hybridfree/eevblog-posts huggingface dataset:
rotary encoder - Page 1
Forum section: electronics / projects

author: basantab
author_rank: Contributor
timestamp: October 08, 2018, 05:37:22 pm
content: Hi,I am working on function gen project (sin/sqr/tri) and I have used potentiometer to adjust frequency. At some point i am thinking to replace it with rotary encoder and modifying codes in micro-controller.I went on googling and learned the types of rotary encorders.I found this basic encoders.https://www.sparkfun.com/products/9117and these optical or quardrature encodershttps://www.sparkfun.com/products/11102My question is: what kind of encoders do they use in those big rigol or agilent function generators (or signal generators ) ?(just curious)If someone could paste some link of those i would love to see them. As I do not know what to google on those.thankyou

author: SiliconWizard
author_rank: Super Contributor
timestamp: October 08, 2018, 06:06:02 pm
content: Pretty much the same as your first "basic" encoder. Only higher quality (usually) on high-end gear.This Bourn series was used in some Lecroy scopes for instance:https://www.bourns.com/products/encoders/contacting-encoders/product/ECW
Rotating Work Bench with Power Tools - Page 1
Forum section: electronics / projects

author: jonovid
author_rank: Super Contributor
timestamp: February 05, 2025, 09:34:30 am
content: In one corner of the room I have an old round pedestal kitchen table that I use as a second work bench for my other power tools / RC toy crafting projects.I am considering making the round pedestal table a Rotating work bench using a lazy susan turntable bearing under it.so I can access all sides of the round Work Bench. one consideration I would like to add to it is an AC mains outlet in the centre of the rotating work bench.using a 250 V AC 10Amp 4 ch slip ring - with 4 wires- 2 for grounding , 1 for neutral 1 for active.this extension cord would be cut and the slip ring added to the power cord under the table. in the middle the turntable bearing in-between parcel boardthe slip ring I am considering using is this 10Amp unit -see image

author: Ranayna
author_rank: Super Contributor
timestamp: February 05, 2025, 09:50:04 am
content: How would you fixate that?Most lazy susans i encountered (not many admittedly) are somewhat wobbly, and more importantly, you need a way to reliably stop it from turning when you want to actually use it as a workbench.

author: RoGeorge
author_rank: Super Contributor
timestamp: February 05, 2025, 04:09:20 pm
content: Rotating or not, it will be the same size. To get more working area, sometimes I use layers:https://www.eevblog.com/forum/chat/invention-of-the-day-desktop-save-as-with-jar-instances/

author: weedslipring
author_rank: Newbie
timestamp: March 12, 2025, 05:34:37 am
content: Hi ,for Rotating work running stable ,you must use safely flange slip ring ,control the speed to be stable,maybe you can reference model [SPAM LINK REMOVED],you can check more detail ,hope can help you ,thank you

author: jpanhalt
author_rank: Super Contributor
timestamp: March 12, 2025, 01:26:31 pm
content: I am reminded of the saying, "Just because it can be done, doesn't mean it should be." The reason you can't work on the backside of that workbench is not that it doesn't rotate.Your bench doesn't look a lot different than mine, when I am not expecting company.
Roughly dropping voltage to charger IC - Page 1
Forum section: electronics / projects

author: CheekyRobot
author_rank: Contributor
timestamp: July 09, 2015, 03:05:25 pm
content: I need to charge a 1cell 2000mAh Lipo on my device. Normally, it's strapped to a vehicle and can keep itself topped up using the vehicle's battery and I'd like to be able to charge it via a USB charger when it's taken off.I might use something like a MAX1551http://www.farnell.com/datasheets/1675715.pdfIt gives me a dual input from USB as well as an ac adapter input which I could connect to the vehicle's 12v battery to keep the LiPo topped up.Now... what this question is about is whether it's a better idea to just use a resistor to drop the 12v input from the vehicle's battery to the 4-7v that the charger IC would like (23r ish at 1.8w if I'm drawing the 300mA that the datasheet suggests) or to pop in a regulator. I'm a little loathed to use a 7805 or similar given how inefficient linear regulators are or should I go all fancy and put in a buck regulator? (expensive?).The device itself only draws about 200mA absolute max spike current, so we're not really pushing a lot of power about here.Any thoughts or suggestions?

author: Zero999
author_rank: Super Contributor
timestamp: July 09, 2015, 03:11:47 pm
content: If you want cheap and cheerful, you could use a Black regulator:http://www.romanblack.com/smps/smps.htm

author: CheekyRobot
author_rank: Contributor
timestamp: July 09, 2015, 03:33:20 pm
content: Quote from: Hero999 on July 09, 2015, 03:11:47 pmCute! Though that big-old inductor is gonna kill me. This all fits into a VERY small box
Round eink / epaper displays - Page 1
Forum section: electronics / projects

author: pinkunicorn
author_rank: Newbie
timestamp: March 20, 2018, 12:53:43 pm
content: Hey GuysDoes anyone know where to get colour eink / epaper displays which are round?ThanksP

author: mark03
author_rank: Frequent Contributor
timestamp: March 20, 2018, 04:51:45 pm
content: JDI (Japan Display) makes one. Technically it is an LCD, but designed to be used in ambient light. A useful search phrase is MIP (Memory In Pixel) technology.As for how to obtain them... Good luck!! "Contact your distributor" etc. etc. etc.

author: Mr. Scram
author_rank: Super Contributor
timestamp: March 20, 2018, 05:15:20 pm
content: These people have one.https://shopkits.eink.com/
Routaboard prototyping PCB - Page 1
Forum section: electronics / projects

author: knivd
author_rank: Newbie
timestamp: May 26, 2016, 08:29:49 pm
content: Wanted to share this link:http://routaboard.com/It is a new type of prototyping PCB

author: Gyro
author_rank: Super Contributor
timestamp: May 26, 2016, 08:40:09 pm
content: Hmmm, that looks pretty confusing to configure. A proto board that needs software to tell you how to solder the connections?

