hybridfree/eevblog-posts huggingface dataset:
USB powered dummy load: M102v5 - Page 1
Forum section: electronics / projects

author: technix
author_rank: Super Contributor
timestamp: September 19, 2015, 04:48:25 pm
content: This is a microcontroller-controlled dummy load with USB connectivity.I have actually rolled PCB for M102v3 and v4 but none of them worked! Dammit... If anyone want it I can sell you one unpopulated PCB for two US dollars each. You can saw the digital section off and use the high current section for your own project. Also the v3 PCB contains a working SDB628 boost circuit and v4 PCB contains a working MC34063 boost circuit and you can saw that section off for your own purpose too.M102v5 fixed bugs caught in M102v4 and added one important feature: analog (aka no microcontroller intervention required) thermal shutdown.Features:* Two current ratings: 5A version with 1 ohm sense resistor and maximum current of about 4.5 amperes, 10A version with 0.47 ohm sense resistor and maximum current of about 9.6 amperes.* Three DAC resolution: 8, 10 or 12 bits.* Automatic analog thermal shutdown with adjustable shutdown temperature.* Fully digitally controlled with USB connectivity.* USB bus powered.* Isolated communication and power, maximum isolation voltage 1kV.* Reduced human interface of one 16x2 LCD screen and four buttons, advanced features requires computer software to use.* Optional built-in real time clock with replaceable backup battery.* Optional datalogging with timestamps, capacity from 512 points to 8k points.* Power MOSFET options: IRF540 or IRFP250 (both available for both current ratings.)To build a M102v5 model number:Series and Version: M102v5DAC resolution: -8, -10 or -12Maximum current: F5 or F10Power transistor: /540 or /P250For example: M102v5-10F5/540 - M102v5 with 10-bit DAC, 5A maximum current and IRF540 as the power component.Also don't bug me with "star grounding" thing - I used one single continuous ground plane.
USB powered solder smoke fan build - Page 1
Forum section: electronics / projects

author: Teljemo
author_rank: Contributor
timestamp: November 23, 2014, 08:02:09 pm
content: Made a small fan that blows away the smoke when soldering...made it out of a video card cooling fan..here is the clip on my site:http://www.workshopprojects.net/usb-powered-solder-smoke-fan/direct link to my youtube channel:https://www.youtube.com/channel/UC3gzJ5q340VA1yf9Icxp4EA
USB problems -a clarification - Page 1
Forum section: electronics / projects

author: IconicPCB
author_rank: Super Contributor
timestamp: December 07, 2019, 03:34:51 am
content: I have a problem with an industrial USB2.0 camera.The camera works on an older Lenovo i5 gen4 PC.It refuses to operate correctly on a newer Gigabyte AMD Ryzen5 motherboard.An identical camera on a shorter USB 2 cable operates correctly.The camera which is misbehaving is tethered on a home made cable about 4.5 meter long. As indicated camera and cable ok on Lenovo PC , NOT OK on Gigabyte X470 Ryzen5 PC.Please make the curtain before my eyes drop away let the vistas open.

author: wraper
author_rank: Unknown
timestamp: December 07, 2019, 04:01:08 am
content: Maximum length limit for Hi speed USB is 5 meters. You are going near to max spec. Probably you made DIY out of spec crap cable and particular implementation of USB is less robust against it. Try different ports, some may have separate USB chip, not coming straight from chipset.

author: wraper
author_rank: Unknown
timestamp: December 07, 2019, 04:08:06 am
content: Also note that even if such motherboard have USB 2.0 ports, they are basically crippled USB 3.0. That's why simply installing Windows 7 on such hardware will result in all USB ports being non functional. While in older hardware with mix of USB 3.0 and true USB 2.0, slower ports would still work outright.

author: IconicPCB
author_rank: Super Contributor
timestamp: December 08, 2019, 04:59:52 am
content: Wrapper,Thank You for the sensible commentary.I need to further test these ideas to confirm the root of the problem. I hope to be able to find a USB2 PCIe card and tryit out instead of the motherboard based USB2.0 offerings. Incidentaly the ryzen board is runing win10 1908 .Device manager identifies NO usb 2.0 resources .despite the fact that the motherboard exposes four 2.0 ports.

author: wraper
author_rank: Unknown
timestamp: December 08, 2019, 05:17:26 am
content: What is that home made cable? Is it a proper cable with twisted pair and decent shielding?

author: IconicPCB
author_rank: Super Contributor
timestamp: December 08, 2019, 11:19:48 pm
content: The imprint on the cable isSuntone 22AWGX2P AWM20276 105C 300VVW-1 CE ROHS 10078Construction consists of two twisted pairs wrapped in aluminium (?) foil shield and a decent coverage of wire braid ( in a criss cross pattern).In addition there are four or five fibre threads interspersed within the bundle.At first look a reasonable selection but without data sheet hard to determine just how good it is.Being at the limits of line length ... problems.
USB Protected Switch Multiple Manufacturer - Page 1
Forum section: electronics / projects

author: Infrared_Fred
author_rank: Regular Contributor
timestamp: January 25, 2021, 08:43:18 pm
content: Hello!I am looking for a high side 5V switch with either an adjustable current limit or one preset for somewhere between 400-600mA(one with a preset anywhere in that range is OK). Since it will be for a hopefully published/open source type project, I am trying to use parts that are common and thus (usually) made by several manufacturers (ex. LM358, 555 timer, 2N3904/6, etc) so that they are easy to obtain and not likely to go obsolete. Additionally, it would need to be aviable in a easy to solder package like a DIP, SOIC, or SOT. In the project, it will be switching power from a USB port so that basically USB power is connected if only USB is available then the swtich is on, but if extrenal power (through a 7805 5V regulator on board) is connected then the switch is off.Thank you for the help!

