not seem very robust. The idea that you would even need an internet connection to log data would be a major blow.

author: Rubo
author_rank: Regular Contributor
timestamp: July 18, 2025, 02:51:21 pm
content: Quote from: joeqsmith on July 18, 2025, 02:27:33 pmWelcome to 2025https://www.kohler.com/en/products/toilets/shop-toilets/numi-2-0-one-piece-elongated-smart-toilet-dual-flush-30754-pa?skuId=30754-PA-0Never thought a toilet would need an appThis is from 2020:https://med.stanford.edu/news/all-news/2020/04/smart-toilet-monitors-for-signs-of-disease.htmlQuote

author: joeqsmith
author_rank: Super Contributor
timestamp: July 19, 2025, 03:05:58 pm
content: I checked on the test last night and one of the meters had turned off. I am using the Eneloop AAAs. They seem to allow about 4-days of operation. I connected the Motorola Tracphone to the PC to pull down the data it's battery voltage was down to 32%. It was at 100% when I checked it in the morning. I am thinking that ding notifier had something to do with it. This is how I lost the data last time with this same phone. So, it's not the charger or cable. Something else is going on with this particular phone that it will not run for extended times. I tuned the backlight way down in hopes of improving it. At least this time I caught it in time so we have the data.The second meter was powered down when I checked today. So it ran a little longer with the same batteries. The Eveready Energizer Max that the meters were shipped with do much better. I wonder if they would consider lowering the threshold for NiMH.The bigger problem is that Unnecto phone seems to be hung. It also looks like the phone had tried to connect to the internet to update. Maybe that was the ding notifier I heard. It typically takes several minutes to prompt me for a file name, but it's shown the busy spinner for a little over an hour now. With 4 days of data in jeopardy, I plan to leave it at least another hour in hopes that it completes.

author: robert.rozee
author_rank: Frequent Contributor
timestamp: July 19, 2025, 03:52:40 pm
content: my own (albeit limited) experience with bluetooth is that it is:- fine for keyboards and mice, where the odd lost report doesn't matter too much,- moderately ok for audio, although many devices seem to become flakey over time as they age; i have yet to encounter a sound bar where the bluetooth didn't fail eventually and need to be replaced with a wired connection,- too unreliable for data connections where 100% integrity is paramount.might Bryman been better off (1) sticking to IR transmission of data, and (2) designing a recessed tray that holds a micro SD card that slides deep into the meter for logging data - the tray would be long enough such that it did not compromise CAT ratings.as an observer of this thread, while the bluetooth data logging and graphing is technically interesting, it seems to not be a feature that is suitable for use in any serious/professional environment.cheers,rob :-)

author: joeqsmith
author_rank: Super Contributor
timestamp: July 19, 2025, 04:26:01 pm
content: From my experience with these cell phones, I 100% agree with you. I have done a fair amount of data logging over extended times using BLE with custom software running on a PC. Even the new Brymen meter is very stable when used this way. Even with the PC, I certainly would not use it for life support.We have talked about user accessible memory cards before and the problems with safety and sealing. IR wise, now you are talking about adding a physical interface to the cell phone and much shorter distances. Again, I can't see this happening. Having ZERO knowledge of writing applications for any cell phone, I wonder if there is some reasons they chose to architect the software this way. Anytime I log data, I first setup the file and then stream the data to it. If power is lost, the data up to that point is still saved.It's been another hour and the Brymen application is still hung. I'll give it another hour but it looks like we lost 4 days of data again.1)Application's sample rate slows down while logging for extended periods2)Phone drops connection at random (not battery, low signal or outside RF interference)3)Unable to reconnect after a connection was made (requires restarting the application)4)Recorded data is 10x higher than actual and outside of meters range *15)If phone powers off due to low battery, data is lost *26)Application hangs when trying to save data*1 This last round of testing, using both meters for 4 days, the problem did not replicate with the latest updates from 7/11/25.*2 I am not sure why they don't ask for the file name first, then stream it to NVRAM rather than keeping the data in RAM.****I gave their application a full 3 hours to recover but no luck. The app was non-responsive to the touch screen. The only option was to force it to close. So far I have lost about half of the data I had planned on collecting before providing Brymen any feedback.

author: iMo
author_rank: Super Contributor
timestamp: July 19, 2025, 05:16:37 pm
content: So it is not about crappy BT per se, but the crappy app in the phone and/or meter. It needs a lot of finetuning to get it working reliably (it took 7 years with the app I mentioned above).PS: a simplified version on his github for android developers -https://github.com/kai-morich/SimpleBluetoothTerminalYou may look at how is the format of the raw data your meter is transmitting like, and perhaps logging it as the text or hex via the terminal is the reliable way to go.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 19, 2025, 06:41:46 pm
content: Quote from: iMo on July 19, 2025, 05:16:37 pmAs I said, all of the meters (including the new Brymen) work fine when used with my own custom software. Brymen has open sourced the protocol so anyone can view it.In this case, I think the problems are mostly with cell phone applications, not the Brymen hardware or firmware.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 19, 2025, 10:10:35 pm
content: The phone disconnected with the meter still powered up (#2) after a few hours. The odd thing is I count not get the phone to reconnect, even after restarting the application and power cycling the meter. Basically it detects the meter advertising, starts the link process, then fails stating the meter is disconnected. I tried 5 time to reconnect and always the same problem. So I turned on the Ethernet connection and as soon as I did, the phone connects to the meter.Maybe it was a coincident. All the other testing was performed with the Ethernet disabled to avoid updates and other variables. The was with the BLU G64. I'll leave the Ethernet active and see if the connection will stay up.1)Application's sample rate slows down while logging for extended periods2)Phone drops connection at random (not battery, low signal or outside RF interference)3)Unable to reconnect after a connection was made (requires restarting the application)4)Recorded data is 10x higher than actual and outside of meters range *15)If phone powers off due to low battery, data is lost *26)Application hangs when trying to save data*1 This last round of testing, using both meters for 4 days, the problem did not replicate with the latest updates from 7/11/25.*2 I am not sure why they don't ask for the file name first, then stream it to NVRAM rather than keeping the data in RAM.

author: EEVblog
author_rank: Unknown
timestamp: July 19, 2025, 11:50:41 pm
content: Quote from: joeqsmith on July 19, 2025, 10:10:35 pmNVM data wear. Continuously appending the file for every sample would be a bad idea.But yes, it should do this by buffering, so pick a number like 1000 samples before appending. Worst case you lose 1000 samples.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 20, 2025, 12:59:14 am
content: Quote from: EEVblog on July 19, 2025, 11:50:41 pmMy desktop PC is from 2016 and uses SSD. I treat the drive no differently than any other. All of my vintage TE which was Windows based was also converted to SSD and again, they get no special treatment. In that case, the drives handle the wear leveling. I am surprised a modern cell phone it's actually a concern. Consider people toss them out after a few years anyway.I suspect keeping it all in RAM is also the cause of the slow down. I wonder if the OS is swapping the RAM to NVRAM. The following is from one test. The first set is at the beginning, the second at the end.2025-07-15,21:52:51.124,BM78xBT,#channel1,Resistance,0.9999,k,Î©2025-07-15,21:52:51.329,BM78xBT,#channel1,Resistance,0.9999,k,Î©2025-07-15,21:52:51.542,BM78xBT,#channel1,Resistance,0.9999,k,Î©2025-07-15,21:52:51.741,BM78xBT,#channel1,Resistance,0.9999,k,Î©2025-07-15,21:52:51.949,BM78xBT,#channel1,Resistance,0.9999,k,Î©2025-07-17,19:00:27.640,BM78xBT,#channel1,Resistance,0.9998,k,Î©2025-07-17,19:00:29.291,BM78xBT,#channel1,Resistance,0.9998,k,Î©2025-07-17,19:00:31.149,BM78xBT,#channel1,Resistance,0.9998,k,Î©2025-07-17,19:00:33.003,BM78xBT,#channel1,Resistance,0.9998,k,Î©2025-07-17,19:00:34.860,BM78xBT,#channel1,Resistance,0.9997,k,Î©2025-07-17,19:00:36.719,BM78xBT,#channel1,Resistance,0.9998,k,Î©Consider that the early versions would only run on 1 of the 3 phones I have. They have made some very big improvements in the last few months. The loss of data and the fact it can't keep up IMO are the biggest problems they face.

author: iMo
author_rank: Super Contributor
timestamp: July 20, 2025, 08:05:14 am
content: .. also, as a test, try to switch off the WIFI in your phone (as well as switch off WIFI in your router)..and do power the phone with the charger while logging (with old batteries there might be a voltage drop while TXing via the BT or wifi)..If I were you I would try the android app I mentioned above (replay #199) - it should be no problem to log your ascii data with it (and we may help with setting it up).

