Which USB to Serial (TTL) Cable? - Page 1
Forum section: electronics / general

author: MatteoX
author_rank: Regular Contributor
timestamp: March 08, 2019, 04:25:29 am
content: What USB to Serial TTL cables are you guys using/recommending? I have an old FTDI but I will need to get a few more.Ebay has very cheap cables (starting at < $2) that are based mainly on (fake?) Prolific chips. I don't want to pay $15 - $20 / cable but on the other hand it is not worth spending extra time fighting problems.Sparkfun/Adafruit have cables for about $12 but with shipping price almost double (if nothing else is purchased).

author: lty1993
author_rank: Unknown
timestamp: March 08, 2019, 05:42:26 am
content: How about grabbing some cheap Arduino / stm32 dev boards, and flash it with USB CDC firmware.

author: westfw
author_rank: Super Contributor
timestamp: March 08, 2019, 08:35:21 am
content: I rather like these modules, if they have the pins you need:https://www.aliexpress.com/item/1PCS-CH340E-USB-to-TTL-Serial-Converter-5V-3-3V-Universal-Not-need-switching-Model-BTE17/32821571106.html

author: josip
author_rank: Regular Contributor
timestamp: March 08, 2019, 08:38:33 am
content: Quote from: lty1993 on March 08, 2019, 05:42:26 amOr not so cheap Kinetis device with open source solution (http://www.utasker.com/kinetis.html) that can offer 6 CDC - UART bridges.

author: magic
author_rank: Super Contributor
timestamp: March 08, 2019, 01:08:01 pm
content: Fake PL2303HX are OK. I have used them for years at speeds up to a few MBaud and also with CTS/RTS flow control. No problems so far. Sourced them from Polish importers and AliExpress vendors who received positive feedback for those exact products.You won't find genuine Prolific on auction sites, they boast on their website about only selling to big name consumer product vendors so that customers can be sure they are getting the real thingBeware that many eBay modules run the serial interface at 5V for some mysterious reason, though the chip has an integrated 3.3V LDO and should be ran at 3.3V.Beware that those with crystals are the older A revision, sometimes called HXA, which has been blocked by Windows drivers in W8 and W10. Both fakes and reals are blocked. The newer, crystalless HXD/rev.D work on Windows too.update: PL2303TA also uses crystals and is still supported.Except for the driver drama they are the superior UART as far as I'm concerned, although you may not care about any of that:- separate voltage supply for the serial interface- proper, fast-acting hardware flow control, which immediately elevates them above FTDI- flexible baud rate generator, capable of producing anything from 75Baud to 6MBaud with apparently better than 1% resolution

author: MatteoX
author_rank: Regular Contributor
timestamp: March 08, 2019, 04:22:09 pm
content: Quote from: lty1993 on March 08, 2019, 05:42:26 amI would prefer having it in the form of cable. If I put (another) board on a crowded bench I have to be careful that it does not get shorted on some peace of metal or make a box

author: MatteoX
author_rank: Regular Contributor
timestamp: March 08, 2019, 04:30:05 pm
content: Quote from: westfw on March 08, 2019, 08:35:21 amThis one looks nice. It also has handshaking signals that I don't need now but may be useful in future. Have you perhaps seen this type of devices packaged? Otherwise I would need to be very careful that the board does not short on something, my bench is usually full of stuff.

author: wraper
author_rank: Unknown
timestamp: March 08, 2019, 04:44:51 pm
content: You can simply buy cp2102 or CH340 based converter.

author: MatteoX
author_rank: Regular Contributor
timestamp: March 08, 2019, 04:48:40 pm
content: Quote from: magic on March 08, 2019, 01:08:01 pmHow do I distinguish between crystal/no crystal versions if I buy "smart" cable version, i.e. with electronics integrated in the usb connector? Ebay sellers usually don't provide much description.

author: MatteoX
author_rank: Regular Contributor
timestamp: March 08, 2019, 04:58:22 pm
content: Quote from: wraper on March 08, 2019, 04:44:51 pmIs there any preference between cp2102 or CH340 regarding driver quality on Windows 10 and Linux? I am currently working on Windows 10 but I am also planing also to use these converters on a Linux system.