author: knivd
author_rank: Newbie
timestamp: May 26, 2016, 08:42:01 pm
content: Haha, no you don't need the software. It is only to make life easier.

author: Gyro
author_rank: Super Contributor
timestamp: May 26, 2016, 08:45:02 pm
content: Ok, software tohelpyou configure it (before you go blind)

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 26, 2016, 08:51:24 pm
content: Interesting idea. Not ready for use yet. The software does nothing at current version. If the software is wonderful it may make this a good idea, but that seems to me would be comparable in scope to writing a full fledged EDA package. I am also concerned about the potentially large number of solder bridges required to do anything of meaningful size. Probably faster and easier to order a custom board.

author: Gyro
author_rank: Super Contributor
timestamp: May 26, 2016, 09:01:11 pm
content: I can't see an actual photo - maybe if the board was selectively solder-masked and plated so that just the holes and links were solderable.It also seems to be very selectively routed in one diagonal axis, nothing for the other axis unless you waste a lot of holes. I think if I was designing something like this I might just go for a set of horizontal tracks passing between the holes that could be linked to adjacent ones; a bit like Veroboard but with tracks passing between pads rather than though them. Again it would have a problem with scale and clearances without a solder mask. The main point about 0.1" matrix board is that it's for through hole parts and easy to hard-wire.
Route a SMD crystal with four pads - Page 1
Forum section: electronics / projects

author: metRo_
author_rank: Regular Contributor
timestamp: April 29, 2014, 03:11:28 pm
content: Hi allI'm routing a PCB that and because the cost and other parameters I selected the following crystalhttp://www.mouser.com/ds/2/137/FA-238_238V_TSX-3225_E09X-8063.pdfI want to ask you if it is ok if the tracks from the microcontroller to the crystal have diferent lengths like below:And it is ok if I need to use vias?Thank you

author: Kjelt
author_rank: Super Contributor
timestamp: April 29, 2014, 04:17:04 pm
content: Wouldn,t do it, just rotate it 90 degrees and you are fine.

author: Dago
author_rank: Frequent Contributor
timestamp: April 29, 2014, 05:04:57 pm
content: Doesn't matter.

author: zapta
author_rank: Super Contributor
timestamp: April 29, 2014, 05:35:00 pm
content: You can see an example herehttps://github.com/zapta/power-monitors/blob/master/pmon_uno/eagle/pmon_uno_top.pdf?raw=true

author: metRo_
author_rank: Regular Contributor
timestamp: April 30, 2014, 09:58:41 am
content: Thank you allDid it like that:

author: ConKbot
author_rank: Super Contributor
timestamp: April 30, 2014, 11:04:37 am
content: Just keep the ground traces tidy too, preferably running to the same gnd that the micro is using to keep the loop area small, and minimize emissions from that.Or dont, one of our MEs did a board with a uC on it and a crystal where the ground traces ran ~2" away, separately, going to a ground pin on the far side of the board, with no ground plane, and everything still worked. Just hope there were no ham operators running in the 20MHz (or harmonics of that) nearby, especially when we had ~30 units going at once.
Router Monitor using Arduino ?? - Page 1
Forum section: electronics / projects

author: Swaroop 21
author_rank: Regular Contributor
timestamp: May 11, 2025, 01:57:21 pm
content: I want to display the routers UP-TIME, and Devices connected etc or whatever I can extract from it. Is there any way to get this data from the Routers IP addr (192.168.0.1) its a TP-LINK WR840N. Get the data and stats from the router using a python script maybe ? but how do I exactly extract the data from that IP ?

author: eutectique
author_rank: Frequent Contributor
timestamp: May 12, 2025, 12:11:04 pm
content: Your router might have a web page with network topology and system statistics. Write a script to get the relevant pages from the router's web UI, parse the result, you are done.

author: fchk
author_rank: Frequent Contributor
timestamp: May 12, 2025, 12:18:12 pm
content: Quote from: Swaroop 21 on May 11, 2025, 01:57:21 pmGood/professional routers and switches support SNMP for management and mean for the thing you intend to do.Cheap ones don't - here you need to fall back to web-scraping, which can be very complicated if the UI uses Javascript.

author: tunk
author_rank: Super Contributor
timestamp: May 12, 2025, 12:40:24 pm
content: I guess you also have to find a way to log into it from yourarduino code. And an Arduino Uno may not have enoughram and flash (an ESP32 may have). The Raspberry PiPico can be programmed in MicroPython.

author: voltsandjolts
author_rank: Unknown
timestamp: May 12, 2025, 01:17:58 pm
content: The manual for the OP's router doesn't mention snmp unfortunately.Also, while it issupportedby OpenWRT, the 8MB/64MB of flash/ram is limiting,newer more secure versions need more.
Routes to wireless video? - Page 1
Forum section: electronics / projects

author: i_am_fubar
author_rank: Regular Contributor
timestamp: January 26, 2020, 06:20:51 pm
content: Want to send video (one way) and serial data (both ways) range not too important, nor is video quality.Size is critical.First thought was a 5.8Ghz transmitter and a BT module. But not elegant.Raspberry pi with camera and WiFi. Better, but even a pi zero or compute is bigger than I want.Would ideally like to be able to rotate video 180 degrees, but not essential.Are there any COTS chips that could do this? Or am I very much into an OS on an embedded Linux platform form? If so, what's the smallest chip set I can go for.

author: NiHaoMike
author_rank: Super Contributor
timestamp: January 27, 2020, 02:59:30 am
content: Is ESP32 camera small enough for you?