author: joeqsmith
author_rank: Super Contributor
timestamp: July 20, 2025, 01:29:34 pm
content: Quote from: iMo on July 20, 2025, 08:05:14 amI have posted a few times about turning off wifi and running the phones of a charger. Readings not your strong point?As far as using some standard software to talk with the BM78xBT, Dave provided a link to their protocol specification. It's not some simple ASCII data as you seem to think. It may be possible to modify the software to support the Brymen.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 20, 2025, 05:06:23 pm
content: QuoteI thought I would be a little smarter and save the data before there was a problem. Both meters/phones were collecting the data as normal. I stopped the BLU/BM786 and saved with no problem. When I did this with the BM788BT/Motorola, it hung as I saw with the Unnecto last time. It's been displaying the spinner for about an hour now. I'll let it continue for the remainder of the day and just see if it ever shakes loose. In the mean time, I restarted the test with the Unnecto phone. Loosing 50% of my data is a real pisser. I assumed it was related to these really long collections but this was only about a day and again, everything was normal at the time I stopped the collection.1)Application's sample rate slows down while logging for extended periods2)Phone drops connection at random (not battery, low signal or outside RF interference)3)Unable to reconnect after a connection was made (requires restarting the application)4)Recorded data is 10x higher than actual and outside of meters range *15)If phone powers off due to low battery, data is lost *26)Application hangs when trying to save data*1 This last round of testing, using both meters for 4 days, the problem did not replicate with the latest updates from 7/11/25.*2 I am not sure why they don't ask for the file name first, then stream it to NVRAM rather than keeping the data in RAM.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 20, 2025, 11:43:05 pm
content: Since receiving the last update from Brymen, I was able to collect about 100 hours of data using various combinations of the three cell phones and two meters. While various problems caused me to loose about 40% of the data, the 10x fault never happened.Readers should be aware that that this fault was what they were attempting to address.1)Application's sample rate slows down while logging for extended periods2)Phone drops connection at random (not battery, low signal or outside RF interference)3)Unable to reconnect after a connection was made (requires restarting the application)4)Recorded data is 10x higher than actual and outside of meters range *15)If phone powers off due to low battery, data is lost *26)Application hangs when trying to save data*1 Fixed as of 7/11/25*2 I am not sure why they don't ask for the file name first, then stream it to NVRAM rather than keeping the data in RAM

author: joeqsmith
author_rank: Super Contributor
timestamp: July 21, 2025, 11:41:35 am
content: Looking at two of the data sets from the last round of testing with the latest updates. Showing the start and end entries and how many samples were collected for the set.2025-07-15,08:51:55.369,BM78xBT,#channel1,Resistance,0.9999,k,Î©2025-07-18,15:48:10.532,BM78xBT,#channel1,Resistance,0.9998,k,Î©416,0652025-07-21,00:49:12.378,BM78xBT,#channel1,Resistance,0.9999,k,Î©2025-07-21,07:01:51.649,BM78xBT,#channel1,Resistance,0.9999,k,Î©56,381We can see that the longer it runs, the slower it gets. The second set is for only 6hr 10mins. 370 mins @ 5Hz = 108,000 samples. Basically, half the expected data was lost.The attached image is showing 11 hours of data collected with the PC. The graph is plotting the time between messages received. There was one sample that required 2 seconds, but for the most part it is at the expected 5Hz and there is no sign of it slowing down. It's hard to believe that a cell phone would not have the hardware needed to keep up with it.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 22, 2025, 12:46:18 pm
content: Added the ability to trend the time between samples from the cell phone logs. Showing two different cell phones. Guessing that the less RAM available, the meter will slow down much earlier in the log.I have been testing with my custom application and am finding that the it will also disconnect at random. I suspect #2 may not be a problem with the cell phone. The second plot is again showing the time between samples when logging with the PC. After 16 hours, the connection dropped. Notice how the sample rate remained consistent over the entire run. There was one sample where it timed out at 10 seconds but recovered. I thought that early delay may have been a clue as to way the connection dropped but repeating this test, I did not detect the same timeout prior to the drop.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 22, 2025, 03:45:30 pm
content: Looking at all of the data sets collected with the latest updates, there were two cases where something happened that caused a very long delay between samples. One over 35 seconds, the other 22 seconds. From the slope of the change in sample rate, this was from two different cell phones. In both cases, their application managed to recover. Looking at the resistance measured, the long delays had no effect.Note you can see one setup has less noise than the other. I am using two different meters and resistors.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 22, 2025, 03:53:46 pm
content: There were 11 files total that were captured. Plotting the resistance for all of them, you can see they stay within 1.0002k - 0.9995k. You may remember my mentioning opening the leads during one run. This is the glitch shown in the data.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 23, 2025, 11:41:47 am
content: I heard back from Brymen who explained what was happening with the 10x fault. I have never seen it since their latest updates and believe this has now been addressed. Brymen has began working on the random dropped connection and loss of data. I provided them with some details about what I am seeing with the PC.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 23, 2025, 01:45:15 pm
content: BLE experts. From the following statements:QuoteI wonder when unacknowledged notifications are used, does the stack still send these empty packets to detect when the connection drops?Typically, if I move the meter far enough away from the PC for the connection to fail, the meter will begin to advertise. It will also send out the low battery status. I assume the meter knows the connection was dropped because of these empty packets being handled by the stack. On the PC side, my software doesn't send any data to the meter once collection has started but that does not mean that something is not being done at the lower stack or hardware layers to detect a link failure.Basically what I see with the PC when it hangs, the meter stops sending notifications but also fails to advertise. What ever state they get into, the only way I can seem to clear it is by toggling the BLE off and on. I suspect this is what is happening when I am using the cell phones and they hang (item #2). One other potential clue besides the low battery status being sent, I don't think I have ever seen the meter get into this state in less than 5 hours. Typically it happens after 10 hours or more of logging. It could be random. I have seen the cell phones drop connection within minutes of starting to log. Again, maybe random.I tried to use the Adafruit sniffer but was unable to get it to work with the large MTU sizes required by the Brymen meter. If you are aware of how to get this to work, I would appreciate hearing from you.Quote above taken from:https://punchthrough.com/manage-ble-connection/1)Application's sample rate slows down while logging for extended periods2)Phone drops connection at random (not battery, low signal or outside RF interference)3)Unable to reconnect after a connection was made (requires restarting the application)4)Recorded data is 10x higher than actual and outside of meters range *15)If phone powers off due to low battery, data is lost *26)Application hangs when trying to save data*1 Fixed as of 7/11/25*2 I am not sure why they don't ask for the file name first, then stream it to NVRAM rather than keeping the data in RAM

author: joeqsmith
author_rank: Super Contributor
timestamp: July 23, 2025, 01:51:55 pm
content: The following is from Google AI. I assume this is done by the stack.BLE using empty packets as a link detectionUsing empty packets for link detection in Bluetooth Low Energy (BLE)In a BLE connection, devices periodically exchange data. When there's no application data to send, devices transmit "empty packets" to ensure the connection remains active. These empty packets serve as a handshake, and if either device fails to receive a packet from the other within a defined "Supervision Timeout", the connection is deemed lost.Mechanism of empty packets for link detectionPeriodic Transmission: In a BLE connection event, the master and slave devices are required to transmit a packet on each hopped channel. If no data is available to send, these packets become "empty data packets".Connection Events: A BLE connection is maintained through periodic connection events. Each event starts with the master sending a packet, and the slave responding.Keep-Alive Function: If there's no application data to be sent, the devices exchange mandatory empty packets to keep the connection alive.Supervision Timeout: Both the master and slave maintain a "Supervision Timer", which resets upon receiving a link-layer packet. If this timer reaches the configured "Supervision Timeout" (which can range from 100 milliseconds to 32 seconds), the device considers the connection lost and exits the connection state.Why empty packets?Power Efficiency: BLE is designed for low power consumption. Transmitting minimal-sized empty packets (a 16-bit header and a 24-bit CRC) consumes less energy than larger data packets. This allows devices to quickly perform necessary tasks and then disconnect or enter low-power modes, optimizing battery life.Maintaining Connection: Even without active data exchange, the periodic transmission of empty packets ensures the devices remain synchronized and aware of each other's presence, preventing the connection from timing out due to inactivity.In essence, empty packets in BLE act as a heartbeat, ensuring the integrity of the connection without incurring significant power overhead, a crucial aspect for BLE's low-energy design.AI responses may include mistakes. Learn more

