USB to serial converter for Windows 11 - Page 1
Forum section: electronics / general

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 25, 2025, 09:54:35 am
content: I have a couple of USB to serial converter I got from Startech and they are based on the Prolific PL2303TA. Windows 11 said it's not supported. Changed the driver and it worked a bit then doesn't work again later. I would like recommendation for new ones that are better than these that I have.

author: darkspr1te
author_rank: Frequent Contributor
timestamp: May 25, 2025, 10:03:08 am
content: I try and go for original FTDI based for RS232 and TTL level serial.other models to try are WinChipHead or wch based serial converters.darkspr1te

author: tooki
author_rank: Super Contributor
timestamp: May 25, 2025, 10:12:48 am
content: FTDI-based ones seem to cause the absolute least issues across platforms. But I’ve also had no trouble with the CP2102N (used on most ESP32 boards), on both Windows 10 and 11, and on Mac.Some manufacturers, like Tripp Lite (now Eaton) are really good about noting which of their adapters use FTDI.What I would probably say to avoid is the ones from Moxa: they use a TI chipset that nobody uses. Admittedly we’ve had no trouble with them on Win 10 after installing drivers, but we could not get them to work on Linux at all. FTDI was no trouble.

author: Psi
author_rank: Super Contributor
timestamp: May 25, 2025, 10:12:58 am
content: If you have to install an older diver version to get it to work be prepared for a battle with windows constantly trying to update back to the latest diver and having to roll it back yourself every time it does. Windows will always try to "fix" older driver version with newer ones

author: Psi
author_rank: Super Contributor
timestamp: May 25, 2025, 10:17:40 am
content: Quote from: tooki on May 25, 2025, 10:12:48 amI can second this, I have CP2102 on an active product with no issues.

author: tooki
author_rank: Super Contributor
timestamp: May 25, 2025, 10:25:25 am
content: Quote from: Psi on May 25, 2025, 10:17:40 amJust out of curiosity, do you use the CP2102, or the newer CP2102N?

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 25, 2025, 10:40:35 am
content: I am thinking of getting the StarTech ICUSB2321F which is based on the FTDI chip. Now I wonder if it would work with Windows XP as I still use XP.

author: jpanhalt
author_rank: Super Contributor
timestamp: May 25, 2025, 11:05:14 am
content: I have used both the CP2102 (not N version) and FTDI 232 (3v3) on a Windows 11 laptop. I use the same FTDI in a Windows 7 desktop. I suspect it will work on XP, but haven't tried it. I have not tried the CP2102 on my Win 7.

author: themadhippy
author_rank: Super Contributor
timestamp: May 25, 2025, 11:37:18 am
content: if yer looking for these to use on a desktop pc you might wanna check your motherboard manual as a lot of boards still have headers for the ole serial port ,you just need a suitable back plate.

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 25, 2025, 01:34:39 pm
content: Quote from: themadhippy on May 25, 2025, 11:37:18 amMy desktop does have both PCI and PCI-e slots avaialble but first I prefer the port in the front because it's difficult to get to the back of the computer where it is now. Also I do use laptops and do need the RS-232 ports for them too. My older desktop which I still used have 2 serial ports on the motherboard.

author: DavidAlfa
author_rank: Super Contributor
timestamp: May 25, 2025, 01:43:06 pm
content: Likely they're counterfeit chips, that's why.Install old driver again, don't change the usb port or you'll have to reinstall the driver again, as Windows will install the updated driver by default.

author: ataradov
author_rank: Super Contributor
timestamp: May 25, 2025, 03:15:55 pm
content: CP2102 has one huge advantage over FTDI - it is a standard USB CDC ACM device, which means drivers are supplied by the OS vendor as part of the USB stack. You don't need any proprietary vendor drivers, which can brick your devices.