author: thm_w
author_rank: Super Contributor
timestamp: January 25, 2021, 11:07:03 pm
content: You can search here:https://www.digikey.ca/en/products/filter/pmic-power-distribution-switches-load-drivers/726Choose appropriate output currents that are acceptable, they have many in the 500mA range, SOIC8 and SOT-23. See if there is anything that looks good and report back. Commonly used for 5V USB power.
USB Reclocker with a USB3503 - Page 1
Forum section: electronics / projects

author: asder
author_rank: Newbie
timestamp: December 23, 2020, 02:53:17 pm
content: Hello, I want (/try) to make a usb "reclocker" with a microchip USB3503 (https://www.microchip.com/wwwproducts/en/USB3503).I tried to copy their reference design a bit. I have some questions.1. If the design seems fine ?2. I suppose there won't be a serious ground loop if I use a floating power supply for powering the hub& usb device ?3. The chip specifies multiple selectable frequencies for the clock, would be there an optimal one or the jitter will be approx. the same ?I uploaded schematic and pcb on gdrive (https://drive.google.com/drive/folders/1QB0DL1XM0Zy-uJKBMOA2jOVjXIITp05o?usp=sharing)[ Specified attachment is not available ]
USB reset occurs-to Cypress CX3 - Page 1
Forum section: electronics / projects

author: Vcky_electro
author_rank: Contributor
timestamp: March 10, 2020, 06:10:15 am
content: Hi ,Cypress CX3 chip is getting reset when powered from Win10 PC USB 3.0 port, when It consumes 570mA.But when i using powered hub for the device it is not reset. I have also probed the waveforms there is no dip in the voltage.Can anyone share any idea how to debug further ??Thanks..Vicky
USB RTLSDR, Need 3.3 and 1.2 power rails. Best option for low noise/ripple 1.2v - Page 1
Forum section: electronics / projects

author: rwgast_lowlevellogicdesin
author_rank: Frequent Contributor
timestamp: August 06, 2015, 06:43:51 pm
content: So im just constructing some mods for an RTL-SDR dead bug style on copper clad, I intend to actually encase it all in copper clad seems like and easy way to turn you ground plane into a shield!Anyways im tying to get everything off the PCB that's not needed and replace the power rails. Im using a sheilded USB cable with a ton of feright's either slipped on or wrapped as chokes. This then runs in to an LM2937 LDO to create the 3.3v rail. Ive tested it out it seems to have about 700uV ripple under 500mA load.So I need to figure out a way to do the 1.2v rail, to replace the switching supply on board. Im trying to just use things I have around. And the three options Ive come up with are as follows....LM317 droping out from 5v USBLT3080 dropping from 3.3v regulatorA few diodes dropping down from 3.3 regulator.I have never used diodes to drop off voltage for a rail, the 1.2v supply takes about 200mA of current. I know I can source the appropriate diodes for this. My question is which one of these options will give me the cleanest power out? Im not sure if diodes emmit any noise kind of like resistor johnson noise issues....So what do you guys reccomend.

author: tszaboo
author_rank: Super Contributor
timestamp: August 07, 2015, 11:33:16 am
content: None of the above. The 317 is usually too noisy for it, and goes down to 1.25, some might do 1.2The diodes give you and unregulated voltage, and this is not the 70s anymore where ICs are expensive.The LM3080 is just Linear Technology's joke that they can sell stuff doing the job of a half dollar IC for 4 dollars (Look Ma, only one ressitor!)Use something like the TPS796. That has RF in it's name, should eb good for RF, right?

author: rwgast_lowlevellogicdesin
author_rank: Frequent Contributor
timestamp: August 07, 2015, 06:47:26 pm
content: Well thanks for the tip, im looking at the TI part right now.... Its not money that was my concern its more of waiting around for the LDO to come.I dont own a very good scope its only a 25mega sample pc scope from parallax, but im seeing very little ripple on my LM2937, do you consider these good low noise LDOs? And is the 3080 pretty noisey, obviously you dont like it but i have a few on hand never used them.... just would like to know why its not a great part, other than the problems dave had with it trying to do something out of spec.
USB SDIO 2.0 Bridge - Page 1
Forum section: electronics / projects

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: July 14, 2017, 05:07:32 pm
content: Hi,Am trying to test a Bluetooth/Wifi module with SDIO interface, and i had no luck with both laptop i have with built-in SD card reader (based on realtek RTS5129 chip) cause apparently while it can read SD cards, it's not fully SDIO 2.0 compatible so it can't run anything else with this interface. (stupid Dell)So am trying to find an USB reader that can be compatible with that, must reader i found use express port instead of USB.5$ Chinese reader are obviously not what am looking for (not that i didn't try) they use mass storage usb class.Anyone can recommend a USB SDIO interface available on ebuy or amazon ?lot of thanksHamdi

author: daveshah
author_rank: Unknown
timestamp: July 14, 2017, 06:33:53 pm
content: I think this is going to be tricky to find. I believe most USB SD card readers convert from USB mass storage to SD so wouldn't support SDIO. At a quick Google there are some chips that support SDIO over USB but I'm not actually sure what USB protocol they use.