author: james_s
author_rank: Super Contributor
timestamp: January 27, 2020, 03:17:15 am
content: Is analog video ok? Transmitters and receivers for FPV flying models are dirt cheap. Analog still rules there because digital results in unacceptable lag.

author: i_am_fubar
author_rank: Regular Contributor
timestamp: January 27, 2020, 08:04:38 am
content: I've done some work with an ESP, though just as a Wifi Link.Looks like a good solution, what kind of latency would the ESP have?Analogue is ok, providing the module is small enough. Was looking at the Airwave 5.8GHz modules.This one is SMT and 15x13mm squarehttps://www.airwave.com.tw/en/product-441203/5-8GHz-RF-Modules-AWM669V-TX.htmlCheers.
Routing Equipment Clock Signal Component Failing - Page 1
Forum section: electronics / projects

author: d-chord
author_rank: Contributor
timestamp: February 16, 2017, 05:38:41 am
content: There is a story going around about various routers (and some other equipment) that is being hit by an issue with a clock component which degrades over a period of about 18 months:http://www.networkworld.com/article/3170065/router/juniper-facing-fatal-clock-flaw-that-impacts-cisco-routers-switches.htmlI've had to RMA several router cards which haven't been confirmed to be this issue, but I'm guessing may be. What I'm wondering is what sort of component failure could result in a situation like this? A bad run of crystals with leaky cases? My curiosity is piqued.-David

author: calmtron
author_rank: Regular Contributor
timestamp: February 16, 2017, 07:11:50 am
content: It's the Intel Atom C2000 SOC LPC bus clock output that stops working after a while, see Intels errata AVR54:https://www-ssl.intel.com/content/dam/www/public/us/en/documents/specification-updates/atom-c2000-family-spec-update.pdf

author: d-chord
author_rank: Contributor
timestamp: February 16, 2017, 01:56:44 pm
content: I see now. That's mentioned in the article, but I wasn't getting that it was an actual component on those routers.Thanks!-David

author: madires
author_rank: Super Contributor
timestamp: February 16, 2017, 02:11:44 pm
content: https://www.eevblog.com/forum/chat/dying-intel-atom-c2000-processors-take-out-network-equipment/
routing ethernet signals between PHY and MAGJACK - Page 1
Forum section: electronics / projects

author: phil from seattle
author_rank: Super Contributor
timestamp: May 19, 2020, 03:42:23 am
content: One of the rules is to make sure the two differential signal traces have the same length. I'm using Eagle and it's hard to get them precisely the same length using meander. I can get very close - 0.002% for the transmit pair (37.722068044 mm and 37.722818122 mm) and 0.0004% for the receive pair (15.941376467 mm and 15.941444677 mm). I think receive is ok - I doubt my board vendor has that level of accuracy. But for transmit, I wonder if this is ok? I suspect it's fine but don't want to create a reliability problem.Also, for Kicad users, it is easier/better than Eagle for routing differential pairs like this? I've been telling myself I should switch over but after 20 years, Eagle is pretty ingrained. I've not found anything I can't do with it.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 19, 2020, 06:23:38 am
content: Mind this is PHY side, which is driving a CT winding. The two traces act as stubs against each other, so their lengths should be kept as short as practical, and lengths matched.What level Ethernet? At 100BASE-T, a fewnanosecondsof imbalance would be big deal. That's almost nothing to worry about on a PCB. 1000BASE-T needs to be tighter, but even simply within a few mm is more than good enough!Signal quality really only matters in the extreme, near maximum length, with poorly matched or corroded cables and connectors, poorly made splices, etc. For casual runs say in the 10s of m long, the built in signal quality enhancements of 1000BASE-T more than make up for any of that.Ethernet can literally run on wet string (specifically, brine soaked), albeit at 10BASE-T and only to a fraction of its nominal range. You can't do much wrong to getanyconnection. How good of a connection, and over what distance, is what actually matters.Tim

author: Someone
author_rank: Super Contributor
timestamp: May 19, 2020, 08:52:47 am
content: Fractions of a micron are optical wavelengths. Minimising mismatch in trace length is to keep the differential signals coherent (in phase) at the load. How much energy is there being carried along those traces at those wavelengths?

author: phil from seattle
author_rank: Super Contributor
timestamp: May 19, 2020, 03:50:05 pm
content: Thanks guys, that was my thinking. All the guides just specify exact length and, short of a deep dive, I wasn't sure of the limits of the statement.
Routing gigabit ethernet and TVS's - Page 1
Forum section: electronics / projects

author: Northy
author_rank: Regular Contributor
timestamp: October 13, 2020, 07:36:12 pm
content: Hi all,First time routing gigabit ethernet.I've got to rout the pairs through this TVS:https://www.mouser.co.uk/ProductDetail/Wurth-Elektronik/824001?qs=Wn16VcyqZWpXmk0GJ%252BKnhQ==Has anyone any suggestions on how to do it and keep the pairs impedance matched?Is it just a case of doing it the best you can?I'm really trying to keep all the components on the top side only.Thanks,G

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 14, 2020, 01:14:42 am
content: What impedance tolerance and unpaired length can you tolerate?Tim

author: hoebagg
author_rank: Newbie
timestamp: October 14, 2020, 12:19:06 pm
content: I've only ever had to measure the characteristic impedance of 10g ethernet through harnesses and connectors using a VNA.Characteristic impedance of the ethernet harness was 100 ohms +/- 5 in my case.To minimize losses / reflections you'll want to match the impedance of the cable with the PCB.You'll need to do some math to figure out trace width, pcb material, copper thickness, other layers (assume 4+ layer board?) and match the pcb impedance with the cable... then you can worry about the TVS diodesJ

author: tszaboo
author_rank: Super Contributor
timestamp: October 14, 2020, 12:28:05 pm
content: Quote from: Northy on October 13, 2020, 07:36:12 pmWurth has a lot of information on their website about routing their specific components. For ethernet and USB especially. They also released books about it, called the Triology of Magnetics, one of the books deals with Ethernet, including the magnetics, ESD, Surge protection, POE... And with Wuerth, ask the application engineers, they simply have the best support, even for small customers.