author: EEVblog
author_rank: Unknown
timestamp: July 23, 2025, 11:50:24 pm
content: Quote from: joeqsmith on July 23, 2025, 01:45:15 pmThat seems like an obvious change to make. Append CSV file every 100 samples or something.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 24, 2025, 02:07:09 pm
content: Back when I was working with the UNI-T UT181A and 121GW BLE meters, I was using Adafruit's sniffer with NORDIC radio. It worked fine for that but with the new Brymen meter, it seems to have a problem with the large MTU size. A have used both BLE 4.0 and 5.0 to communicate with the Brymen.I purchased Adafruit's latest sniffer and installed all the latest tools (wireshark, python ....). The first thing I ran into was NORDIC phython script fails with syntax problems. Many people have asked about this problem and others have posted how to address it. Doesn't give me a lot of comfort. I patched the script and everything seems to run as normal. Wireshark displays the Advertise packets but as soon as I connect to the meter, it shows no other data. I have all of the decoders active and no filters.When I revert back to the old Wireshark and NORDIC tools, Wireshark captures packets after the connection. They are all just short.Having a sniffer would have been very helpful with this project but the low cost ones may not be up to the task.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 24, 2025, 05:35:44 pm
content: Looks like this one may work. Towards the end of their write up, they are sniffing some packets that are much larger than the Brymen meter uses.https://dojofive.com/blog/using-the-nordic-nrf-sniffer-for-ble/

author: joeqsmith
author_rank: Super Contributor
timestamp: July 25, 2025, 12:04:08 pm
content: Quote from: joeqsmith on July 24, 2025, 02:07:09 pmIt looks like one problem was I had installed the latest Python 3.13.5 and the NORDIC scripts was written for 3.11.x. Installing Python 3.11.9 did allow me to use the script as-is. I also upgraded to wireshark 4.4.8 and WinPcap 4.4.3. Running WS, as before, I see the Brymen advertising but as soon as I connect to the meter using the PC, no further packets are captured.I tried connecting with a cell phone and WS continues to capture packets. It appears that with NORDIC's latter sniffer, there is some sort of conflict when using the same PC to sniff traffic and interface with the meter. Their original software did not work like this. Rather than having to install Python, the provided an EXE ("ble-sniffer_win"). Maybe it did not use the MS stack and that is why the two programs don't interfere with one another.With the changes, I still see the same problem where it doesn't seem to handle the large MTU sizes. I had been using a Targus BU4086 which they claim is BLE 4.0. Most of the on-line documents claim 4.0 did not support the larger MTU size needed. It would require 4.2. I see no difference using a 5.0 and that 4.0 radio with my software. That Adafruit was also 4.0. Not knowing anything about BLE, maybe it was the wild west.I have ordered the NORDIC nRF52840. Part of the reason for wanting to sniff the traffic is to try and understand how Brymen's OTA programmer works. This information was not included in their interface document.

author: Kean
author_rank: Unknown
timestamp: July 25, 2025, 12:23:47 pm
content: Yes, BLE 4.0 had a limited MTU but was not "enforced" so some implementations did allow longer. BLE 4.2 added the data length negotiation to increase MTU.I'm no BLE expert, but I have done some implementation work and researched it a bit. Was using mesh, but have now moved to another mesh protocol.And yes, sometimes installing the latest release of Python will bite you. Been there before - a few times!

author: joeqsmith
author_rank: Super Contributor
timestamp: July 25, 2025, 04:06:41 pm
content: That sure seems like the case (not enforced). I did go through all of that documentation and followed all of the instructions to setup the new software. I did not run into any problems and it seems to all work as expected. I just need the hardware now.I really don't understand why there is a interference problem when running the other setup. It makes me want to try some other tests using speakers, other meters and such. It's hard to believe that especially having two different dongles, that the OS would have any problems.Talking with Brymen about reverse engineering the OTA programming, they have provided me with some clues. It doesn't sound like they would be apposed to adding these details to their document but as it stands, that work was all contracted out. If you download their application, you can now see who the developers are. Basically any communications I have with the developers is through Brymen. I think it would be easier to just sniff the traffic to answer some of the questions I have.I released that first video on Mar 25, 2025, so today marks 4 months. Hopefully they are able to address my other concerns in short order.***There are several videos showing the NORDIC nRF52840 being used as a sniffer. This one demonstrates larger packet sizes. Confidence is going up...https://youtu.be/HeG3ARRm05I?t=776

author: joeqsmith
author_rank: Super Contributor
timestamp: July 26, 2025, 06:44:18 pm
content: Quote from: EEVblog on April 22, 2025, 12:15:42 amLooking at their latest, it seems there are a few where it is not consistent. I have passed these onto Brymen. Should be a minor change.

author: EEVblog
author_rank: Unknown
timestamp: July 27, 2025, 08:10:16 am
content: Quote from: joeqsmith on July 26, 2025, 06:44:18 pmWow, that's odd, I wonder how that happens?

author: joeqsmith
author_rank: Super Contributor
timestamp: July 27, 2025, 02:43:15 pm
content: Quote from: EEVblog on July 27, 2025, 08:10:16 amMy guess is they are focused on the bigger problems right now and may not have a way to automatically run regression tests. It would be easy to check but you may have noticed that when you change the meter's settings while logging data, the application stops collecting and asks if you want to save the data. So you have to create a file for each mode and run through the ranges.If you are asking about how their code is structured that you could change the formatting for some but not all, that's a good question.With the older WireShark/Adafruit sniffer at least being able to capture the empty packets, I thought I would try and see what is going on when the PC is unable to recover after the meter disconnects. Part of the problem with the old NORDIC ble-sniffer software, it can't locate the meter after it has started logging. You can start their software, select the meter then start the logging and then stop Wireshark. Then you can start it back up some time later. The problem is, the NORDIC software is not robust enough to allow me to capture after a day or so. The Brymen meter is turning out to be more reliable. The new NORDIC radio should arrive in a few days.1)Application's sample rate slows down while logging for extended periods2)Phone drops connection at random (not battery, low signal or outside RF interference)3)Unable to reconnect after a connection was made (requires restarting the application)4)Recorded data is 10x higher than actual and outside of meters range *15)If phone powers off due to low battery, data is lost *26)Application hangs when trying to save data7)Cell phone data file format (units after value) is inconsistent in different functions/ranges*1 Fixed as of 7/11/25*2 I am not sure why they don't ask for the file name first, then stream it to NVRAM rather than keeping the data in RAM

author: joeqsmith
author_rank: Super Contributor
timestamp: July 27, 2025, 06:31:44 pm
content: Looking at the mean of the 1k test resistance. Plot showing the drift over a 2 hour period. The modified/poor man aligned BM786 (BT) drifts about 0.03 ohms. That's just sitting on the desk (ceiling fan causing all sort of air currents). Time to pull out the meat packing box and see if we can tighten it up a bit.https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg1371562/#msg1371562

author: joeqsmith
author_rank: Super Contributor
timestamp: July 27, 2025, 10:11:18 pm
content: Looking at the mean 2 hours after the chamber was allowed to stabilize at 21C. About 0.002 ohms of drift.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 30, 2025, 06:54:05 pm
content: The NORDIC radio arrived. Easy enough to program in the firmware and set it up with WireShark. Sniffing traffic at work, I am seeing packets in excess of 200 Bytes, so looks like the MTU problem is solved.***Shown BM786 sending a reading to the cellphone.For $10 USD, I think we have a winner.