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: July 15, 2017, 04:58:27 pm
content: Quote from: daveshah on July 14, 2017, 06:33:53 pmYap tricky to find. Didn't do much search this day so still looking.i found a motherboard of an old laptop (HP) i use to have an SD controller AU6433 appear to be SDIO compatible and using USB interface, if i have any luck i may be able to power up this part of the board ... seems like a huge waste of time.
USB Shield Grounding - Page 1
Forum section: electronics / projects

author: Pack34
author_rank: Frequent Contributor
timestamp: March 03, 2017, 05:32:19 am
content: This is in reference to this thread:https://www.eevblog.com/forum/projects/usb-shield-ground-connection/msg726591/To be clear, the rule of thumb is:Keep the ground plane solid and connected to the shield for best emissions. However, in some conditions isolation is needed and the shield needs to be connected to the ground plane through a high value resistor and a low value cap.Is there a detriment to splitting the grounds but connecting them with a 0-ohm resistor as standard? Emissions are great, design works fine, but a specific customer is having an earth ground loop problem. To keep a single design I could populate the high-R and low-C for the small volume customer and 0-R for everything else.

author: amitchell
author_rank: Regular Contributor
timestamp: March 03, 2017, 05:40:16 am
content: Quote from: Pack34 on March 03, 2017, 05:32:19 amI went through this same USB ground crap recently and that is exactly what I did. Both sides of the connector populated with R and C and if I need too I will just populate with 0R. At least it covers your butt for both situations. I really got tired of flipping back and forth, and everybody has a different opinion on it...

author: Pack34
author_rank: Frequent Contributor
timestamp: March 03, 2017, 07:38:21 pm
content: Quote from: amitchell on March 03, 2017, 05:40:16 amDid this hurt emissions at all? It's my main point of concern.

author: amitchell
author_rank: Regular Contributor
timestamp: March 03, 2017, 08:56:17 pm
content: Quote from: Pack34 on March 03, 2017, 07:38:21 pmI am not that far enough along in the project to test that, I was just leaving my options open.
USB Shield in a DC circuit for GoPro - where to connect? - Page 1
Forum section: electronics / projects

author: ooftech
author_rank: Newbie
timestamp: February 14, 2017, 07:46:16 am
content: Hello,I have been looking online but cannot find a definite answer for this. I am using a DC-DC converter to step 12v down to 5v to power a few GoPros. The mini usb end of the cable plugs into the gopros and the other end gets cut and wired to the DC-DC converter. I understand the USB cable red wire goes to (+) and black wire goes to (-) on the converter, but what to do with the shield? I have heard some people say leave it unconnected, some say connect to system ground, but can't find a solid answer. Should I connect it to the DC (-) on the 5V side of the converter? The cables I am using have the shield connected between the two end connectors casings, so when I cut the cable, one end is not connected to anything anymore. I am not using any of the data wires, just power.The complete power flow goes from a two prong 12V AC/DC adapte to the DC/DC converter, then to the gopros. I realize I could just use 5V power supplies but I have other devices in my setup that need 12V and want to use one power supply.I am using this converter:https://www.amazon.com/gp/product/B01MAWMW0W/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1ANY help is greatly appreciated!

author: ooftech
author_rank: Newbie
timestamp: February 19, 2017, 07:23:44 am
content: Bump. Can anyone advise?

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 19, 2017, 07:30:18 am
content: Just connect it to the same ground as the 5V side.

author: ooftech
author_rank: Newbie
timestamp: March 01, 2017, 12:03:59 pm
content: Direct connection or do I need a resistor in between? This will sometimes be powered off of batteries, so there is no real "ground". If I connect the shield to the negative will there be any potential for the current to flow the wrong way up the shield and harm the cameras? Does EMI really only matter for the data wire and not for the power wires?Thanks!

author: DBecker
author_rank: Frequent Contributor
timestamp: March 01, 2017, 05:54:48 pm
content: You aren't transmitting data, so leave the ground disconnected.USB cables are shielded, and the shield continues to the connector shell, to prevent interference. Leaving the shield disconnected risks coupling additional noise to and from the data pair. Connecting it runs a (small) risk of ground current and ground loops.In this case the shield might end up transmitting the switching power supply transients, while providing no noise margin benefit.

author: ooftech
author_rank: Newbie
timestamp: March 01, 2017, 07:06:23 pm
content: Gotcha, so I'll leave the shield disconnected at one end and just connect the USB (+) and (-) power wires. The shield will still be connected to the connector shell at the gopro mini usb end of the cable, but not at the 5v converter end.See, two different people, two different answers on what to do with the shield.Thanks!
Usb signal decoder from CSV - Page 1
Forum section: electronics / projects

author: krzycho1024
author_rank: Newbie
timestamp: September 07, 2016, 12:18:42 am
content: It's my first post. Hello EEVblogI have Rigol 1054Z which unfortunately can't decode USB signals, but it can save captured data into CSV.So I made small tool that can decode USB 1.1 signal wire.Sources, example files and usage on GitHub:https://github.com/krzycho1024/pyCsvToUsb
usb signal to sinewave - Page 1
Forum section: electronics / projects

author: Alexandros81
author_rank: Regular Contributor
timestamp: November 06, 2013, 04:34:35 pm
content: Hi I want to manipulate the usb voltage levels via a program written in ? language so to produce a sine wave with 5-15kHz frequency. How can it be done? I have no clue.I would like to have a window on my laptop that manipulates the frequency and the voltage level of the sine wave.

author: dannyf
author_rank: Super Contributor
timestamp: November 06, 2013, 04:52:43 pm
content: QuoteI would start right there.

author: Balaur
author_rank: Unknown
timestamp: November 06, 2013, 05:02:52 pm
content: Use the existing soundcard or any cheap USB one + any software that allows you to produce sounds (Audacity, SoundArb, ...)

