Which USB<>Serial chips have direct support in Windows OS? - Page 1
Forum section: electronics / beginners

author: LinuxHata
author_rank: Frequent Contributor
timestamp: October 31, 2022, 04:37:33 am
content: Hello.I'm building a small educational device for a school, where kids will connect it to their laptops via USB. I'm using serial port connection, so some kind of IC should be used. There are many of them - CH340, PL2303, HX1203 and so on. Since I never used any of them, I'm curious, which one from them is directly supported by windows? (32 and 64 bit), so kids won't need to install drivers separately?

author: Andreas
author_rank: Super Contributor
timestamp: October 31, 2022, 05:00:57 am
content: Hello,on WIN10 I had to install the ch340 manually.FT232RL installed automatically.with best regardsAndreas

author: ataradov
author_rank: Super Contributor
timestamp: October 31, 2022, 05:06:12 am
content: FT232RL installs automatically because vendor drivers are included with the OS (hence the bricking after OS update).None of the devices mentioned in the OP will work without drivers. What are you looking for is CDC ACM support. This is pretty rare in standard ICs.PL2503 is explicitly advertised as one, but it seems to be an overkill for this. And I'm not even sure it is available.

author: magic
author_rank: Super Contributor
timestamp: October 31, 2022, 07:02:48 am
content: I don't think any Prolific ICs at all are available anywhere in small quantitiesThis includes PL2303. There is a lot of fakes on AliBay, though. Beware that many of them are compatible with PL2303HXA and Prolific removed support for that chip from their Windos drivers to disable the fakes. Better fakes are compatible with PL2303HXD/TA/SA - hell knows how long these will be supportedI wouldn't recommend Prolific, either fake or genuine, for something that has to keep working on Windos in the long run.A CDC ACM version should technically be free from this problem, but I suppose they still could do something about it if they wanted to.Genuine FT232 from a reliable source doesn't look too bad in comparison. Dunno about OSX, but it's plug and play on Windos, Linux and even most BSDs, I think.

author: SmallCog
author_rank: Frequent Contributor
timestamp: October 31, 2022, 10:17:14 am
content: My workplace has incredibly strict IT policies. New software and drivers have to be threat assessed before they’re permitted for installationI use these and the RS485 version without any drivers being required on our heavily restricted work computershttps://ftdichip.com/products/usb-rs232-we-1800-bt_0-0/Having LED’s in the plug end makes fault finding easy too, not flashing your on the wrong port, only flashing one colour check your settings etcNot cheap, but just works

author: coromonadalix
author_rank: Super Contributor
timestamp: October 31, 2022, 11:46:33 am
content: Even if you have strict policies, normally you have to make them inspected before any use is made ... and you install them afterwardsI worked in a military facility ...FTDI, Prolific, CH340, Cypress ... needs driver installation at one time, normally Windows should be blocked to download any drivers automatically ... per policyAsk your technical service to install them IE: use one brand / one model or serial cable onlyNot sure for other ic's who do usb to serial interfacing

author: HwAoRrDk
author_rank: Super Contributor
timestamp: October 31, 2022, 02:10:11 pm
content: Holtek HT42B534-2claims to support CDC.(Notenotthe HT42B534-1, that is the older model.)I've used the older model and they work quite well. The VID/PID and description strings can be customised if so desired. Although I've read that they are a bit flaky at very high baud rates (e.g. 1Mbps+), but perhaps that's something they fixed in the new model (claims up to 3Mbps).Edit:I mis-remembered, the HT42B534-1 was also a CDC device. Kind of irrelevant anyway, considering it is now EOL.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: October 31, 2022, 06:59:19 pm
content: This chip works well and is easy to use:https://www.digikey.com/en/products/detail/silicon-labs/CP2102N-A02-GQFN24R/9863479

author: ataradov
author_rank: Super Contributor
timestamp: October 31, 2022, 07:05:12 pm
content: They all work. CP2102 still needs vendor drivers.