author: geralds
author_rank: Contributor
timestamp: August 02, 2025, 12:52:31 pm
content: If of interest (and not sure whether this has been posted before), I just noticed that the BM788BT is now shown on Brymen's website:http://www.brymen.com/PD02BM780_788BT.html

author: joeqsmith
author_rank: Super Contributor
timestamp: August 04, 2025, 08:52:12 pm
content: Brymen's latest is version 1.0.66. The last version I tested was 1.0.64. They do not have a change log, and I have not heard anything from Brymen as far as what was changed or why. I can't see any reason to run these long tests on each release they have without knowing that they have at least attempted to address some of the more major problems.I have spent a few days trying to understand more about the undocumented commands. I used that NORDIC sniffer and Wireshark to record from the time the meter was turned on, to the phone connecting, logging data, then programming the FLASH and back to logging. The sniffer worked very well for this and they made it fairly simple to setup filters in Wireshark to sift through the 10s of thousands of packets. I now have the checksum for the OTA commands working and have some idea how the the programmer works.There are two problems that I ran into. The first is with Windows. Brymen uses a connection interval of 100ms and a supervision timeout of 6000ms (from their document). BLE 101, if there is no data to be transferred, empty packet are sent. If there is no data received for 5 seconds, the meter will close the connection and start to advertise.The problem is with windows/labview, if I close the connection, the OS keeps the port open by continuing to send empty packets. The only way to close the connection is to exit the application, or it's possible to use pnputil. The problem with that is Microsoft did not see fit to allow the full command set for all versions of Windows 10.PNPUTIL [/add-driver <...> | /delete-driver <...> |/export-driver <...> | /enum-drivers |/enum-devices [<...>] | /enum-interfaces [<...>] | /?]Why do I care? One of the modes where the DMM hangs is that it stops sending notifications. It's really a bug with the meter, but Windows could recover if I could reset the driver or get it to stop sending empty packets keeping the connection open. Using Device Manager to reset the driver does indeed recover the communications without resetting the DMM's BLE or Labview.I have started to experiment with some of the undocumented commands. The DMM can get into a state where I flat out can't recover the meter without power cycling the radio (turning BLE off and on). While it is in this mode, it will advertise and I can connect, but the meter will not respond to any of the high level commands. This is after dropping to the boot loader and trying to exit back to the application. In this mode, even with no data being sent to it, it will not recover after the 6second timeout. Their cell phone application behaves the same, locating the meter but unable to connect to it.***Removed all programming notes as to not waste anyone's time chasing bad info

author: joeqsmith
author_rank: Super Contributor
timestamp: August 06, 2025, 12:30:00 pm
content: Quote from: joeqsmith on August 04, 2025, 08:52:12 pmI tried the latest software on two different cell phones with both meters. The UNNECTO stopped logging after 12-20 hours and was prompting to save the data. I selected save and got the spinning icon. I left the phone in this state for about 20 hours and it never changed. It required the application be closed. All data was lost.I manually stopped the Motorola Trac phone after about 30 hours of logging to avoid any problems. I selected save the data and get the same spinning icon for a few minutes then it prompted for a file name (all normal). I selected the default file and again get the spinning icon. It has been in this state for about an hour. Again, all data was lost.Both of these failures, while a little different fall under #6 below. What ever the developers changed, it did not appear to address this major problem.1)Application's sample rate slows down while logging for extended periods2)Phone drops connection at random (not battery, low signal or outside RF interference)3)Unable to reconnect after a connection was made (requires restarting the application)4)Recorded data is 10x higher than actual and outside of meters range *15)If phone powers off due to low battery, data is lost *26)Application hangs when trying to save data7)Cell phone data file format (units after value) is inconsistent in different functions/ranges*1 Fixed as of 7/11/25*2 I am not sure why they don't ask for the file name first, then stream it to NVRAM rather than keeping the data in RAM

author: joeqsmith
author_rank: Super Contributor
timestamp: August 11, 2025, 12:25:03 am
content: A few small updates. It turns out that the Windows "pnputil" was updated on the Pro version on Win 10. I have since upgraded my PC and have added support for to my software to call this command to reset the BLE driver. It works like a charm.I also discovered that the reason the NORDIC sniffer / Wireshark would not log any date when using the same PC to talk with the meter, it seems Wireshark's device must be set to the Brymen first. Doing so, I was able to record large sessions with the PC as well as the cell phones.I finished up adding the OTA firmware programming to my software. It just doesn't work.Comparing Wireshark between the cell phone and PC, it all looks right, but I am obviously missing something.

author: joeqsmith
author_rank: Super Contributor
timestamp: August 15, 2025, 12:07:04 pm
content: I captured a few more data sets with WireShark using the cell phone and the PC. I have compared the packets and everything matches, at least when looking at the application and boot loader commands and their responses. I thought time between packets may have been used as another layer of protection, that or the number of notifications between commands, but coding in similar check yielded nothing. Basically, what happens is all BLE packets appear correct up to the point where I drop to the boot loader and attempt to program the very first locations of memory. Then the meter appears to return an error code.The email address provided in the software download area is not actually for the people developing the software but for Brymen. I have asked Brymen if they would consider putting me in direct contact with the developers to work through these last few problems and help clear up some of the undocumented commands.Even if we are able to sort out the programming, if you run their software and try to update the FLASH, it will prompt you for a local or auto download file. So far, I have not seen the download from the internet work. Brymen has had to supply the updates to me directly. In the future I suspect everything will be over the internet, which will mean sorting out where those files are stored and how to retrieve them.Because of #2, Phone drops connection at random, and I have seen with the PC where the meter gets into a state where it no longer sends notifications, I suspect there will continue to be updates to the firmware, at least in the short term.

author: joeqsmith
author_rank: Super Contributor
timestamp: August 23, 2025, 02:54:01 pm
content: I have removed all of my programming notes as to not waste anyone's time chasing bad info. This morning, I was able to successfully program the meter using my software for the very first time. At this point, I would have settled for bricking the meter.Shown using Motorola cell to verify the version after reprogramming from 1.0.1. Of course, I still do not know what the undocumented commands do. With Brymen's approval, I would like to include these details in the open source documentation.Also shown is the BM786 prototype with added BLE radio. The O-ring is holding the meter together (no screws) to gain access to the programming connector. The hot glued battery pack is also shown.If you need to work with BLE, that $10 NORDIC nRF52840 radio was well worth it.

author: joeqsmith
author_rank: Super Contributor
timestamp: August 26, 2025, 02:05:20 pm
content: I received the following response from Brymen:QuoteThis is very good news for those interested in writing their own custom applications. There are a few details I am trying to resolve with Brymen, including how the firmware will be distributed and descriptions for the extended commands used during programming.

author: joeqsmith
author_rank: Super Contributor
timestamp: August 27, 2025, 05:24:06 pm
content: From Brymen's testing, the cell phone application's automatic firmware update works. They asked how my cell phones behave so I made a video showing all three phones attempting to program a meter. I also demonstrate my custom software programming the meter's BLE to the latest revision. It's a lot faster. Seconds vs minutes.

author: EEVblog
author_rank: Unknown
timestamp: August 28, 2025, 03:45:59 am
content: Remote update doesn't work on mine.Auto download shows network error like yours, and the manual select file displa ythe same as yours and appears to download a chinese character file like your but the file does not show up to select it.Same version 1.0.66

author: joeqsmith
author_rank: Super Contributor
timestamp: August 28, 2025, 01:18:38 pm
content: Quote from: EEVblog on August 28, 2025, 03:45:59 amGood to know. I have passed this onto them. They are working on it.Brymen would need to provide you with the programming file. Copy is to the phone's download area. I tether my test phones to the PC and copy them over.!!!!WARNING!!!!!YOU COULD POTENTIALLY BRICK THE METER!!!! Early on in my testing, Brymen provided a version that required the hardware programmer. Later, I tried to use the phone application to upgrade from a very old version to a much more recent and it bricked the meter's radio. The company doing this work may have changed something in the firmware/application that made these not compatible. With your meter having very old firmware, I suspect you may have a problem if you attempt to load the latest release (1.0.3). I assume now that the meter is for sale to the public, the design is stable and there is no concern.Maybe consider testing with the released meter once they arrive.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 02, 2025, 09:02:39 pm
content: I sent Brymen my first draft of my notes on how to program the FLASH over-the-air.I saw where they have a new protocol interface document available on their website. Hopefully in the future, it will include my notes.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 03, 2025, 02:10:10 pm
content: Brymen has reviewed my OTA document and will append it to their document in the future. Hopefully it provides enough details that someone could write their own custom application from scratch.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 05, 2025, 12:10:27 pm
content: Dave, I understand they are going to release a new application soon that will address the remaining problems. It would be good if you test it as well. Were you able to update your meter's firmware?