author: casinada
author_rank: Frequent Contributor
timestamp: November 06, 2013, 05:06:38 pm
content: Please set your profile to show your country. Also post your age and what do you want to accomplish.Use any sound producing program and use the audio outputa simple search found :http://www.nch.com.au/tonegen/orhttp://www.electronics-lab.com/downloads/pc/005/

author: Jon86
author_rank: Frequent Contributor
timestamp: November 06, 2013, 05:34:43 pm
content: It'll be difficult to filter out a squarewave to a sine wave over difference frequencies, easy at one but not so easy over a range. As suggested, use a USB sound card or just the speaker output.

author: FrankBuss
author_rank: Unknown
timestamp: November 06, 2013, 05:48:46 pm
content: Obviously Alexandros81 has no idea how USB works and that the outputs are digital, only, but nevertheless could be interesting to abuse an USB host controller to create a high frequency PWM signal, which then could be filtered to create a sine wave in the required range
USB stick with USB A, USB-C and lightning - Page 1
Forum section: electronics / projects

author: mrburnzie
author_rank: Regular Contributor
timestamp: March 02, 2023, 03:06:38 pm
content: I would like to build (not buy) my own usb stick that has an USB-A, USB-C and lightning jack.The USB is easy, but the lightning is not. How and where do I find a apples lightning jack?

author: tooki
author_rank: Super Contributor
timestamp: March 02, 2023, 04:12:12 pm
content: You don’t. To get them, you have to register as an Mfi (Made for iPhone) program as a hardware developer, which individuals cannot apply to. Lightning connectors — real ones, at least — are strictly controlled and not available on the open market.And I wouldn’t trust a third party one since the authentication chips might not be reliable.
USB to Battery Switching Circuit - Page 1
Forum section: electronics / projects

author: Twistx77
author_rank: Regular Contributor
timestamp: May 20, 2014, 11:29:21 am
content: Hi,I'm working in a project where I need to have two souces of power being one of them two AA batteries and the other a USB cable.I wan't to be able to use the batteries and when a USB is connected automatically cut off the drain of the AA batteries and use the USB instead to power my device.I know I could use a simple diode to do the trick since the USB voltage will be higher than my two double AAs but for me having that diode means wasting precious energy (about 40mW for a 0.2V schottky diode).So I designed a simple circuit that might be a solution.I would like to know what you guys think and if you know a better solution for this.Also, I would like to know if someone knows a pmos better suited for this application.Attached are the the images of the circuit and the simulation results ( Output voltage and Batteries current)

author: Sam__
author_rank: Regular Contributor
timestamp: May 20, 2014, 11:44:00 am
content: Might be worth having a 10k (or higher if power consumption is your worry) pulling the vUSB input to the comparator down when the input is floating.

author: Twistx77
author_rank: Regular Contributor
timestamp: May 20, 2014, 11:51:40 am
content: Good idea, thanks.

author: ludzinc
author_rank: Unknown
timestamp: May 20, 2014, 12:09:35 pm
content: The comparator doesn't work when VUSB isn't present.So why not just tie VUSB direct to the 'FET?

author: Sam__
author_rank: Regular Contributor
timestamp: May 20, 2014, 12:12:31 pm
content: Looks like a good choice of mosfet, very low RDSon.

author: Twistx77
author_rank: Regular Contributor
timestamp: May 20, 2014, 12:39:46 pm
content: Quote from: ludzinc on May 20, 2014, 12:09:35 pmI can't do that, if I connect it directly then the gate and the 3V battery will be shorted when the USB is not connected, so the mosfet will be working like a resistor. I could use a diode in the 5V rail to avoid that problem but that would mean that if I use an external USB battery pack I will be wasting power in the diode.
USB to Ethernet Extender CH317 Info - Page 1
Forum section: electronics / projects

author: OneGeekGuy
author_rank: Regular Contributor
timestamp: January 28, 2025, 07:28:22 am
content: Hi everyone!,I am working in a project in which I would need to extend an USB2.0 communication for around 5-10m. After taking a look, I found some options from TI (Redrivers) which allows you to extend the USB between 5-10m it depends if you use 1 or two devices, one on each end. But after looking at the forum, I also saw the device CH317, which basically create a transparent link between the USB TARGET and the HOST using Ethernet, which I tend to like more since probably is going to be more reliable.I wanted to ask, if someone has experience with this chip CH317, I was looking into WCH website and the information/datasheet is really limited, I contacted them but due to the Chinese new year I will need to wait, considering that they might not even answer.I was looking for a possible alternative to this chip, but I was not able to find anything similar from another brands which would not require a big SW/FW implementation.Any information will be welcome! Thanks and regards.

author: voltsandjolts
author_rank: Unknown
timestamp: January 28, 2025, 09:23:07 am
content: There's a myriad of options for extending usb that are available off the shelf. Are you sure you want to design your own usb extender?

author: OneGeekGuy
author_rank: Regular Contributor
timestamp: January 28, 2025, 12:27:21 pm
content: Thanks @voltsandjolts , off the shelf solution might be an option for sure, just for the sake of integration I am evaluating all the possibilities.

author: spostma
author_rank: Regular Contributor
timestamp: February 02, 2025, 07:36:10 pm
content: instead of using the CH317, I would suggest to use the newer CH318 chip:https://www.wch-ic.com/downloads/CH318DS1_PDF.htmlI have used it with a 10G ethernet transformer,and it gives you twoisolatedUSB2 ports over a single pair of a 20m CAT7 cable.Instead of 10G ethernet transformers, capacitors may used for shorter distances.Besides, it also has a multi-transaction hub that speeds up low speed traffic sharing on an USB2 bus.Wonderful chip, simple, low cost, works flawlessly!