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 14, 2020, 12:43:56 pm
content: Look at how CAT5 or CAT6 is terminated into a wall connector, turns out 1G and below Ethernet is not picky at all.

author: Northy
author_rank: Regular Contributor
timestamp: October 14, 2020, 03:32:31 pm
content: Hi all,The part is:https://www.microchip.com/wwwproducts/en/KSZ9477Nothing at all in the datasheetMicrochip have this app note though:http://ww1.microchip.com/downloads/en/Appnotes/00002054A.pdfIt states:• A single differential pair should be routed as close together as possible. Typically, when beginning the impedancecalculation, the smallest trace space (4 - 5 mils) is selected. The trace width is then adjusted to achieve the necessary impedance.• Differential pairs should be constructed as 100 ohm, controlled impedance pairs.Thanks,G
Routing Under Heat-sinks - Page 1
Forum section: electronics / projects

author: Spark-Doctor
author_rank: Contributor
timestamp: October 27, 2018, 02:57:15 pm
content: Hi AllI am laying out the PCB for a electronic load and have hit a snag. I need to route several large traces under a long heat sink.Is it OK to place the heat sink flat on the board or should i place a few few small stand-offs under the heat sink?I just worry that over time with small amounts of vibration, it will rub through the board coating and the magic smoke will appear.Many thanks in advance

author: Benta
author_rank: Super Contributor
timestamp: October 27, 2018, 03:15:05 pm
content: Yes to standoffs, your concerns are justified. Alternatively, you could place a sheet of silicone rubber (the type used for transistor/heatsink isolation) between PCB and heat sink.The Al-oxide surface on the heat sink is an isolator, but not a reliable one.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 27, 2018, 04:17:34 pm
content: Yeah, that, or some polyimide tape say.You probably can't get a PC-mount heatsink big enough, but spacing it off with washers would be enough already.Tim

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: October 27, 2018, 06:02:20 pm
content: As above, you would never rely on the soldermask for insulation, regardless of voltage or anything else. Standoffs or a sheet of proper insulation. Standoffs might give you a tiny bit of extra cooling because of the gap.

author: coppercone2
author_rank: Super Contributor
timestamp: October 27, 2018, 06:06:17 pm
content: i always meant to simulate what vias do for cooling if under a low heat sink, can they get better convection ging
Roving Networks RN-41 Firmware upgrade. - Page 1
Forum section: electronics / projects

author: liveaxle
author_rank: Newbie
timestamp: March 17, 2015, 08:05:18 pm
content: I'm working on a Bluetooth HID project (a simple PS/2 to BT Keyboard), and I have a couple RN41s with the 4.77 Firmware. My coworker mentioned he may have seen some instructions on how to update the firmware to 6.15 (to support HID mode). Roving Networks official position is that it cannot be done by the user, but I am sure someone has at least tried.I have tried multiple searches in the Eevblog forum and on Google, but I cannot find anything that varies from the official position. Does anyone here have experience with updating the firmware on these? Or have you seen anything with information on it?

author: abyrvalg
author_rank: Frequent Contributor
timestamp: March 17, 2015, 11:10:00 pm
content: Search for "csr bluetooth firmware update"

author: liveaxle
author_rank: Newbie
timestamp: March 18, 2015, 09:12:10 pm
content: Thanks! That is the best lead I have found so far. I think I will be able to suck the firmware out with SPI, but I am still working on a finding something to put the new firmware in. I am hoping to find some sort of fireware update procedure in a Bluecore-4 datasheet, but no luck so far.
Royer oscillator not starting up?  - Page 1
Forum section: electronics / projects

author: Mark
author_rank: Frequent Contributor
timestamp: June 07, 2022, 04:39:40 pm
content: I'm having a problem with the attached Royer circuit, 125VDC input, unregulated 24VAC output.The output then goes to a rectifier and 15V regulator. Normal current draw is 0.06A from 125VDC input.[ Specified attachment is not available ]It seems that when powered up from a slow ramping source there is no problem (e.g. powering up a 125VDC power supply from the mains), but when using a fast ramping source this circuit ocasionally blows the 0.5A fuse (e.g. switching 125VDC to the input).I had a hunch that the oscillator wasn't starting up properly, so I've tested this circuit thousands of times and only once managed to capture this:pink trace shows 125V input,blue trace is the current input,Yellow and green are Q1, Q2 collector voltages.It looks like there is a delay in the oscillation starting, resulting in a current spike, then the oscillation starts but by that time the fuse is on its way out and the fuse blows after 37ms.Would you agree that it looks like the oscillator is not starting immediately and that is causing the higher input current?Has anyone seen this type of problem with Royer oscillators before and how would you suggest I fix the issue?For reference, this is what normally happens, the oscillations start immediately and the input current drops quickly to the 60mA level:

author: mag_therm
author_rank: Frequent Contributor
timestamp: June 07, 2022, 07:51:12 pm
content: Firstly, it is notable that the 2n3439 are able to clear the 0.5 A fuse without one failing.In the old days the circuit sometimes had a starting resistor or RC on one base so that transistor would always start first.Another way is like your circuit, where both are given equal base current via the 39K s and starting relies on slightly different transistor characteristic or core remanence to get one side to dominate in the first pulse.A disadvantage of that is that the remanence of the core may not be consistent every time it is switched off.Looking at the bad trace, it might be showing that there are 3 short pulses with both transistors on together just before the Idc rises.And when the Idc rises, there are 6 long pulses with both transistors out of saturationThat might indicate the the core was initially part saturated and the feedback winding was not giving solid +/- pulses.I think your good trace shows the green transistor conducting first.To help green come on a bit harder, a suggestion would be to change 39K of the yellow channel to say 56 k and "try another 999 "...
RP2040 Inputs (CMOS/TTL/Logic) - Page 1
Forum section: electronics / projects