author: EEVblog
author_rank: Unknown
timestamp: September 06, 2025, 01:05:49 am
content: Quote from: joeqsmith on September 05, 2025, 12:10:27 pmJust got the email about the new app, haven't tried yet, probably can't do it this weekend.Wasn't able to get the BT module firmware update working.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 06, 2025, 05:43:04 am
content: Unofficial BM78x BLE OTA programming procedure1) Download and install latest 1.0.66 application using the link they provide from their main page2) Copy BM78xBT_1_0_3.cyacd into the cell phone's download directory (file supplied by mfg)3) Turn on meter and enable the BLE4) Start application5) If you wait long enough, the app should start scanning for advertisements from the meter, and locate it5a) You may need to press the + key or toggle the BLE on/off6) Once app detects the meter, just press on the meter that it is showing RSSI7) Enter the password for the meter (0000)App will link with meter and should list the meter with MAC and check mark next to it9) Select the About key10) Select Version Information11) Select BM78xBT (down arrow)12) App will prompt BLE firmware OTA? Select Update13) Select File14) Wait for screen change, Chinese characters, spinning icon. Eventually app will prompt Update OTA Select File(You do not need to select the Reconnect key)15) At this point, you have never used the app so no files will be listed.Press the paperclip key16) App will prompt with Downloads. Select the cyacd you copied into that directory17) App will include selected file in the list. Go ahead and select it by selecting circle to left of file name. Should turn red.18) Select Update19) App will prompt with Preparing to start the update ......20) Now comes the VERY long wait. Very long. Maybe you think the app is hung... Keep waiting.20a) I have seen the application hang here as well as other times. You know the drill, toggle BLE, restart app...21) Eventually the app will start the update and show the % completer. Wait another 5-6 minutes, it should finish at 100%22) App will prompt The OTA firmware update via BLE has been successfully completed. Please restart the device.22) Select OK23) App will close (still running in background).24) Toggle the BLE off and on25) Bring app back to foreground and allow it to reconnect to meter26) Select the About, version, .... to verify that the meter reports the new BLE versionWhat happened when you tried the update? Did you miss the paper clip? I did.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 08, 2025, 04:10:18 pm
content: Just checked and the new software is now available. Looks like they have not yet appended my notes on programming the FLASH.I'll setup a few tests later today. Hoping they now stream that data. Last time I ran it, I once again lost all of my data.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 09, 2025, 12:19:44 am
content: Appears the new cell phone application can download the programming files. The first time I tried it, it failed. The second attempt, it downloaded the file and updated the meter correctly.There is no change log, so I really have no idea what was changed. I can tell you that when I started the log, it still does not ask for a file. They continue to try and collect the data in RAM rather than steaming it to NVRAM. I'll let it run overnight and see if I can get it to save the data without loosing it.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 09, 2025, 04:15:03 pm
content: Batteries failed in the one meter over night causing a disconnect. Oddly enough, the software actually saved the data.I went ahead and installed a fresh set of AAs into my hacked battery holder. Time for some extended testing. The other meter/phone continues to run. Odd, when I restarted the second meter I noticed that the other phone has not slowed down at all. After 12 hours, I would normally notice it.I'll continue letting these run for the remainder of the week and report back, but it does appear they have made some improvements.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 09, 2025, 04:31:21 pm
content: Funny, just noticed Brymen provide me with a change log for their latest software. It appears they have addressed all my concerns. I'll post an update at the end of the week. If I don't loose any data, that's going to be a huge deal!!Graphic Display SmoothnessImproved UI performance by displaying one page at a time without retrospective rendering to prevent overload. The application's sampling rate remains unchanged, even during extended logging periods.BLE Connection StabilityResolved an issue with BLE disconnections by debugging a low-level infinite loop in the BLE communication layer.Reconnection ReliabilityImproved reconnection behavior by addressing the same low-level BLE loop issue as above.Real-Time Logging and Data SavingEach reading is now written directly to the database immediately upon receipt from the meter, without using RAM buffering. This enhances both performance and reliability.Data Loss PreventionAs readings are saved directly to the database file in real time, data remains intact even if the phone powers off unexpectedly during logging. Data loss is effectivelyprevented.Data Saving CompletionData saving now completes automatically once logging ends. No additional processing is required afterward.CSV File Format ConsistencyImproved consistency in the CSV data file format for better compatibility and ease of use.

author: EEVblog
author_rank: Unknown
timestamp: September 10, 2025, 02:48:05 am
content: Quote from: joeqsmith on September 09, 2025, 04:31:21 pmThose are huge updates, will try it today.

author: EEVblog
author_rank: Unknown
timestamp: September 10, 2025, 04:48:27 am
content: My android app is now 1.0.70 but it no longer connects at all.The apple app hasn't updated from 1.0.64 yet, but it still connects within seconds.Something is up...

author: joeqsmith
author_rank: Super Contributor
timestamp: September 10, 2025, 06:03:41 am
content: Quote from: EEVblog on September 10, 2025, 04:48:27 amWere you able to update your meter to the latest firmware for both the radio and meter first? Does the app detect the meter advertising? Does it hang during the connection phase (where you see the %)?I am testing with the Motorola and BLU phones as these were the most problematic in the past. Both meters have the latest updates. Both phones should also have the latest Android updates. I've not had any problems connecting.***If you are not able to update the firmware following my previous instructions, at what step did you run into problems?Also, if you provide the current firmware revisions, I may be able to downgrade my meter and see if I can replicate what you are seeing and maybe find a work around for updating yours.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 10, 2025, 04:27:57 pm
content: Brymen has provided details on how their application obtains the CYACD files. I plan to add this to my custom software. I tried a quick test from where I work but FortiGuard blocks them. One advantage to using your own cell phone provider over a corporate LAN.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 14, 2025, 04:02:21 pm
content: 1)Application's sample rate slows down while logging for extended periods*32)Phone drops connection at random (not battery, low signal or outside RF interference)3)Unable to reconnect after a connection was made (requires restarting the application)*34)Recorded data is 10x higher than actual and outside of meters range*15)If phone powers off due to low battery, data is lost*26)Application hangs when trying to save data*37)Cell phone data file format (units after value) is inconsistent in different functions/ranges*3Cell phone will not connect to DMM*1 Fixed as of 7/11/25*2 I am not sure why they don't ask for the file name first, then stream it to NVRAM rather than keeping the data in RAM*3 Fixed as of 9/8/25One feature I have asked them for is a way to flush the database. During this extended testing, I have ran into various problems but I had no data loss!!!While I am not sure what version of firmware is in Dave's meter, it appears that while my Motorola and BLU phones connect, the UNNECTO no longer will. During the scan process, it never sees the DMM advertising. I have made Brymen aware of this.Brymen was also able to replicate problem #2. They believe that notifications and not being received and this seems to be what I am seeing as well when running my custom application.I have added support to my software to download the CYACD files from their site. Works like a charm. Because corporations may block this service, Brymen will provide a direct link allowing customers to manually download the files.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 16, 2025, 03:05:24 pm
content: Brymen had asked about using WireShark to see what was going on at the time the phone stops logging. This was the first time I have ever attempted to run WireShark with that NORDIC radio for an extended time. WireShark allows you to run in a mode where the display is not updated to ease the burden but because it can be a bit hit and miss getting it to track the meter, I keep the display active to monitor the traffic.Surprisingly, it actually collected the entire set of data, from advertising, to logging on and sending the password, till the phone stopped updating. Luckly, it didn't take long. About 15 hours of data. At 5Hz, that's not too bad. 260,000 samples. But consider that BLE is actually sending data much faster. We end up with 3,616,815 packets. Most of them empty. That's a lot of data for WireShark to crunch but it worked!I have sent everything to Brymen. Hopefully they are able to solve why Dave's phone along with my UNNECTO will no longer connect, along with this one last problem. I think once those two are solved, the rest is just fluff.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 17, 2025, 01:32:27 pm
content: QuoteBrymen explained how once you select "files", you can slide each log file to the right. It will then prompt you if you want to delete it. I tried it and it works great. I'm sure the kids would have figured this out in seconds!

author: joeqsmith
author_rank: Super Contributor
timestamp: September 18, 2025, 02:16:33 pm
content: Brymen tested their UNNECTO Bolt 10 and had no problems connecting. I tried mine again, letting it sit in the scan mode for at least a minute, and it would not detect the meter. Looking a second time at the phone settings, BLE is enabled. This time I toggled it off and on. Sure enough, the phone starts seeing the meter and connects to it.I'm not impressed with these cell phones and don't see the attraction for using them with test equipment as they seem so unpredictable. That's not Brymen's problem.So the only major problem is just the meters appearing to randomly stop sending notifications. I looked at the log files today and I have several that ran for over three days. Normally the meter appears to hang before 24 hours. I was not taking notes as to why each stopped logging. Meter and phone battery life was certainly a problem and why I hacked up that 3X AA battery pack. I have asked Brymen to supply me with the older firmware so I can attempt to track down when this problem showed up.My software tracks the time between notifications and plotting this data, there was a change between 1.0.1 and 1.0.2 that looks like they tried to improve the transfer speed as the last two revisions are more stable.***spelling

author: EEVblog
author_rank: Unknown
timestamp: September 19, 2025, 08:53:18 am
content: Brymen are sending me a new bluetooth module with the new version, should arrive monday.New apple app seems to work great.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 19, 2025, 12:20:34 pm
content: When you get the new radio, if the Android phone will still not connect, try the following:If the phone doesn't see the meter during the scanning process, cycle the BLE radio off/on. If that doesn't work cycle the phone's BLE radio in the utility menu.If the phone sees the meter but will not link, on the Devices menu, highlight the BM78xBT. Select the three vertical dots to the right of the Setting. Select Remove the device, and try to reconnect.