author: OneGeekGuy
author_rank: Regular Contributor
timestamp: February 03, 2025, 10:21:28 am
content: Thanks @Spostma!At least there is more information for this device which helpsI will take a look, also good to know that you already used it.Would be good if these guys from WDH improve a bit their documentation.Regards!
USB to SATA Bridges? Parts availability? - Page 1
Forum section: electronics / projects

author: Zeigren
author_rank: Newbie
timestamp: December 01, 2017, 04:10:41 pm
content: I've been looking around for a USB to SATA bridge and the only ones I can get in small quantities from the likes of Digikey or Mouser are TI's TUSB9261 or TUSB9260.Which is fine, but they're both slightly overkill for my application so I'm trying to find a cheaper option.Both of them support USB 3.0, but I only need USB 2.0 support.Everything else I've been able to find I either need to order 1000+ of or I can only find it in small quantities on Aliexpress. I would much rather buy something from a reputable source.Thanks!

author: flyingfishfinger
author_rank: Contributor
timestamp: December 01, 2017, 06:10:54 pm
content: What abouthttp://www.genesyslogic.com/en/product_view.php?show=1? You can probably call them for small quantities of samples. For that matter, you can probably also sample the ones you mentioned for "cheap" or free...R

author: Zeigren
author_rank: Newbie
timestamp: December 06, 2017, 06:10:11 pm
content: It never hurts to ask right?I might end up selling this later, so I'll have to see what their minimum order quantity would be then.Oh their website is down right now, I'll have to check it out later then.

author: IanB
author_rank: Super Contributor
timestamp: December 06, 2017, 06:15:29 pm
content: There seem to be many retail solutions for this as a complete assembly with connectors and cables. For example Fry's usually has a variety in stock.If I understand correctly you are just looking for just the chip?

author: Zeigren
author_rank: Newbie
timestamp: December 06, 2017, 06:42:39 pm
content: Yep just looking for the chip.You would think with how prevalent external hard drives are that these ICs would be easier to find.

author: IanB
author_rank: Super Contributor
timestamp: December 06, 2017, 07:14:29 pm
content: I suspect they are all manufactured and marketed in China...

author: PA0PBZ
author_rank: Super Contributor
timestamp: December 06, 2017, 07:32:34 pm
content: Quote from: Zeigren on December 06, 2017, 06:42:39 pmI more and more see drives with USB on board. Bought a few to use the drives as SATA drives but yeah...

author: Swake
author_rank: Frequent Contributor
timestamp: December 10, 2017, 05:44:44 pm
content: Search for usb 2.0 to sata adapters on your preffered Chinesium supplier, they go for 2€ including shipping. Salvage the parts and connectors, or do as I did and use them as is on the raspi for a small NAS
USB to serial converter termination - Page 1
Forum section: electronics / projects

author: drummerdimitri
author_rank: Frequent Contributor
timestamp: June 15, 2020, 03:11:24 pm
content: I just received this USB to Serial converter cable:https://www.aliexpress.com/item/4000570382636.html?spm=a2g0s.12269583.0.0.390f2b8bk7eW2bwhich is plug and play sowindows automatically downloads the driver for it but when I try to plug it into my Meanwell TN-1500 inverter via a RJ11 connection and make sure the hardware and software are using the same COM port and BAUD rate, I get a "Inverter not found" error message.I cut the end off the cable thinking the original cables pin configuration may be wrong for my inverter and there are three conductors inside (black white and green) but since I don't have the pin-out, I cannot follow the manual (see attached manual, page 3) to crimp a new RJ11 connector with the correct wire arrangement.Does anyone have a clue what conductors correspond to the correct pins from 1-6 on an RJ11?

author: MarkF
author_rank: Super Contributor
timestamp: June 15, 2020, 04:07:29 pm
content: Paragraph #2 in your linked document gives you the pinout.You may need to swap TXD and RXD?With a meter you can find what color is ground and guess at the other two colors.

author: Ian.M
author_rank: Super Contributor
timestamp: June 15, 2020, 04:20:46 pm
content: Diagram A in the manual you attached shows the relationship between the RJ11 pinout and the standard DE-9 PC COM port pinout.To identify the wires:The ground wire should have continuity back to ground on the USB connector, and if you plug the cable into a PC and open the port in a terminal program, with no data being sent, one of the remaining wires will be a floating input (RxD) which will measure close to 0V and the other (TxD) will output a voltage: +5v or +3.3V if its a logic level (aka: 'TTL') USB serial adapter, and negative -5V to -25V (but unlikely to be more than -9V) for a true RS-232 levels USB serial adapter. Seehttp://tldp.org/HOWTO/Serial-HOWTO-19.htmlThe two types of adapter aren't compatible, your inverter expects true RS-232 levels and, as its only got three wires, almost certainly doesn't provide USB Vbus so you cant use a MAX3232 serial level converter chip, so if you measure a positive voltage with the port open, you'll need to get a different adapter (preferably one with a DE-9 plug as they almost invariably use RS-232 levels).
USB to UART Design (earth referenced) - Page 1
Forum section: electronics / projects

author: advark
author_rank: Contributor
timestamp: July 17, 2022, 09:19:43 pm
content: Hello Everyone,I'm currently working on a DC Load project. I designed it so it can be autonomous (i.e. logging to its internal memory) but it can also be hooked to a PC for continuously logging data onto a HDD. The MCU is a PIC24HJ128GP510A. My goal is to also the USB ground, which is earth referenced when hooked to a PC. My idea is to use a USB isolator (ADuM3160) and then feed a CY7C64225 to convert the signal to UART. The unit is power by an 18VDC wallpack adapter, so there is no earth reference coming from the unit PSU.My concern is when the unit is used when not connected to a PC. Then the "earth" ground is now floating since there is no connection between the USB earth and the PSU common (GND). This also means the chassis is no longer "grounded" to earth. Connecting earth to DGND and/or AGND would solve the issue in this case but it will also means the whole device will now be earth referenced when hooked to a PC, which I would like to avoid. Could this be an issue with the DC wallpack: connecting earth to the common wire?If instead I build an internal PSU (transformer, diode bridge, etc), I could use the unit's power cord ground wire to connect to the chassis and problem solved. But wouldn't that create some kind of ground loop if the unit and the PC are connected to different wall sockets?Thanks for any insights.A confused hobbyist