author: coromonadalix
author_rank: Super Contributor
timestamp: March 08, 2019, 08:20:36 pm
content: If its possible try to find a genuine ftdi serial cable, works very well, never drop data etc .... yeah i know about the ftdi gate, drivers horrors stories etc etc ... i wont go thereYou have ch340 cables who work well tooAnd finally : yes you have counterfeit FTDI and Prolific cables, i`ve tried yesterday to help my friend to install a fake prolific cable, never worked in the end, even with a supposed hacked driver to help, removed all drivers traces, cleaned registry ... never worked.The fakes FTDI who get jammed by certain drivers version can be put back to work again with a ftdi software ``FTDI Prog``, you write back the vid / pid infos, but you have to use an old driver version ... the drivers test the eeprom content and size of the ftdi and if its not a genuine one, it will overwrite it, and windows wont find the cable .. unlees you use ftdi prog.There is a ton of fakes around, arduinos and many other pcb`s and or cables, the list goes on and on and on.Invest in a good cable ... for all my projects i use genuine ftdi or ch340, tossed the prolific ...I have marked my fake ftdi cables, i use them regularly up to 115200 bauds with no problems BUT i block all the drivers update in windows and use a lower driver version, 2.08 i think was the last version without the genuine check

author: magic
author_rank: Super Contributor
timestamp: March 08, 2019, 11:10:12 pm
content: Quote from: MatteoX on March 08, 2019, 04:48:40 pmI would be looking for advertised Windows 8 support, preferably confirmed by buyer feedback.IIRC, that's how I chose where to buy my (bare) PL2303HXD chips and they turned out to work without crystals and support Windows 10.As for my adapters, I have two small boards with rev.A using crystals and running at 5V, I'm sure you have seen such boards, one modded to 3.3V by me. I use Linux so no driver nonsense here. I also have an HX rev.A cellphone cable (Nokia DKU-5 clone) reterminated to BLS, probably unobtainium these days, and another two cellphone cables with certainly fake HX rev.C, a Windows-friendly chip discontinued looooong ago and totally unobtainium.I had a look at Ali, it seems that as far as cables go, PL2303TA is all the rage these days. A very similar chip to2303HXD2303HXA, I don't even know what the difference is, still supported on Windows. But, I have no idea what I/O voltage these cables use and when Prolific will discontinue support for the TATruth be told, if you really care about Windows, you may want to stay with that 340 thing or whatever. I have heard they work on Linux too, at least basic TX/RX.

author: coromonadalix
author_rank: Super Contributor
timestamp: March 09, 2019, 01:31:54 am
content: windows 8 was the last best windows for many projects, win 8.1 begin to ask for signed drivers etc ...... a pain in the ........ unless you hack the drivers signature enforcement blah blah

author: lucazader
author_rank: Regular Contributor
timestamp: March 10, 2019, 03:27:52 am
content: I have used quite a lot of different chips.Genuine FTDI, fake fdi CH340, cp2012 genuine, cp2012 fake, stm32 bluepill flashed with cdc firmware.Here are my observations:Most work fine if all you need is up to 512k baud. Especially on windows.cp2012 wont work on windows above 921600.Also tested most on linux. while mostly the behavior is the same, some chips can go faster on linuxI find the CH340 and the Flashed stm32 bluepills work best when going over this baud rate, especially if you go to around 2M baud.The Bluepills can do 3 uarts on a single board, but its annoying trying to figure out which pin is tx and rx, and corresponds to which virtual port on the PC.As of lately i have found some really good ch340's and never skip a beat and am pretty happy with.

author: Deepak
author_rank: Regular Contributor
timestamp: March 10, 2019, 03:47:41 am
content: I've had luck with thesehttps://www.amazon.com/JANSANE-PL2303TA-Serial-Console-Raspberry/dp/B07D9R5JFK/ref=cm_cr_arp_d_product_top?ie=UTF8Not sure if they're real Prolific chips, but they've served their job so far.

author: magic
author_rank: Super Contributor
timestamp: March 10, 2019, 09:19:46 am
content: Probably fakes, I wonder if it's same as similar $1 cables on eBay and Ali or maybe a special order with genuine chips? One can dreamIs the red cable 5V? What's the IO voltage?