author: EEVblog
author_rank: Unknown
timestamp: September 20, 2025, 01:01:42 am
content: iPhone app does not create blank (NaN) time stamped reading when you walk out of the bluetooth range, I'm pretty sure it used to do that?What is does now is it just pauses the live graph continues with the next 0.2sec timestamp as if nothing happened once the packets start coming in again. So you end up with a distorted waveform rather than a waveform with missing data as a true time stamped data logger graph would show.This means you have to make sure you have to plot the X axis based on the actual time stamp, which is correct.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 20, 2025, 04:39:27 pm
content: Quote from: EEVblog on September 20, 2025, 01:01:42 amFrom my experience the first version would blank the screen and loose all the data.

author: EEVblog
author_rank: Unknown
timestamp: September 22, 2025, 06:34:57 am
content: New BLE module installed.Didn't work at first, needed to add a new meter. I think that was the problem before on the android when the app was updated.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 22, 2025, 12:11:02 pm
content: Video is misleading stating all known problems have been corrected.It appears that the meter will stop sending notifications after some random amount of time. While logging with the phone application, the graph will stop updating. This is the last major problem I am aware of and Brymen is working on it. This is a problem with the meter's firmware, not the phone's application. I expect there to be a 1.0.4 soon, or they may try to do something similar to work around it in software like I did with Windows.If you had left the other radio in the list and plug the other radio back in, the software may not scan through the known addresses to find the other radio. I've tried this with two meters sitting side by side with the phone. I think there is a problem but guessing very few people will run into it which is why it never made my list.

author: EEVblog
author_rank: Unknown
timestamp: September 23, 2025, 10:35:46 am
content: Quote from: joeqsmith on September 22, 2025, 12:11:02 pmI've never seen that.Having said that I had it logging all day today on the iPhone and only just now did the waveform freeze. Went to check the meter and it was turned off for some reason. Doesn't seem to be low battery. I simply turned the meter back on, turned data back on the the app just resumed logging.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 23, 2025, 11:06:07 am
content: Today, Brymen provided 1.0.4 to address that problem. I plan to set it up with the latest application and will let it run for the remainder of the week.I frequently saw where after the meter powered off, when I turned it back on it shows good battery. The meter would shut back off shortly after BLE was re-enabled. There is a reason I cobbled up that 3XAA battery pack for these longer tests. If you plan to run a long term test, it is best you start with a fresh set to avoid loosing that data. I think the meter had to run continuously to observe that fault.***Also, you should now be able to update yours using the OTA feature of the phone once they make that firmware available to the public (currently not available).***Updated both meters, using my custom software. No problems there. Went to update the phone applications and batteries were dead. I think the phones wake up from time to time. I will have them stacked on top of one another on the bench and three times now I have found them on the floor. Like the vibrators turn on for the fun of it...Was able to get them charged enough to turn on and update the application. These tests are long enough that I have to leave them plugged in for the duration anyway. Trying the new economy mode that Dave shows. Supposed to consume less power. This may help as I have had the phones run out of power before on these long tests, even when plugged into their chargers.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 24, 2025, 02:01:30 pm
content: Both setups have been collecting data for 26 hours now without seeing the notification fault. Typically one of them would have failed by now, so my confidence is growing in these latest updates.

author: EEVblog
author_rank: Unknown
timestamp: September 24, 2025, 11:40:31 pm
content: Quote from: EEVblog on September 23, 2025, 10:35:46 amCorrection, it was the battery. The Bluetooth transmit pulses can cause a low battery event and hence meter shutdown in data logging mode, without registering low battery in non-logging mode. Not surprising when you have rising battery ESR at end of life.

author: EEVblog
author_rank: Unknown
timestamp: September 24, 2025, 11:43:38 pm
content: Quote from: joeqsmith on September 23, 2025, 11:06:07 amExplains why I have never seen it. All my tests have been within the time limits of the standard battery pack.I wouldn't be concerned about such an issue at all, as this isn't designed as a really long term data logger solution.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 25, 2025, 12:25:07 am
content: I've seen it with a new set of batteries loaded in the standard pack. I think the shortest time I had it run and saw the notification fault was maybe 5 hours. Typical was maybe 24 hours. The last time when I used WireShark to log it, was 15 hours.Currently at 36 hours run time, no fault. It's looking really good.

author: EEVblog
author_rank: Unknown
timestamp: September 25, 2025, 01:10:50 am
content: Quote from: joeqsmith on September 25, 2025, 12:25:07 amThey specifically said it's a fix, so they must have found the bug.QuoteI'm trying to update mine it to the new version, but my meter refused to connect any more. Resetting password didn't work, I had to remove the device and reconnect.

author: EEVblog
author_rank: Unknown
timestamp: September 25, 2025, 02:16:30 am
content: BLE firmware updated

author: joeqsmith
author_rank: Super Contributor
timestamp: September 25, 2025, 02:51:23 am
content: Quote from: EEVblog on September 25, 2025, 01:10:50 amThey certainly have made an attempt to address it. I'll know more in a few days.Quote from: EEVblog on September 25, 2025, 01:10:50 amAs previously mentioned to you...

author: joeqsmith
author_rank: Super Contributor
timestamp: September 25, 2025, 03:06:55 am
content: I watched your video. It's basically what I have seen. Takes a fair amount of time to update the meter. I suspect this is due to the application using a small MTU size when talking with the boot loader. Windows will take full advantage of the larger size. So it's sending less packet with a larger payload. Of course, it also completes in a few seconds. Lucky for customers, this isn't something they will need to do very often. If 1.0.4 does address the notification error, I am not aware of any other problems with the meter's firmware.

author: EEVblog
author_rank: Unknown
timestamp: September 25, 2025, 04:08:29 am
content: On android it does seems to take longer to connect now that it did before. Like 13-15 seconds vs 4-5 seconds.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 25, 2025, 05:49:14 am
content: After several updates, mine were taking about a minute. Brymen suggested that I completely remove the application and reinstall.Just an FYI,I had asked them about a way to manually zoom in on the graph while logging. Because I am running two complete setups, side-by-side, I noticed the meter with the larger signal was zoomed in further than the meter with the smaller signal. They are looking into it but suggested it is automatically scaled only.I have also asked them about creating a getting started manual for the application. It seems self explanatory to me, but I see you stumble on the same problems I have had. It may be helpful to document some of that.I have not heard any more about adding a section to the protocol document covering the OTA. They have my additions and I assume will add them on the next release.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 26, 2025, 01:43:12 pm
content: Just an FYI, the following was my update to Brymen:Quote

author: dpenev
author_rank: Regular Contributor
timestamp: September 27, 2025, 06:27:25 am
content: Hello,Hello apart of the BLE module 1.03 firmware is there another firmware (the main CPU firmware ? ) possible to update in BM788BT ?

author: joeqsmith
author_rank: Super Contributor
timestamp: September 27, 2025, 12:59:44 pm
content: Quote from: dpenev on September 27, 2025, 06:27:25 amYes. But again, the is not available to the public. In other words, you can not update it.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 27, 2025, 01:32:46 pm
content: Testing continues without the notification fault!I had a look at the one CSV file collected when the meter's batteries failed. Their application now keeps up with the meter's sample rate, and because the notification fault seems to be corrected, this is the largest file I have created. Shown below is some of the data from the start, mid and end. I have contacted Brymen about this problem. Once the other tests complete, I can see if this replicates.ï»¿Date,Time,Device,Channel,Function,Reading,offset,offset prefix,Prefix,Unit2025-09-23,19:54:46.084,BM78xBT,#channel1,ACV,0.0058,,,,V2025-09-23,19:54:46.295,BM78xBT,#channel1,ACV,0.0058,,,,V2025-09-23,19:54:46.488,BM78xBT,#channel1,ACV,0.0058,,,,V2025-09-23,19:54:46.685,BM78xBT,#channel1,ACV,0.0058,,,,V2025-09-23,19:54:46.886,BM78xBT,#channel1,ACV,0.0059,,,,V2025-09-26,14:25:26.067,BM78xBT,#channel1,ACV,0.0316,,,,V2025-09-26,14:25:26.264,BM78xBT,#channel1,ACV,0.0316,,,,V2025-09-26,14:25:26.464,BM78xBT,#channel1,ACV,0.0316,,,,V2025-09-26,14:25:26.669,BM78xBT,#channel1,ACV,0.0326,,,,V2025-09-26,14:25:26.865,BM78xBT,#channel1,ACV,0.0325,,,,V2023-02-08,00:00:17.127,BM78xBT,#channel1,ACV,0.0103,,,,V2023-02-08,00:00:17.328,BM78xBT,#channel1,ACV,0.0104,,,,V2023-02-08,00:00:17.532,BM78xBT,#channel1,ACV,0.0104,,,,V2023-02-08,00:00:17.730,BM78xBT,#channel1,ACV,0.0105,,,,V2023-02-08,00:00:17.930,BM78xBT,#channel1,ACV,0.0105,,,,V2023-02-08,00:01:00.299,BM78xBT,#channel1,ACV,0.0029,,,,V2023-02-08,00:00:58.488,BM78xBT,#channel1,ACV,0.0053,,,,V2023-02-08,00:01:00.095,BM78xBT,#channel1,ACV,0.0028,,,,V2023-02-08,00:00:55.677,BM78xBT,#channel1,ACV,0.0058,,,,V