author: Ian.M
author_rank: Super Contributor
timestamp: July 17, 2022, 10:20:02 pm
content: It would make more sense to opto-isolate the serial signals between the USB UART chip and the PIC24. The USB chip would then be bus powered by the PC host, and would be floating when USB isn't connected. You may want a 1Meg resistor between USB 0V and PSU common to discharge any static before it can build up enough to cause an ESD event.Whether or not you then need to ground the case and PSU common depends on the needs of your application. Mains powered equipment can be designed not to need a ground, but Y-capacitor leakage current from switched mode PSUs can be a significant issue. However if it can function with USB disconnected, you should NOT rely on the USB shield for ground and should *NEVER* rely on it for a safety ground.

author: advark
author_rank: Contributor
timestamp: July 17, 2022, 11:39:25 pm
content: QuoteOMG! I was so minded of isolating the USB jack that I never thought isolating the USB chip! ESD buildup had never came to mind, though. Thanks for the hint.Ian, you're my new best friend

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 18, 2022, 12:22:11 am
content: Metal enclosure? If the load must be isolated, then isolate it from the chassis, and hard ground the chassis. Fuse the input (both sides) to protect against internal faults to GND.When I made mine,I put the control circuit referenced to load negative, and isolated the interface (just serial) and used a small supply inside for isolated DC. An IEC C13 receptacle provides power and ground, highly overkill but handy enough.Tim
USB-TTL Converter (CI-V) - Page 1
Forum section: electronics / projects

author: wyphy
author_rank: Contributor
timestamp: December 29, 2014, 05:30:28 am
content: Working up a USB to serial TTL converter project for control of a device, an Icom CI-V converter to be exact.I'm getting an Icom IC-7000 in a week or so and want to be able to computer control the functions.Couple of reference pages :http://ok1zia.nagano.cz/wiki/CI-V_interfacehttp://www.plicht.de/ekki/civ/civ-sch2.htmlWorking off the reference pages, I came up with a circuit based on the FTDI FT232R chip in the attached photo.The only real difference from the first reference is the TXD and RXD lines connected directly together at the chip side rather than isolated, as in with the MAX232 design in the second reference.Question is, will this cause an issue for the FT232?The MAX232 seems to not have a issue there, but different chip, different source signals (USB vs. RS232).Thanks much for your opinions and suggestions.Background on CI-V, if you're interested :http://www.plicht.de/ekki/civ/civ-p1.html--Edit--I realised after posting that I'd left out the filtering coil and cap for the output.It's late and I've since corrected it.

author: kingofkya
author_rank: Regular Contributor
timestamp: December 29, 2014, 06:40:38 am
content: Should be fine that how you generally test the chip, using it as a loop back device anyways.
USB type B socket, centre colour - Page 1
Forum section: electronics / projects

author: fcb
author_rank: Super Contributor
timestamp: February 03, 2014, 12:25:45 pm
content: Anybody know if their is a difference between USB type B sockets with a white(cream) insert and a black insert? Does the colour signify anything?http://uk.farnell.com/lumberg/2411-02/usb-type-b-receptacle-panel/dp/1177885http://uk.farnell.com/lumberg/2411-03/usb-type-b-receptacle/dp/1308876Data sheet for above:http://www.farnell.com/datasheets/1698414.pdf

author: Fabiusp98
author_rank: Contributor
timestamp: February 03, 2014, 12:40:43 pm
content: Nothing, the usb standard doesn't mention that and a different color plastic doesn't make any difference.

author: codeboy2k
author_rank: Super Contributor
timestamp: February 03, 2014, 12:44:57 pm
content: as Fabiusp98 said, there is no difference physically. However, note that in the two you linked to, the black ones have gold plated contacts and the white/cream ones have tin plated contacts. Not only that, the gold plated ones cost less...However... the datasheet doesn't say that, so it may be a mistake on the Farnell page, and they are both tin plated

author: Monkeh
author_rank: Super Contributor
timestamp: February 03, 2014, 01:42:25 pm
content: Pretty sure they're both gold plated.These certainly are, though:http://uk.farnell.com/te-connectivity-amp/292304-1/usb-type-b-tht-connector-4p/dp/1076665

author: fcb
author_rank: Super Contributor
timestamp: February 03, 2014, 02:15:31 pm
content: Fabiusp98: I thought it might be so - it seemed quicker to post here than read the standard (I did read it once, many moons ago).codeboy2k: yeah, I noticed that to, perhaps it's just a supply/demand thing.Monkeh: Actually that's the part in my inventory!

author: Monkeh
author_rank: Super Contributor
timestamp: February 03, 2014, 02:28:47 pm
content: Quote from: fcb on February 03, 2014, 02:15:31 pmStick with it!
Upgrading to USB Type C (USB2.0) DRP (Dual Role Port) - Page 1
Forum section: electronics / projects

author: suku
author_rank: Contributor
timestamp: July 16, 2018, 11:43:11 am
content: In the USB micro B receptacle we had an ID pin that was used the notify the microcontroller that an On-The-Go adapter/device is connected, the controller could then reconfigure its USB peripheral to fulfill USB-Host duties.I'm upgrading a design to uses the type C receptacle, where instead of the ID pin we have CC1 and CC2 logic. What I'm looking for is an interface chip (like the TUSB320LA) with the following requirements:1. It negotiates the usb host/device roles (DRP)2. It outputs the ID logic3. It receives the maximum allowed current @5V4. It has built-in ESD protection for D+/D- lines5. It preferably doesn't need I2C for configuration4 & 5 is what makes me unhappy about TUSB320LADoes anyone have hands on experience with upgrading designs? Please share the knowledge!Thanks!