author: legacy
author_rank: Super Contributor
timestamp: March 10, 2019, 09:36:04 am
content: for a project, I need a four UART-ports (TTL) to USB. Is there anything that you recommend?the maximal baud rate on each port is 115200bps, and we I do not need CTS/RTS&C

author: coromonadalix
author_rank: Super Contributor
timestamp: March 10, 2019, 09:49:54 am
content: we use this one at my shop : 22$made by Adafruit Industries LLChttps://www.digikey.ca/product-detail/en/adafruit-industries-llc/18/1528-1115-ND/5353575never failed ??They have a buffer chip between the ftdi and the rs232 plug, we can left it connected to our boards, others adapters dont ...

author: legacy
author_rank: Super Contributor
timestamp: March 10, 2019, 10:02:48 am
content: what do you think aboutCY7C65213? There is a Sparkfun breakout around.

author: coromonadalix
author_rank: Super Contributor
timestamp: March 10, 2019, 10:04:05 am
content: https://www.ebay.com/itm/USB-UART-Serial-Breakout-Board-CY7C65213/123662927541?hash=item1ccae286b5:g:dp4AAOSw4plcc0s8https://www.sparkfun.com/products/13830DescriptionDesigned to provide users with a means to access all available I/O pins on the ICProvides a 6-pin UART headerCompatible with other SparkFun breakout boardsEquipped with a micro-B USB portThe USB UART Serial Breakout Board - CY7C65213 is designed to provide users with a means to access all available I/O pins on the IC, and to provide a 6-pin UART header that is compatible with other SparkFun breakout boards. This breakout has a microUSB connector and other support circuitry to get the IC quickly up and running. The CY7C65213 breakout is equipped with a micro-B USB port, USB signal lines, a VIO selection jumper, a low-voltage selection jumper, and a multitude of pins that allow you to utilize the board to its fullest potential. The CY7C65213 breakout is capable of operating at both 3V and 5V based on what the VIO selection jumper is set to. Additionally this breakout can operate at 2V and below.and a video :Never saw any kind of cable, but they where put in some programmers. I dont know the Windows or any other Os'es compatibility ??

author: Deepak
author_rank: Regular Contributor
timestamp: March 10, 2019, 11:39:00 am
content: Quote from: magic on March 10, 2019, 09:19:46 amProbably the same, but I was able to get them without waiting for the shipping time from China. Red Is 5v and i/o reads ~3.3vQuote from: coromonadalix on March 10, 2019, 09:49:54 amThat's an Rs232 cable and will blow the ass out of a TTL device. DB9 connectors are no guarantee of compatibility.

author: josip
author_rank: Regular Contributor
timestamp: March 10, 2019, 06:28:38 pm
content: Quote from: legacy on March 10, 2019, 09:36:04 amXR21V1414 and XR21B1424 (https://www.maxlinear.com/products/interface/uarts/usb-uarts) both in DIY friendly QFP.I don't have link right know (to nxp/kinetis community page), where Mark Butcher write about his open source (for non-professional use) utasker where K22 is used as 6 channel CDC bridge.

author: westfw
author_rank: Super Contributor
timestamp: March 11, 2019, 01:42:33 am
content: (BTW, I sort-of put FTDI and Prolific in the same category of "broke existing products; might be worth avoiding." FTDI did it by explicitly detecting and bricking or refusing to operate with counterfeit chips that no one knew they had, while Prolific just decided to discontinue new OS support for their older chip family (that also happened to be widely cloned.) Best hardware or no, I'm not happy with either of them.)

author: stj
author_rank: Super Contributor
timestamp: March 11, 2019, 07:10:48 am
content: i like these - very high quality build.ignore the "only one left" rubbish - seller has been saying that for atleast a year!https://www.ebay.co.uk/itm/201704657786

author: legacy
author_rank: Super Contributor
timestamp: March 11, 2019, 10:44:23 am
content: Quote from: coromonadalix on March 10, 2019, 10:04:05 amyup, there is an SDK for Linux, but no feedbacks about it

author: legacy
author_rank: Super Contributor
timestamp: March 11, 2019, 06:05:45 pm
content: there is also thecp2108chip, and around a USB card with 4 ports TTL UART.