author: hobbyelectronics
author_rank: Regular Contributor
timestamp: August 26, 2024, 11:01:15 am
content: Hi,This may sound like a silly question , I already have my own answer, but just need to confirm what I think.I need to interface a Broadcom Opto isoloator to the input of a RP2040 MCU.The opto is an ACPL-064-xxx (000, 060 or 560, think its just the reeling / IEC/EN/DIN EN Difference)But some suppliers state the output of the 3 versions differently. Such as CMOS output, Logic gate output etc.I need these to work with the input to a RP2040 MCU. I am sure they all work, but just need to confirm the difference between the 3 versions.Is it only the tape/reeling & IEC/EB/DIN compliance? (Reading page 3 of the Broadcom data sheet)Seems like it is to me, and that the push/pull output on all three version is the same. Just need to be sure, in case I have missed something.Thanks

author: ArdWar
author_rank: Frequent Contributor
timestamp: August 26, 2024, 11:16:31 am
content: Read the datasheet, look at the output voltage level specification, see if it complies with your following device's input voltage level specification.Anyway whether outputs are CMOS/TTL usually doesn't matter that much these days as long as both devices are supplied with the same voltage, data lines aren't excessively loaded and you aren't doing crazy high frequency signaling or something.

author: hobbyelectronics
author_rank: Regular Contributor
timestamp: August 26, 2024, 12:07:22 pm
content: Thanks for your reply.I was trying to confirm if the different versions (000E, 060E, 500E,560E) have any difference in the output. Seems like it mainly is if they are tape/reel or IEC/EN/DIN compliant.Looks like either of the 4 versions will be good. Its only fairly slow monitor of a off board signal anyway.I spent far too much time reading data sheets, and read this one many times over. I have used them for PIC circuits in the past without any issues.I think I was questioning this as various suppliers state the output as either logic state or CMOS for the different -xxx types, but they all seem to have the same push-pull output.Will pick the cheapest I think.Thanks
RP2040 Pico 40pin Package fits ZIF Socket - Page 1
Forum section: electronics / projects

author: WillTurner
author_rank: Regular Contributor
timestamp: July 29, 2023, 02:33:35 am
content: The Raspberry Pi Pico package is very close in dimensions to a vintage 40pin IC, however it is one pin wider. This precludes fitting it into a standard 40 pin IC socket.When I was fishing through my socket collection I found two 40pin ZIF sockets that I bought years ago when I couldn't resist a bargain. They kicked around on the desk for a while, in a jumble of Pico's. Imagine my surprise, when I discovered the Pico H can begently squeezedinto my "standard" ZIF socket.Tinker, and you can get lucky.
RPi Camera in fake camera housing - Page 1
Forum section: electronics / projects

author: davorin
author_rank: Unknown
timestamp: December 24, 2018, 12:37:09 pm
content: EHLO (o;There are many projects around how to use the RPi camera within a fake camera housing....As I just acquired a new 3d printer, namely the Crealtive Ender 3, which is rather cheap, built in better quality and gives nice results, I thought I use it to do the fake camera housing modifications to hold the RPi camera inside...For designing parts like the RPi camera holder I always use OpenSCAD as it gives better control what you are doing...and this is the simple code for the camera holder:Code:$fn = 72;difference() {union() {cylinder(3, 33, 33);cylinder(12, 22, 22);}translate([0, 0, 7]) cylinder(6, 4, 4);translate([0, 0, 9.5]) cube([13, 21, 3], true);translate([0, 0, -1]) cylinder(9.5, 20, 20);rotate(30, 0, 0) translate([30, 0, -1]) cylinder(5, 1.25, 1.25);rotate(150, 0, 0) translate([30, 0, -1]) cylinder(5, 1.25, 1.25);rotate(270, 0, 0) translate([30, 0, -1]) cylinder(5, 1.25, 1.25);rotate(45, 0, 0) translate([33, 0, -1]) cylinder(5, 5, 5);rotate(135, 0, 0) translate([33, 0, -1]) cylinder(5, 5, 5);rotate(225, 0, 0) translate([33, 0, -1]) cylinder(5, 5, 5);rotate(315, 0, 0) translate([33, 0, -1]) cylinder(5, 5, 5);}translate([10.5, 11.75, 5.5]) cylinder(4, 1, 1);translate([-10.5, 11.75, 5.5]) cylinder(4, 1, 1);translate([10.5, -0.75, 5.5]) cylinder(4, 1, 1);translate([-10.5, -0.75, 5.5]) cylinder(4, 1, 1);You can paste it in OpenSCAD, modify and render it, then export as STL file for slicing.And now comes the back part of the housing to hold the power supply connector DC jack.
RPi Compute Module - mechanical support? - Page 1
Forum section: electronics / projects