author: krho
author_rank: Regular Contributor
timestamp: July 17, 2018, 03:22:16 pm
content: Look at what on-semi has to offer e.g FUSB303. I know that they do have the complete port controllers where you can do the whole power delivery and custom peripheral support.I've looked at the ton of those controllers and what I remember is that almost all of them have I2C as a requirement.

author: towlerg
author_rank: Contributor
timestamp: July 18, 2018, 01:20:05 pm
content: Perhaps programme a Microchip Pic with OTG?Microchip make a large range of USB hubs and interfaces.

author: krho
author_rank: Regular Contributor
timestamp: July 19, 2018, 04:03:59 am
content: Quote from: towlerg on July 18, 2018, 01:20:05 pmThis is bad advice.. some lines in USB-C can go up to 20V.. so you need the protection. Most of the USB-C compatible CC/VUBS etc.. drivers can go up to 28V on those lines
USB type C alternate mode (DP) to iPad3 display. - Page 1
Forum section: electronics / projects

author: zavdimka
author_rank: Newbie
timestamp: April 01, 2025, 01:56:32 am
content: I'm working on an adapter to connect an iPad3 display directly to USB-C. The iPad3 display uses DisplayPort, which seems straightforward, but I'm having trouble with the USB-C Power Delivery (PD) part.Here’s what I’ve done so far:Using an STM32G0B1C to handle PD negotiation (switching to Alt Mode).Developed in STM32CubeIDE with the built-in PD library.Used STM32CubeMonitor-UCPD for logging—logs show all steps passing, and the lines should be multiplexed to my laptop’s GPU.The Problem:After receiving DISPLAY CONFIGURE REQ, I set: DP_HPD = 0, SBU_EN = 1But when I plug it in… nothing happens—Windows doesn’t detect the display. 😕What I’ve Tried:Flipping the USB-C connector orientation.Removing the MUX (D1) and connecting wires directly.Playing with pull-up/down resistors.Still no luck. Am I missing something obvious? Any suggestions would be greatly appreciated!
USB type c connector pin shorting - Page 1
Forum section: electronics / projects

author: pree
author_rank: Contributor
timestamp: March 03, 2025, 09:29:31 am
content: Hi I am using a IPX8 USB type c connector and the application is where the unit should be usable when in water. But the water in the USB connector cause short circuit between the UART bus and the GND.How can I fix it? any suggestion.Due to this the TX pin of the UART cause the MCU into test mode and the unit does not turn ON.

author: fchk
author_rank: Frequent Contributor
timestamp: March 03, 2025, 09:38:33 am
content: Use a different connector.Many connectors require a cover when not mated.

author: pree
author_rank: Contributor
timestamp: March 03, 2025, 11:57:42 am
content: Do you have some part number to suggest?

author: fchk
author_rank: Frequent Contributor
timestamp: March 03, 2025, 07:11:07 pm
content: https://www.amphenol-socapex.com/de/sites/default/files/media/document/2023-07/USB3CF%20TV_datasheet.pdfThe receptacles are IP68 rated even in unmated state, but then water will get into contact with the socket.You should use the offered protective cap in order to prevent this. They offer them for a reason.Warning. This is MIL-style stuff and quite expensive.Do you need seawater resistance? Ask them beforehand. Seawater is quite corrosive.Do you need pressure tightness for deep sea underwater operation?->https://www.glenair.com/underwater-and-subsea-connectors/index.htm(validated up to 7000m water depth)->https://www.te.com/en/products/brands/seacon.html?tab=pgp-story

author: ajb
author_rank: Super Contributor
timestamp: March 03, 2025, 07:51:18 pm
content: Quote from: fchk on March 03, 2025, 07:11:07 pmSeawater is certainly worse, but even pure water will result in serious corrosion if there is any voltage present on the connector while it's wet. Even if it starts out perfectly pure, water will easily pick up enough chemical impurities from the environment/surfaces to begin conducting, and it will rapidly pick up more once corrosion starts. Even a weak pullup resistor on one of the signal lines might be enough to cause corrosion problems.Quote from: pree on March 03, 2025, 09:29:31 amYou would have to either not allow water to get into the USB port in the first place, as others have noted, or somehow detect that the port has been contaminated and disable the problematic functions. A lot of phones do the later, disabling the port to prevent damage and notifying the user. I'm not sure how they implement the detection, presumably looking for unusual impedances/voltage levels on various pins. Maybe that's a feature built into a USB C front-end ASIC? In the case of a UART, the pin being shorted to ground continuously should cause a framing error -- detecting that, or some other invalid message and disabling the test mode might work, depending on the specifics of the application and how the UART is used.
USB TYPE C Connector without PD controller and MUX controll - Page 1
Forum section: electronics / projects

author: electronx
author_rank: Regular Contributor
timestamp: February 08, 2025, 04:21:16 pm
content: I want to use a usb type c connector without a usb pd ic, I will trick the USBC1_CC1_DUT and USBC1_CC2_DUT pins with resistors to be dfp, there is no problem here but they felt the need to mux the lanes in the design.In this case, what should I do here? How do I choose which lane to use for data transfer? Would it be a good choice if I left the mux selection with the pull up or pull down resistor in hardware and decided which lane to choose?A USB keyboard and mouse will be connected via this port