author: voltsandjolts
author_rank: Unknown
timestamp: May 25, 2025, 04:05:59 pm
content: Can you program custom vendor strings into the CP2102, and still keep the plug-n-play CDC, driverless feature?No inf file required?

author: voltsandjolts
author_rank: Unknown
timestamp: May 25, 2025, 04:20:07 pm
content: Quote from: ataradov on May 25, 2025, 03:15:55 pmYes, that can happen if you are using counterfeit devices of various manufacturers, not just ftdi.If you're unsure if you have genuine devices, then you have a supply chain problem. Don't use AliX and eBay!

author: ataradov
author_rank: Super Contributor
timestamp: May 25, 2025, 04:27:03 pm
content: Quote from: voltsandjolts on May 25, 2025, 04:05:59 pmI don't know how custom string programming works in CP2102, but they are 100% not necessary for the driver identification. It happens purely based on the configuration descriptor. If it says that device is CDC ACM, Windows will install the driver.

author: coromonadalix
author_rank: Super Contributor
timestamp: May 25, 2025, 05:00:11 pm
content: for specific vendor ids or else i only know ftdi chips can be reprogrammed with ftprog, even the non genuinesas for the drivers, block windows from updating any drivers, and put back the old ftdi before the ftdi gate, it will not mess the genuines and non genuinesCh340 based interfaces = no problems with them tooProlific so so, older chipsets dont work well even if you play with some drivers, you have to be sure you have the latests ones and compatibles chipsets ...for ftdi you have some with a buffer ic between the ftdi and the rs232 port, blue colored, never failyeah thoses darn TI interfaces chips, i had some weird ones and lots of compatibility problems, just an pc in english was crashing a driver version, and in french it was an older one ... for me it's avoid at all costshad design changes because of thatin the end it's a matter of finding a good one and keep it, or buy many of the same modelsme it's genuine ftdi, or CH340 i do have duinos with fakes ftdi, still working ... ive kept ftprog just in case

author: tooki
author_rank: Super Contributor
timestamp: May 25, 2025, 07:09:01 pm
content: Quote from: ataradov on May 25, 2025, 03:15:55 pmYou sure about that?!? Silabs itself says theirs arenotCDC ACM devices: “we have dedicated device drivers for our CP210x on mac and linux, and so these devices aren't actually CDC ACM class devices.”(https://community.silabs.com/s/question/0D51M00007xeTjASAU/options-for-usb-serial-device-on-efm32gg11-cdc-acm-and-others?language=en_US)“CP2102N is not a CDC class device. it uses a custom VCP driver written and maintained by Silabs, and not the CDC driver in Windows. Silabs provide the VCP for windows, linux and OSX.”(https://community.silabs.com/s/question/0D51M00007xeKvBSAU/cp2102-cdc-communications-device-class?language=en_USand expand the top answer)The Prolific PL2503 is advertised as being one:https://prolificusa.com/product/pl2503-usb-cdc-acm-serial-uart-bridge-controller/Some say the MCP2221 is, and I think but am not sure if the datasheet actually fully confirms this or not:https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/20005292C.pdf

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 25, 2025, 09:07:15 pm
content: Quote from: DavidAlfa on May 25, 2025, 01:43:06 pmNot countefeit as first I bought all these units directly from StarTech. Second StarTech tech support said that Windows 11 doesn't support that model. Third the newest driver for the 2303 does say that it doesn't support the PL2303TA version for Windows 11.

author: ataradov
author_rank: Super Contributor
timestamp: May 25, 2025, 10:03:52 pm
content: Quote from: tooki on May 25, 2025, 07:09:01 pmI'm probably confusing them with Prolific then. I remember some of the big vendors used CDC ACM.The overall idea here is the same - only use device that advertise CDC ACM to get the best out of the box experience on al OSes existing and new.

author: oPossum
author_rank: Super Contributor
timestamp: May 25, 2025, 10:37:11 pm
content: Prolific was (still is ?) an extended CDC ACM protocol. CDC ACM doesn't support all the handshake lines, so Prolific used a few undefined bits to add support for them. I don't think they identified as class compliant in the USB descriptor, so Windows needed a specific driver.