author: joeqsmith
author_rank: Super Contributor
timestamp: September 28, 2025, 02:13:07 pm
content: I had added a more metrics to my software to track the kinds of errors I was seeing. After the upgrade to 1.0.4, I have detected no errors for 48 hours. I am now confident that the problems I was having were a result of that same notification fault.Shown is the time between readings. There was one time where the meter took 1.5 seconds to send the reading. Currently I wait for 4 seconds before I try to recover the data link. Also shown is the previous three revisions.****The other meter with the extended battery pack also ran flawless until I aborted the test today. I am certain Brymen has resolved the notification fault.The second phone was also very slow to link to the meter. Completely removing the application and re-installing once again corrected this. It dropped from about 1 minute to a few seconds.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 28, 2025, 02:52:15 pm
content: Looking at the second CSV file, we can see another problem with the time stamp. I have forwarded this to Brymen. The meter does have a clock function. This bug could be the application or the meter's firmware. It appears to be a simple roll over problem. Nothing else popped out at me.ï»¿Date,Time,Device,Channel,Function,Reading,offset,offset prefix,Prefix,Unit2025-09-25,07:27:16.226,BM78xBT,#channel1,ACV,0.0091,,,,V2025-09-25,07:27:16.441,BM78xBT,#channel1,ACV,0.0091,,,,V2025-09-25,07:27:16.653,BM78xBT,#channel1,ACV,0.0091,,,,V2025-09-25,07:27:16.868,BM78xBT,#channel1,ACV,0.0091,,,,V2025-09-25,07:27:17.080,BM78xBT,#channel1,ACV,0.0091,,,,V2025-09-25,07:27:17.292,BM78xBT,#channel1,ACV,0.0091,,,,V2025-09-25,07:27:17.507,BM78xBT,#channel1,ACV,0.0091,,,,V2025-09-25,07:27:17.727,BM78xBT,#channel1,ACV,0.0091,,,,V2025-09-25,07:27:17.934,BM78xBT,#channel1,ACV,0.0091,,,,V2025-09-25,07:27:18.145,BM78xBT,#channel1,ACV,0.0091,,,,V2025-09-25,07:27:18.361,BM78xBT,#channel1,ACV,0.0091,,,,V2025-09-25,07:27:18.583,BM78xBT,#channel1,ACV,0.0091,,,,V2025-09-25,07:27:18.789,BM78xBT,#channel1,ACV,0.0091,,,,V2025-09-25,07:27:19.999,BM78xBT,#channel1,ACV,0.0091,,,,V2025-09-25,07:27:19.212,BM78xBT,#channel1,ACV,0.0091,,,,V2025-09-25,07:27:19.438,BM78xBT,#channel1,ACV,0.0091,,,,V2025-09-25,07:27:19.639,BM78xBT,#channel1,ACV,0.0091,,,,V2025-09-25,07:27:19.855,BM78xBT,#channel1,ACV,0.0092,,,,V

author: EEVblog
author_rank: Unknown
timestamp: September 29, 2025, 06:41:10 am
content: Quote from: joeqsmith on September 28, 2025, 02:52:15 pmIt doesn't have an RTC.Only way that's possible is if the app pushes the time to the meter CPU. But what would be the reason to do that?

author: joeqsmith
author_rank: Super Contributor
timestamp: September 29, 2025, 10:49:57 am
content: Quote from: EEVblog on September 29, 2025, 06:41:10 amIt certainly does.I assume they reason for it is to know when the meter samples the data which may not be the same time that the remote device receives it.

author: EEVblog
author_rank: Unknown
timestamp: September 29, 2025, 11:07:22 am
content: Quote from: joeqsmith on September 29, 2025, 10:49:57 amThere is no battery backed RTC. Like I said, if they are doing this then they must be updating an internal counter/clock when they initialise the connection. But even then if you turn it off and back on then any clock it did set is gone.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 29, 2025, 11:36:33 am
content: Quote from: EEVblog on September 29, 2025, 11:07:22 amCorrect, they do not have a battery but do have a RTC. The RTC is defined in the interface document you had uploaded a few month ago.I am not aware of any documentation that explains how their application tracks the time. It would make more sense that the meter's RTC reset than the phone's. It happened towards the end of the log, when the batteries were starting to fail. Assuming they are using the meter's BLE module for their timestamp, we may see a 1.0.5 soon.The rollover error I mentioned follows the same pattern (below).2025-09-26,21:22:17.573,BM78xBT,#channel1,ACV,0.0087,,,,V2025-09-26,21:22:17.785,BM78xBT,#channel1,ACV,0.0086,,,,V2025-09-26,21:22:18.999,BM78xBT,#channel1,ACV,0.0086,,,,V2025-09-26,21:22:18.212,BM78xBT,#channel1,ACV,0.0086,,,,V2025-09-26,21:22:18.427,BM78xBT,#channel1,ACV,0.0086,,,,V2025-09-28,03:30:40.573,BM78xBT,#channel1,ACV,0.0087,,,,V2025-09-28,03:30:40.785,BM78xBT,#channel1,ACV,0.0087,,,,V2025-09-28,03:30:41.999,BM78xBT,#channel1,ACV,0.0087,,,,V2025-09-28,03:30:41.212,BM78xBT,#channel1,ACV,0.0087,,,,V2025-09-28,03:30:41.426,BM78xBT,#channel1,ACV,0.0087,,,,VI suspected when they get a 0.999, it is always off by 1 second, but looking at the CSV file, this is not always the case. Some sort of race condition in their firmware? We will see what Brymen finds out.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 29, 2025, 12:25:03 pm
content: Looking at other faults, they do not always happen at 0.999. I really doubt this is a cell phone get time problem but something in the meter's BLE firmware.2025-09-25,11:52:01.231,BM78xBT,#channel1,ACV,0.0149,,,,V2025-09-25,11:52:01.833,BM78xBT,#channel1,ACV,0.0147,,,,V2025-09-25,11:52:00.833,BM78xBT,#channel1,ACV,0.015,,,,V2025-09-25,11:52:01.030,BM78xBT,#channel1,ACV,0.015,,,,V2025-09-25,11:52:02.238,BM78xBT,#channel1,ACV,0.0146,,,,VShown plots are the time between packets for the meter that dropped out first. Note that it was stable for about 40 hours. The rollovers then start to happen more frequent. If I zoom into the first fault, you can see that is not a single event but several.Plotting the voltage readings, we can also see how the ACV is effected as the batteries weaken. I want to be clear that nothing was attached to the meter. The point is that the rollovers don't seem to effect the data being collected.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 29, 2025, 06:27:42 pm
content: Looking at their protocol document, the meter's RTC does not appear to support ms. It's possible the document is not up to date, or they are not using it. My software doesn't use it but it would be easy enough to add. This would at least tell us if the document is correct.***The meter's built in RTC does support ms. I have added support for it, and it matches with the manual. So, depending how they implemented the time stamp, the problem could very well be the meter's RTC clock function.

author: EEVblog
author_rank: Unknown
timestamp: September 30, 2025, 12:15:44 am
content: Quote from: joeqsmith on September 29, 2025, 11:36:33 amYes, I doubt they do this in the meter's microcontroller.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 30, 2025, 01:31:54 am
content: I doubt it too.I have added a check to my software to detect this error, and have changed my CSV file format to match Brymen's. The plan is to run it overnight and see if I detect the fault.***From my previous post where the RTC reset:2023-02-08,00:01:00.299,BM78xBT,#channel1,ACV,0.0029,,,,V2023-02-08,00:00:58.488,BM78xBT,#channel1,ACV,0.0053,,,,VNote that I did not set the RTC prior to starting this test and how it defaults to what was captured by the phone. I am now certain they are using the meter's RTC for the timestamp and this is where at least that clock reset problem resides. Hopefully we can repeat that roll over problem as well.I am not sure what they can do about the low battery resetting the BLE and not the meter (assuming that is what is happening).