author: gabiz_ro
author_rank: Regular Contributor
timestamp: February 08, 2025, 05:11:08 pm
content: I don't think you can use both, mouse and keyboard, in the same port and same time.Each one per port.Since mouse and keyboard most likely will be USB2.0 (1.1 or 2.0 Full speed) :5K1 from CC1 to GND, 5K1 from CC2 to GND resistors and D- to pins A7and B7, D+ to A6 and B6 GND to GND and VBUS to VBUs

author: ejeffrey
author_rank: Super Contributor
timestamp: February 08, 2025, 05:53:40 pm
content: For USB 2.0 you don't use the high speed lines that need multiplexing. The connector will have two copies of D+/D-. Only one of them will be connected to the wires on the cable depending on orientation. You simply connect them together on the PCB and then to your host controller. No MUXing is needed or useful.

author: moffy
author_rank: Super Contributor
timestamp: February 08, 2025, 09:44:07 pm
content: Just for reference, the select pin of the mux can be driven by a comparator that detects whether CC1 or CC2 has a voltage present.
USB Type-C Passthrough - Page 1
Forum section: electronics / projects

author: MobileWill
author_rank: Regular Contributor
timestamp: March 25, 2016, 04:49:05 am
content: Is anyone familiar with working and routing type-c? I am working on a pass through breakout and I am not sure about matching the pins. Can TX1 and TX2 be tied together for less pins to route? Or just route them all TX1 to RX1 and so forth. I found out while working with USB3 that TX/RX is swapped in the actual cable so since I am passing through and using two cables I have to swap TX/RX on the PCB I assume this would be the same for Type-C or does the DFP Mux take care of that.Another thing that is bothering me is how can USB3 be rated for so much current with such small pads/pins? Same really goes for USB2. For multi-amp traces you need some wide traces but its always larger than the pads/pins.Thanks for the help.

author: Jeroen3
author_rank: Super Contributor
timestamp: March 25, 2016, 06:33:09 am
content: I think you can make a straight pass trough.There are 4 pairs of power pins. That is 700mA per pair.http://pinoutsguide.com/Slots/usb-type-c_pinout.shtml

author: Psi
author_rank: Super Contributor
timestamp: March 25, 2016, 07:13:37 am
content: 700mA?USB3 power spec allows for 20V @ 5A over usb cables.

author: Jeroen3
author_rank: Super Contributor
timestamp: March 25, 2016, 11:24:52 am
content: 5A? I was not aware. I understand your concern.

author: Dago
author_rank: Frequent Contributor
timestamp: March 25, 2016, 12:16:21 pm
content: Quote from: Psi on March 25, 2016, 07:13:37 amHowever USB type-C ports are not required to support USB power delivery 2 (which contains those additional higher voltage/power profiles), it is optional.

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: March 25, 2016, 12:18:00 pm
content: Not all cables will be rated for 12/20v, and most connections won't offer more than the allowed 7-900mA.But if you take a look at the MacBook 2015 C connector, it looks like they will distribute the power over multiple pins to the motherboard:https://d3nevzfk7ii3be.cloudfront.net/igi/eGKXdIClPNJXel1Z.hugeGuess more reading is available to read athttp://semiaccurate.com/2012/07/23/100w-over-usb-is-here-with-the-new-power-delivery-spec/

author: MobileWill
author_rank: Regular Contributor
timestamp: March 25, 2016, 02:30:20 pm
content: So it sounds like I shouldn't tie VCC pins together like in attached picture.I am trying to stick with 2 layers but it will be tough with so many traces and being differential pairs.That is way I was trying to see if I can tie some of them together but then I guess that would cause branching on the signal traces. Actually since one set if a pad and the other through-hole that would also be a stub unless I use a via but not much room plus still be branched.Hmm, this is leaning toward 4 layers more and more.
USB Type-C PD controller & USB UART bridge - Page 1
Forum section: electronics / projects

author: galvanix
author_rank: Contributor
timestamp: October 24, 2022, 07:11:32 pm
content: I'm looking for an IC that offers a USB to UART bridge together with a USB Type-C PD controller. The only chip I've come across so far is the FTDI DT232HPQ, but the datasheet is honestly not that great. From what I can gather an external EEPROM is required for operation in anything but the standard USB PD mode 5V/3A. I'd assume that EEPROM needs to be programmed somehow as well so I'd still need a specialized programmer.Are there any other chips that offer USB Type-C PD support and a USB to UART bridge? This is for an ESP32 project which would really benefit from a combination of the two. Given how convenient of a solution this is I'd imagine there would be more than one suitable chip on the market.Do you know of any crowd favorites for this kind of solution?

author: jbb
author_rank: Super Contributor
timestamp: October 24, 2022, 07:59:42 pm
content: On the FTDI part: it might be that FTDI offers some PC (Windows/Linux/Mac) software which can program the EEPROM via USB for you. (For the FT230 lineup there’s FT_Prog, which works well enough.)
USB Type C - VBus voltage? - Page 1
Forum section: electronics / projects

author: Northy
author_rank: Regular Contributor
timestamp: December 06, 2020, 10:03:59 am
content: Hi,Sorry, another USB Type C question.Who (UFP or DFP) is responsible for requesting what voltage VBus can be? It must be the UFP, but would it be the CC controller that signalled to the DFP that it could cope with a higher voltage? Or the USB Sink?Does anyone know of any laptops or mobile devices that can output more that 5V on VBus, or is that really for "chargers" connected to laptops etc. Would a Laptop ever supply a higher VBus to a plugged in mobile device to charge it?Thanks,G