author: David Chamberlain
author_rank: Frequent Contributor
timestamp: June 10, 2019, 06:14:05 am
content: So I have a Raspberry Pi compute module design. When I did the PCB I put the same 2.3mm holes below where the holes in the CM SODIMM are with the idea of sticking some sort of standoff / spacer in later to provide additional mechanical support in adition to the spring loaded clips of the 200pin DDR2 socket.Well later has come and I just cannot find anything suitable, for the next run I could enlarge the hole in my PCB but was hoping someone might be able to link me a product that works. I would rather not resort to a plastic spacer, washers, nut & bolt combo if I can help it and was hoping for something more elegant.These are good but the recommended drill size is 3mm.https://www.digikey.co.nz/product-detail/en/wurth-electronics-inc/702912000/732-9621-ND/5843781Or these solder metal screw mounts, would also be good but again it's a 3.5mm mount hole, but worst the screw is a M2.5 so larger then the holes in the CM.https://www.digikey.com/product-detail/en/wurth-electronics-inc/9774025151R/732-7078-1-ND/5320683BTW I hate these double ended snap lock ones with a vengeance, please do not recommend them.https://www.digikey.co.nz/product-detail/en/wurth-electronics-inc/709650500/732-10354-ND/6174573Or just tell me I should have put a bigger hole in my PCBThanksDavod
rPi direct to MIPI DSI LCD panel? - Page 1
Forum section: electronics / projects

author: MWP
author_rank: Contributor
timestamp: February 12, 2019, 06:36:46 pm
content: Hi all,I have a project in mind where space is a premium, so im looking to use a rPi compute module, and making my own "motherboard" with a slim LCD panel.I dont have room to deal with HDMI cables / converter boards.So does anyone know of examples of an rPi directly driving a MIPI DSI LCD display panel?I havent found much so far.Thanks in advance!

author: james_s
author_rank: Super Contributor
timestamp: February 12, 2019, 06:49:45 pm
content: I saw a page somewhere about that but now I don't recall where it was. As I recall, the problem is that most modern DSI displays have more lanes than the interface on the RPi provides but I'm pretty sure there was at least one that worked with it.

author: ajb
author_rank: Super Contributor
timestamp: February 12, 2019, 07:50:00 pm
content: Aren't native DSI displays also fairly hard to find in small quantities? Last time I looked that seemed to be the case, lots of Alibaba sellers wanting 1000 piece orders but not much else.

author: SiliconWizard
author_rank: Super Contributor
timestamp: February 12, 2019, 08:24:25 pm
content: You may find some starting pointers here:https://github.com/anholt/linux/wiki/Raspberry-Pi-and-other-MIPI-DSI-display-panels

author: james_s
author_rank: Super Contributor
timestamp: February 12, 2019, 11:31:41 pm
content: There are a lot of small DSI displays available from Chinese sellers, especially OLEDs and replacement smartphone screens. Most of them are newer generations though, the RPi DSI interface is sort of 2010 era smartphone tech.

author: MWP
author_rank: Contributor
timestamp: February 13, 2019, 04:12:47 am
content: Thanks y'all.I have just come across this which looks promising...https://www.thearkadia.com/0 details yet though.

author: tsman
author_rank: Frequent Contributor
timestamp: February 13, 2019, 04:27:53 am
content: Quote from: MWP on February 13, 2019, 04:12:47 amUnlikely it is DSI. This looks to be a parallel interface and will use the DPI peripheral in the Raspberry Pi.

author: technix
author_rank: Super Contributor
timestamp: February 13, 2019, 07:35:52 am
content: If you are using compute module, it might be better for compatibility to run HDMI traces on your board, and use converter IC to get whatever protocol you need.
RPi On/Off Switch - Page 1
Forum section: electronics / projects

author: jwhitmore
author_rank: Regular Contributor
timestamp: January 31, 2016, 06:10:52 pm
content: I found this page out there with a design for an on/off switch for the Raspberry Pi. The circuit is for 5V power supply but I'm going to use it for 12V. I'll have a step down from 12V to the 5V but the 5V in the circuit pictured isn't going to get to an RPi I/O Pin so my using it for 12V should not cause a problem.http://www.raspberry-pi-geek.com/Archive/2013/01/Adding-an-On-Off-switch-to-your-Raspberry-Pi/%28offset%29/2

author: Paul Price
author_rank: Super Contributor
timestamp: January 31, 2016, 06:15:39 pm
content: A much simpler way to completely shut off all power can be accomplished using a simple BJT or P-Chan MOSFET latching circuit, no relays involved.

author: kb0thn
author_rank: Contributor
timestamp: February 02, 2016, 12:49:59 pm
content: We use AP2411S-13. It's a cheap little IC that is a high side switch and over current protection. Works great.

author: jwhitmore
author_rank: Regular Contributor
timestamp: February 02, 2016, 04:20:36 pm
content: Thanks for both of those ideas both of which are much better then a relay. I'll look at both. A single chip high side switch sounds great but I'll have a P channel in my kit bag I can use.
RPi Pico ADC Characterization and Issues - Page 1
Forum section: electronics / projects

author: ferret_guy
author_rank: Newbie
timestamp: March 18, 2021, 04:29:50 am
content: I was disappointed in the details provided for the RP2040 ADC. So I decided to test it myself! I did some testing of a few ADC specs and posted them here:http://pico-adc.markomo.me/The biggest thing is that the ADC has some significant DNL issues. It looks like those were caused by a systematic error in the capacitors for the DAC portion of the SAR ADC.I also discovered the "Low-Noise" mode of the DC-DC converter on the Pico actually has more noise (and the same or worse performance) than the high-efficiency mode.To head off some complaints, I wanted to test the Pico; I was not attempting to measure the RP2040 chip itself, so all the noise, etc... from the Pico is included.Below is a listing of the specs I measured and their results (along with links to the relevant posts)SpecificationTest MethodResult PSMResult PWMPower Supply Noise and SpectrumOscilloscope1.0mV RMS1.3mV RMSInput-Referred NoiseHistogram0.97 LSB RMS1.36 LSB RMSNoise Free ResolutionHistogram9.3 Bits8.8 BitsEffective Resolution(Not ENOB)Histogram12 Bits11.6 BitsEffective Number of Bits (ENOB)Sine Curve Fit8.64 Bits8.48 BitsEffective Number of Bits (ENOB)Coherent Sampling/FFT7.89 Bits7.84 BitsSignal to Noise and Distortion (SINAD)Sine Curve Fit53.77 dB52.82 dBSignal to Noise and Distortion (SINAD)Coherent Sampling/FFT49.27 dB48.96 dBDifferential NonlinearitySine Histogram8.9 LSBsUnchangedIntegral NonlinearitySine Histogram7.85 LSBsUnchanged
RPi PWM GPIO Waveform Stability - Page 1
Forum section: electronics / projects