author: voltsandjolts
author_rank: Unknown
timestamp: October 31, 2022, 08:28:18 pm
content: You could use a cheap USB MCU with some firmware for CDC or a WinUSB plug-n-play USB device (so kids don't have to find the right COM port).On this educational board maybe the MCU would be useful for other tasks too.If you are unsure about firmware, I'm sure the forum can help with that

author: LinuxHata
author_rank: Frequent Contributor
timestamp: October 31, 2022, 08:31:27 pm
content: Well, I can source directly from China, so in that area I have no issues.Regarding the speeds, my device will operate at 9600bps, so speed is also no issue at all.Holtek chips seem to be the interesting choice, ordered couple of them, let's see.Regarding the USB MCU, I have done some HID devices, like volume control keypads, with PIC18F series chips. But in this case, all I need is the simple serial connection. The "core" of device runs on PIC16F628A, so there's really no point for going into "high end" hardware.Regarding the port choice, they will be using laptops, and I haven't seen a laptop with serial port for a while....

author: PureBasic
author_rank: Newbie
timestamp: January 16, 2024, 10:53:07 am
content: Hey LinuxHata,I'm designing a board right now and have spotted the Holtek USB-UART chips also. Did you ever got them working? Just to check if they are a pain to use with windows/linux/macos.Cheers

author: radiolistener
author_rank: Super Contributor
timestamp: January 17, 2024, 02:37:13 am
content: they all needs driver install. If you're looking on aliexpress, I suggest CH340, they works good enough.Note that FT converters from China often are fake and there are a lot of issues with it, because genuine driver has protection which can wipe out chip eeprom on fake chips at random time so it stops to work.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: January 17, 2024, 02:47:14 am
content: Quote from: ataradov on October 31, 2022, 07:05:12 pmDon't particularly remember being prompted to install drivers.

author: ataradov
author_rank: Super Contributor
timestamp: January 17, 2024, 03:11:41 am
content: Quote from: JustMeHere on January 17, 2024, 02:47:14 amThat's because Windows packages a lot of standard drivers. This is how FTDI managed to brick all those devices.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 17, 2024, 03:14:25 am
content: some prolific are not good for recent os like win10 or 11the easiest are the FTDI ones, and yes in some drivers updates they where automatically installedch340 need driversunless you have some cdc or hid devices, lots of usb to serial ic's need driversand while you ask this, are your pc or lappy managed, meaning you can not install yourself the needed drivers ?@ataradov dont bring back the FTDI gate here

author: alligatorblues
author_rank: Regular Contributor
timestamp: January 17, 2024, 09:30:48 pm
content: Quote from: LinuxHata on October 31, 2022, 04:37:33 amFTDI chips are pretty standard. They work on everything I've tried. But USB is 2 comm and 2 power. Whereas serial is 8 comm and ground. So, you want to make sure the cchip you use passes the pins you need on the serial side.

author: LinuxHata
author_rank: Frequent Contributor
timestamp: January 26, 2024, 04:43:39 am
content: I'm using holtek chips. They come with software to change device name, so now when you plug your device into computer, the name you defined will be shown, instead of generic usb to serial bridge.

author: Careless
author_rank: Newbie
timestamp: September 10, 2024, 08:05:50 pm
content: Quote from: LinuxHata on January 26, 2024, 04:43:39 amHi LinuxHata,Can you provide more information on which USB controller you went with and what software you are referring to?I can't seem to narrow it down on the holtek website. I would like the same capability to rename the item when plugged in for easier ID.Thank you.

author: Andy Chee
author_rank: Super Contributor
timestamp: September 10, 2024, 08:26:41 pm
content: I use CP2102 which also allows device renaming (allowing multiple CP2102 connected to the same computer).The Windows CP2102 software is somewhat annoying, but the renaming process is much easier using Linux.https://blog.manzelseet.com/fixing-cp2102-with-custom-vidpid.html

author: Nominal Animal
author_rank: Super Contributor
timestamp: September 10, 2024, 10:45:18 pm
content: Why don't you use a microcontroller with a native USB interface in the first place? USB CDC endpoints aren't difficult to implement.(I don't use Windows myself, so I do not know if/when it uses generic USB CDC ACM drivers for a serial port, or if it even has any.)