author: EEVblog
author_rank: Unknown
timestamp: September 30, 2025, 04:58:39 am
content: Quote from: joeqsmith on September 30, 2025, 01:31:54 amMaybe nothing.Again, this isn't really designed as a robust long term data logging solution, no Bluetooth enabled system is really, you have to have local storage.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 30, 2025, 12:41:52 pm
content: Bymen responded about my latest findings and confirmed they use the meter's built in RTC. We should have an updated application, and BLE firmware to address the roll over problems (apparently there are two different issues).Quote from: EEVblog on September 30, 2025, 04:58:39 amTo me, long term suggests months, years. I think it is reasonable that it can log until the batteries are depleted, which varies depending on the cells used. I leave the cell phones plugged into their chargers for these long tests and even then, their batteries would sometimes fail. Using that ECO mode appears to have solved that.Brymen is planning to release an extended battery pack for this meter. This is a long way out as it will need safety approvals. I have not asked if they are planning to use the triple AA cells like my modified pack, or something else.

author: EEVblog
author_rank: Unknown
timestamp: October 01, 2025, 04:22:43 am
content: FYI: My units will be shipping on Oct 8th.

author: joeqsmith
author_rank: Super Contributor
timestamp: October 01, 2025, 05:09:29 am
content: At this stage, it seems like a safe bet. The only issue I am aware of is the time stamp, and with customer's being able to perform the update, I wouldn't call that a show stopper.I have not asked them about an application for the PC but I thought in your early video that they are planning on having something. Have they provided you with any time frame?

author: EEVblog
author_rank: Unknown
timestamp: October 01, 2025, 05:19:04 am
content: Quote from: joeqsmith on October 01, 2025, 05:09:29 amThey said a while back that they'd start on that after the mobile app.

author: joeqsmith
author_rank: Super Contributor
timestamp: October 01, 2025, 01:23:41 pm
content: They made their mobile app available to publicly download some time ago. Maybe they have started working on it.I asked HKJ about supporting it with their app. It seems they do not have support for BLE devices and it may be difficult to add.https://www.eevblog.com/forum/testgear/program-that-can-log-from-many-multimeters/msg6043141/#msg6043141

author: joeqsmith
author_rank: Super Contributor
timestamp: October 01, 2025, 03:40:37 pm
content: If interested, I could make my test program available. It should run on any PC with BLE.I would need to do something with the CSV file. Maybe use a semicolon rather than a comma to allow the comma for the decimal separator in places like Germany. I wonder how their application handles regional settings.Reviewing my notes, it seems that in countries where they use the comma rather than the period, they did not want me to use that same notation when saving data to a file. In that case, they want the period for the decimal point because other software they use to process the data doesn't handle the comma.So, the phone app should be fine. It would be an easy change with my software to support it.You would need to download and setup the LabView runtime engine and VISA but that shouldn't be a problem. Of course, like most of my software, it's not a polished application meant for the masses but rather something I put together to prove out their interface document and test the meter.

author: joeqsmith
author_rank: Super Contributor
timestamp: October 02, 2025, 12:19:01 pm
content: Brymen has provided me with BLE firmware 1.0.5 to correct one of the RTC problems. I may hold off on any long term testing until we have the updated application.Quote from: joeqsmith on September 29, 2025, 10:49:57 amI have added ability to plot the time between packet using both the PC and DMM's RTC values. These are on the same vertical scale. Note how much tighter the DMM is. I am not sure what causes such a major error with the PC.My guess is Brymen knew there are customers who want that sample time as accurate as possible.

author: joeqsmith
author_rank: Super Contributor
timestamp: October 03, 2025, 09:06:05 pm
content: I updated both meters to the latest 1.0.5 BLE firmware using my software, and ran one of them for a day. I saw no problems with the time stamp.Once they update the application, I plan to run another several day test using both meters with cell phones rather than the PC.When I first tried this meter with a cell phone, I was lucky to get it to connect. If it connected, I was lucky to collect a few minutes of data. If it did collect the data, I was lucky if it would save it. Now days, I don't even bat an eye when collecting 24 hours of data. They have really done a nice job addressing the issues.

author: EEVblog
author_rank: Unknown
timestamp: October 04, 2025, 04:51:07 am
content: Quote from: joeqsmith on October 03, 2025, 09:06:05 pmI've also updated to 1.0.5 no problems.

author: EEVblog
author_rank: Unknown
timestamp: October 09, 2025, 11:14:19 pm
content: Stock just turned up. So much doing a video today, I'll have to get this on the store.

author: EEVblog
author_rank: Unknown
timestamp: October 09, 2025, 11:36:31 pm
content: Dual meter display works in the Dashboard screen, and dual logging as well, not on the same graph though, it adds a 2nd logging graph below it.

author: EEVblog
author_rank: Unknown
timestamp: October 10, 2025, 04:26:30 am
content: It's now on my store for order."orderofmagnitude" for 10% offhttps://eevblog.store/products/eevblog-bm787bt-bluetooth-multimeter

author: joeqsmith
author_rank: Super Contributor
timestamp: October 10, 2025, 03:56:38 pm
content: Are you planning to make some sort of mini review now that the software is basically working?Beyond just your basic Dave tests, consider showing:Logging data, exporting, file format....Running two or more meters, showing CSV files...How to update firmwareTroubleshooting connection problemsAny differences between the Apple and Android

author: BILLPOD
author_rank: Frequent Contributor
timestamp: October 10, 2025, 07:30:42 pm
content: Quote from: EEVblog on October 10, 2025, 04:26:30 amThanks a lot, Dave. Now I've got to think of a good excuse why I need another DMM. I may have to wait until Christmas time and get it for my wife, who won't use it, so I'll just 'borrow' it from her.I hope you have some stock left by then.

author: EEVblog
author_rank: Unknown
timestamp: October 10, 2025, 11:32:20 pm
content: Quote from: BILLPOD on October 10, 2025, 07:30:42 pmThey aren't exactly flying off the shelves. It's the most expensive meter I sell, FOB cost is above the 121GW.

author: papabol_24
author_rank: Contributor
timestamp: October 11, 2025, 04:24:49 am
content: Hello Dave, since your using DHL, maybe you could consider shipping to Saudi Arabia... Thanks

author: BILLPOD
author_rank: Frequent Contributor
timestamp: October 11, 2025, 08:00:42 pm
content: Quote from: EEVblog on October 10, 2025, 11:32:20 pmI've had the 121GW for several years, and I LOVE it, because it has features that can't be found on any other meter that I know of. But this BM787BT is calling my name, (don't tell SWIMBO).

author: jasonb
author_rank: Newbie
timestamp: October 12, 2025, 01:14:46 am
content: I can't seem to ship this to the US or Canada because it says it's not available in those locations. Any idea when it'll be available to ship to North America?

author: EEVblog
author_rank: Unknown
timestamp: October 13, 2025, 02:47:39 am
content: Quote from: jasonb on October 12, 2025, 01:14:46 amOops, Shopify sucks. Fixed.

author: EEVblog
author_rank: Unknown
timestamp: October 13, 2025, 02:52:27 am
content: Quote from: papabol_24 on October 11, 2025, 04:24:49 amThat is in DHL Zone 6, it's a big price jump, so I don't offer it.

author: MathWizard
author_rank: Super Contributor
timestamp: October 14, 2025, 04:28:53 am
content: I never tried the infrared com port on my Brymen DMM, did anyone try making their own wireless adapter for any of these ? I might try doing it on my own, I have an MP3 player w/ BT, that I will retire soon, and I wonder how hard it would be, to hack/mod something with it ??If all that is too hard, then I'd just buy some ready-to-go BT unit, and make an interface or program some MCU, to go between the DMM's infrared COM and the BT unit.

author: mwb1100
author_rank: Frequent Contributor
timestamp: October 14, 2025, 05:33:27 pm
content: Quote from: MathWizard on October 14, 2025, 04:28:53 amWhich Brymen DMM do you have? Getting a BT adapter to work with the meters that use the BU-86X adapter cable (BM86x, BM52x or BM82x) might be a challenge since the cable for those act as a HID device instead of a COM port. But the cables for other meters are just a COM port connection. I believe the IR protocol for those meters has also been reversed (alternate serial adapters have been developed). I don't know if that has happened for the BU-86X adapter.