author: mawyatt
author_rank: Super Contributor
timestamp: December 22, 2021, 05:00:24 pm
content: We have a RPi 400 (and 4) that is used as a controller using Python. GPIO 18 (pin 12) is used as a variable clock source to create a 1Hz to 10KHz programmable clock. Using the standard RPi GPIO PWM method produces a clock that has quite a bit of somewhat random period variations, and doing a search for a more stable output comes up with a hardware PMW mode vs. the standard mode but without details on how to implement in the RPi 4 using Python.Does anyone have a simple RPi 4 with Python solution?Best,

author: thm_w
author_rank: Super Contributor
timestamp: December 22, 2021, 10:59:33 pm
content: https://pypi.org/project/rpi-hardware-pwm/https://forums.raspberrypi.com/viewtopic.php?t=194839https://www.electronicwings.com/raspberry-pi/raspberry-pi-pwm-generation-using-python-and-c

author: mawyatt
author_rank: Super Contributor
timestamp: December 23, 2021, 12:38:29 am
content: Already having trouble with pigpiod but didn't know why, got the error message not recognized by OS. After reviewing raspberrypi forum you pointed out, the thread indicated things changed with the I/O structure in the RPi 4 and the DMA worked differently, thus effecting the pigpio. We updated and upgraded Raspbien OS, then the OS would recognize sudo pigpiod and now we can use the pi.hardware_PWM() command.So it seems this issue has been corrected with the RPi 4 in the latest OS upgrade/update.Thanks for the help, much appreciatedBest,
RPi solar-weather-station - Page 1
Forum section: electronics / projects

author: cloidnerux
author_rank: Contributor
timestamp: November 02, 2013, 01:48:25 am
content: Hello folks,I came here, to present my "little" weekend-project, occupying some of my following weekends.It is a solar-powerd weather station with wifi, based upon a RPi model A and some sensors.Pictures of the hardware so far are on my flickr:http://www.flickr.com/photos/97274236@N02/sets/72157637208072896/As you may see, it is some kind of hackadelic construction with meters of enamelled wire and some SMD parts where neededThat's all for now.Greetings

author: Harvs
author_rank: Super Contributor
timestamp: November 02, 2013, 02:36:38 am
content: That wiring certainly doesn't look like the easy way of doing it!If you are doing a lot of that sort of point to point wiring, have a look for some Kynar Wrapping Wire, it's a heck of a lot easier to work with (same sort of diameter, but just strip it and it's pre-tinned.)

author: cloidnerux
author_rank: Contributor
timestamp: February 09, 2014, 02:07:07 pm
content: It took a little bit more than a few weekends, but after a little bit of adding details it seems to work for now.Pictures can be seen in the linked flickr album.It currently can mesure temeprature, pressure, humidity, rain and wind direction, wind speed gets added later.QuoteIt is easier than many other ways and it mostly reduces mistakes as its mostly point to point wiring, but for more than prototypes it is not suited.
RT809H Universal Device Programmer – List of Supported Devices? - Page 1
Forum section: electronics / projects

author: Chris56000
author_rank: Frequent Contributor
timestamp: December 16, 2017, 05:36:51 am
content: Hi!Can anyone tell me if the RT809H universal programmer supports all the eproms, EEPROMs, flash, MCU, gal/pal and offer the basic TTL/CMOS tests of some of the slightly cheaper devices?The descriptions of all those I've seen on fleabay are somewhat "Chinglish" nonsense and there doesn't appear to be a definitive list – the TL866 and it's slightly more expensive variants claim approx,. 14000 devices usable!Can anyone clarify?Chris Williams

author: eevblogger88
author_rank: Contributor
timestamp: May 18, 2022, 10:39:07 pm
content: The RT809H seems to support approx. 40.000 devices. While the T56 does only support approx. 30.000.Here you have the list:https://www.hklrf.com/24download/img/RT809H-List.txt
RS-232 board for GPS modules (Trimble Resolution-T, Adafruit, CN06, etc) - Page 1
Forum section: electronics / projects

author: texaspyro
author_rank: Super Contributor
timestamp: December 20, 2017, 02:16:33 am
content: A few years ago I did a board for adding an RS-232 interface to the Trimble Resolution-T timing receiver. It also has connectors and mounting holes for the Adafruit Ultimate GPS and CN06 receivers and can be used with any GPS module with logic level serial ports. It also works with Nick Sayer's Venus Skytraq timing receiver that is pinout compatible with the Adafruit.I've also found the board to be handy as a general purpose RS-232 interface. There is a small proto area and a footprint for a DIP-8 package processor.I've received a few inquiries about the board. The layout (Eagle .brd file) is available as a shared project on OSHPARK.COM. You can order it from OSHPARK or download the .brd file and submit it to dirtypcbs, etc.https://oshpark.com/shared_projects/YPvKgMYaA voltage regulator / RS232 breakout board. Has mounting holes for the Adafruit Ultimate GPS, CN06 (Ublox Neo 6M) and Trimble Resolution-T receivers. Others receivers can be easily wired to the board.Silkscreen says CP3232 RS-232 converter chip. These can be picky about their caps. Use a MAX232A with all 0.47 uF caps (MAX232A’s seem to work just fine on 3.3V... beware of fakes on Ebay. I've also used plain MAX232's with 0.47 uF caps without any problems). The bypass caps marked 0.1uF can also be 0.47uF.Regulator is any AMS1117 compatible fixed regulator. You can use 3V or 5V regulators depending upon what your receiver wants.The PWR RAW/REG jumper selects whether the GPS receiver/MAX232A power comes from the regulator or the input jack.The RS232 PWR jumper connects pin 9 of the RS232 connector to the DC input jack. Or can be wired over to the regulator output.The PPS polarity jumper selects polarity of the PPS pulse to the pin 1 of the RS232 connector.There is an 8-pin DIP pattern for an ATTINY85, etc processor and a small prototype area.Resolution-T antenna power is wired to Vcc, but there is a place to cut the etch marked on the board along with a hole for providing an alternate source of antenna power.
RS-232 / I2C Chip - Page 1
Forum section: electronics / projects