author: Careless
author_rank: Newbie
timestamp: September 11, 2024, 12:52:30 pm
content: Quote from: Andy Chee on September 10, 2024, 08:26:41 pmI saw that page as well when searching for renaming CP2102. I think that's what I'll use for my project and just rename it using a live Linux environment or a debian VM I've used for other Linux related tasks if it detects the USB device correctly. Shouldn't be an issue with the instructions on the webpage.Quote from: Nominal Animal on September 10, 2024, 10:45:18 pmThe micro I'll be using has specific features which are not present on micros with native USB that I am familiar with. Adding a USB controller is trivial, all things considered. I just think it would be neat to name the device appropriately.

author: tszaboo
author_rank: Super Contributor
timestamp: September 11, 2024, 03:17:09 pm
content: Quote from: ataradov on October 31, 2022, 05:06:12 amI genuinely don't know why they don't use the standards that were made to accommodate this.And then we end up with bllsht like early CH340 drivers BSOD-ing your PC.Just use the standard.

author: Kleinstein
author_rank: Super Contributor
timestamp: September 11, 2024, 03:26:38 pm
content: Quote from: Nominal Animal on September 10, 2024, 10:45:18 pmOne good reason to still use a seprate UART to USB converter is when one wants isolation. Isolation at the UART level is easy (e.g. 2 x 6N137).

author: spostma
author_rank: Regular Contributor
timestamp: September 13, 2024, 05:00:03 pm
content: attached is an overview with all WCH USB UART chips.I would select one that has CDC driver, Internal USB config EEPROM, built-in clock, 3rd generation or newer.

author: coppice
author_rank: Super Contributor
timestamp: September 13, 2024, 05:06:54 pm
content: Quote from: JustMeHere on January 17, 2024, 02:47:14 amI had to specially install a Windows driver for something with a CP2102 inside it a few months ago.

author: coppice
author_rank: Super Contributor
timestamp: September 13, 2024, 05:12:51 pm
content: Quote from: tszaboo on September 11, 2024, 03:17:09 pmThe early USB specifications tended to focus on things nobody really wanted to do, like feeding a telecoms T1/E1 PRI into a plesiochronous USB port, and missed the key things USB was really going to be heavily used for. So, the serial spec appeared after a lot of USB silicon development was underway. Somehow after that hardly anyone took the standardised mode of operation seriously. If you consider how long it took for sales of USB products to take off, this is really quite odd.

author: ataradov
author_rank: Super Contributor
timestamp: September 13, 2024, 05:16:36 pm
content: This was certainly true for FTDI, since their first chips preceded the USB spec. But the only real reason they are still doing that is vendor lock in, plus the deal with MS to bundle the drivers.But WCH 100% designed their ICs after the spec was well established, so there is no excuse to not use CDC.

author: Nominal Animal
author_rank: Super Contributor
timestamp: September 13, 2024, 06:40:46 pm
content: I really likeTI ISO7721for UART isolation (TX and RX signals only, no power), as they work up to very high baud rates, only draw a few milliamps at most, and provide logic level voltage translation, so the other side may use any logic level and supply between 2.25V and 5.5V. JLCPCB currently sells ISO7721DR (SO-8) for 0.39€ and ISO7721DWR (SO-16 300mil) for 0.77€ apiece for PCB assembly; LCSC for 0.41€ and 0.81€ in singles, Mouser for 1.66€ and 2€ in singles, respectively. Just add a 100nF supply bypass capacitor on each side. The working isolation voltage range is about 450 VAC RMS, i.e. sufficient between different types of mains power supplies (grounded and ungrounded).For longer runs, and when crossing mains domains (different breaker panels), optoisolation is still better.Also, note that plain USB CDC ACM does not support end-to-end RTS/CTS flow control. Simply put, there is no provision for monitoring or configuring CTS behaviour.