author: wraper
author_rank: Unknown
timestamp: May 25, 2025, 11:36:06 pm
content: I would not touch Prolific chips with a 10-foot pole. Their chips were constantly cloned and they did not think anything better to fight that than releasing updated chips with a different suffix and quickly dropping driver support for prior ones. FTDI had a fuck-up when they bricked counterfeit chips with their driver and some driver version incorrectly recognized some batch of genuine chips as fake (without bricking them) but they never pulled something so stupid as intentionally fucking with users of their genuine chips.

author: jpanhalt
author_rank: Super Contributor
timestamp: May 26, 2025, 05:54:36 am
content: With regard to my prior comment (post #8), the reason I did not try the CP2102 on my Windows 7 machine is the current "universal" driver from Silicon Labs is presumably not compatible. I could not find legacy drivers on its site. Is there a trusted site for them?

author: Psi
author_rank: Super Contributor
timestamp: May 26, 2025, 06:34:21 am
content: Quote from: tooki on May 25, 2025, 10:25:25 amCP2102N i can't recall exactly when we switched.

author: voltsandjolts
author_rank: Unknown
timestamp: May 26, 2025, 06:52:38 am
content: WCH seems to have CDC (no driver required) and VCP (driver needed, extra features/speed?)https://www.wch-ic.com/products/categories/46.html?pid=1#datae.g. CH343 datasheet says "Support free installation OS which built-in CDC driver or multifunctional high-speed VCP vendor driver."I've never tried them though.

author: thm_w
author_rank: Super Contributor
timestamp: May 26, 2025, 10:36:22 pm
content: Quote from: wraper on May 25, 2025, 11:36:06 pmYeah looks like these a-holes are auto-installing a driver that says "not win 11 compatible" even though it works fine:https://embetronicx.com/uncategorized/fixed-prolific-pl2303ta-usb-to-serial-and-windows-11/Maybe there is some way to use zadig or similar program to permanently change the driver type, not sure..

author: SiliconWizard
author_rank: Super Contributor
timestamp: May 26, 2025, 11:46:34 pm
content: I know that many people still remember the FTDI bricking fake chips situation, but keep in mind they have learned their lesson and never did it again - so you won't have any chance of getting into this situation unless you use a now very old driver, so that's not going to happen on Windows 11 - and that it only ever affected the FT232R, which still exists but is itself a pretty old chip by today's standards. If you buy anything FT230X-based, which I recommend, there is absolutely zero chance of any counterfeits (that I know of). FTDI drivers are rock solid on Windows, so if on Windows, I definitely recommend the FT230X. The chip is only a couple bucks, so cost is definitely not an issue.

author: tooki
author_rank: Super Contributor
timestamp: May 27, 2025, 06:56:46 am
content: As an aside, this entire discussion just makes clear why an updated, more capable generic driver class is needed. :/

author: sleemanj
author_rank: Super Contributor
timestamp: May 27, 2025, 09:14:49 am
content: WCH CH9102 is pin compatible with the CP2102, and is a USB CDC device.Just take note of decoupling, in my experience the CH9102 wants 100nF decoupling cap right on the V3 pin, the CP2102 is more tolerant (chinese designed CP2102 module with a cap miles away on the board didn't work well with CH9102 dropped in, put cap close, problem solved).

author: Psi
author_rank: Super Contributor
timestamp: May 27, 2025, 09:34:03 am
content: Are any of the STM32 built in USB VCP implementations true USB CDC ?

author: ataradov
author_rank: Super Contributor
timestamp: May 27, 2025, 02:03:33 pm
content: All embedded USB stacks implement standard CDC ACM as far as I know. They don't need the extensions vendors usually need and MCU vendors don't want to mess with custom drivers.