author: docmur
author_rank: Regular Contributor
timestamp: September 23, 2013, 02:45:16 pm
content: Is there an RS232 chips like the Max232 that outputs over I2C?

author: deephaven
author_rank: Frequent Contributor
timestamp: September 23, 2013, 02:54:14 pm
content: The MAX232 and similar are just RS232 interface level translators. You need 2 chips to do what you want, the MAX232 plus something like a MAX3107 which is an I2C UART.
RS-422 switch L2 - Page 1
Forum section: electronics / projects

author: S. Petrukhin
author_rank: Super Contributor
timestamp: December 15, 2020, 10:53:58 am
content: Friends, hi!What do you think, is it really possible on one chip STM32, for example, to make a UART receiver/transmitter on 16 or 24 ports?It is clear that there is no such number of hardware UARTs, but how will UART sowtware emulators feel in such a number?Or should I only rely on the FPGA?There is an idea to make a switch similar to Ethernet for connecting a star over the RS-422 line for transmitting packets.Ethernet is not suitable because it has a short distance limit.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: December 15, 2020, 11:46:52 am
content: At what baudrate?And how many channels will be active at the same time?I think some of the STM32 chips go up to 8 hardware UART's, and some of the other peripherals may be used to assist software decoding.If you want all 24 ports Full Duplex @ 10MBps, then an FPGA is definitely the way to go.On the other hand,experimenting with some software UART's is a good project for intermediates which already got some uC experience. A UART is a pretty simple device on itself, and easy to emulate in software. When you start using a multitude of them and have them ISR controlled you get pretty complex interactions and it can be a good learning experience to get to understand how hardware and software interacts.You will also NEED a Logic Analyser for this, to measure things like jitter and other timing issues due to software latencies.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: December 15, 2020, 12:23:07 pm
content: Quote from: Doctorandus_P on December 15, 2020, 11:46:52 am10 mbit per 1-2km will not flyWe are talking about the standard 9600 or a step or two higher.All ports can work simultaneously and exchange arbitrarily with each other.Yes, the serial port is very simple, I can easily, for example, on a timer interrupt, receive streams from 32 pins and simultaneously transfer other streams to other 32 pins. But this only works if there is a synchronous transmission, when all the threads start at the same time. A small accumulating phase shift and I can not process incoming streams on one clock signal from one timer. It is necessary to perform phase adjustment on the starting bit, and this is a significant acceleration of the timer, so that you do not go beyond the error limit by the end of the word.
Rs 485 Transmitter Design Using  Only NPN Transistor - Page 1
Forum section: electronics / projects

author: haydar40
author_rank: Newbie
timestamp: June 16, 2025, 05:18:33 pm
content: Hello ,in this project,I wanted to design a circut that acts as a transmitter betwen the Mcu and the RF line,like the Max485 intagrated circut.The difference from Max485 is that it will only act as a sender.I was able to disagn such a circut with only NPN transistors and communicate with the PLC via Profibus.I designed the circut taking into account Profibus requirements.I did not communicate with my circut for a long time.Sometimes there were conneciton errors in Profibus.I experinced this situation in a few attempts.I want advice fromyou to improve my circut.What i did wrong and what ı should add to make it work more stable.Thanks you.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: June 16, 2025, 10:26:35 pm
content: Quote from: haydar40 on June 16, 2025, 05:18:33 pmYou can improve your circuit by replacing the whole shebang with an RS485 driver.

author: Benta
author_rank: Super Contributor
timestamp: June 17, 2025, 12:01:18 am
content: Quote from: Doctorandus_P on June 16, 2025, 10:26:35 pmActually, that would be an RS-422 driver. Plenty on the market.

author: haydar40
author_rank: Newbie
timestamp: June 17, 2025, 05:06:39 am
content: Thank you for your answer. Since my main goal in this project is to design an rs485 transmitter, it is illogical to use the already existing ones at this stage.

author: gerbay
author_rank: Regular Contributor
timestamp: June 17, 2025, 05:38:09 am
content: differantial driver:differantial receiver:

author: gerbay
author_rank: Regular Contributor
timestamp: June 17, 2025, 05:59:54 am
content: ds9638 equivalent circuit:

author: tooki
author_rank: Super Contributor
timestamp: June 17, 2025, 07:22:50 am
content: Quote from: Benta on June 17, 2025, 12:01:18 amHow do you figure?Electrically speaking, an RS-485 driver or receiver is fully compatible with RS-422, but not the other way around.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: June 17, 2025, 01:07:09 pm
content: Quote from: Benta on June 17, 2025, 12:01:18 amOp mentioned the Profibus compatibility goal, which uses EIA-485 (RS-485) according to Wikipedia:https://en.wikipedia.org/wiki/Profibus.For the rest, nothing wrong with experimenting a bit with discrete transistors. One of the most important properties of the drivers is symmetry between the two channels. Any asymmetry increases EMI, even if the shift is far to small to cause data error concerns.