USB To Serial Converter Cable Question - Page 1
Forum section: electronics / projects

author: Lance
author_rank: Frequent Contributor
timestamp: March 06, 2012, 12:01:02 am
content: I have a USB to serial converter cable by some random company called Nosna. Has anyone ever used stuff by this company before? I'm extremely skeptical of this company, I can find very few references to them, and I've heard plenty of stories of nasty malware being packaged with the drivers from random chinese companies.

author: McMonster
author_rank: Frequent Contributor
timestamp: March 06, 2012, 12:16:05 am
content: The question is what's the chip inside this converter? If it's a popular one, like FT232, then there shouldn't be problems.

author: Lance
author_rank: Frequent Contributor
timestamp: March 06, 2012, 12:38:28 am
content: I can't tell, it's a sealed cable. Not sure how to get it open.

author: Lance
author_rank: Frequent Contributor
timestamp: March 06, 2012, 12:47:14 am
content: Here's a link to the product, although it was purchased at a physical store:http://www.globalcoast.ca/store/index.php?main_page=product_info&products_id=301

author: Bored@Work
author_rank: Super Contributor
timestamp: March 06, 2012, 12:54:22 am
content: Don't open it. Connect it and see what driver is loaded for it, or whats its USB descriptor contains (Windows: usbview; Linux: lsusb).

author: T4P
author_rank: Super Contributor
timestamp: March 06, 2012, 10:20:47 am
content: My USB to Serial Converter based off FT232RL and when loaded just says USB <-> Serial

author: Unknown
author_rank: Unknown
timestamp: March 06, 2012, 10:29:38 am
content: That's what the driver reports, not the vendor/product id as would be reported by usbview or lsusb. In usbview, search for idVendor and idProduct. Looking at the name of the driver in device manager might also give something like 'ftdibus.sys', which would suggest an FTDI part.

author: metalphreak
author_rank: Frequent Contributor
timestamp: March 06, 2012, 11:02:16 am
content: There's quite a few no-brand ones that use the "HL-341" drivers.

author: Lance
author_rank: Frequent Contributor
timestamp: March 06, 2012, 02:46:16 pm
content: I connected it, and Windows enumerated it as a USB-Serial Controller. I'm not sure how to find the USB descriptor. Windows couldn't find any drivers for it.

author: AlphZeta
author_rank: Regular Contributor
timestamp: March 09, 2012, 08:16:21 pm
content: Not sure about Windows, but if you have a Linux machine, you can plug in the device and type lsusb in the console to get the ID information.

author: sacherjj
author_rank: Frequent Contributor
timestamp: March 09, 2012, 08:29:25 pm
content: Quote from: AlphZeta on March 09, 2012, 08:16:21 pmThis can be the easiest way, even if you need to boot a machine into a LiveCD instance of Linux.

author: Bored@Work
author_rank: Super Contributor
timestamp: March 09, 2012, 08:34:42 pm
content: Quote from: AlphZeta on March 09, 2012, 08:16:21 pmThat was already suggested, even with the Windows equivalent. The original poster did give a fucking fart about that suggestion.

author: Lance
author_rank: Frequent Contributor
timestamp: April 08, 2012, 03:56:50 pm
content: Quote from: AlphZeta on March 09, 2012, 08:16:21 pmSorry it took so long to get back, I've been busy.lsusb had the following item of interest in it:Bus 005 Device 003: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port

author: free_electron
author_rank: Super Contributor
timestamp: April 08, 2012, 05:28:09 pm
content: ahh. the prolific crap... that chip has 'issues' ...

author: G7PSK
author_rank: Super Contributor
timestamp: April 08, 2012, 05:56:07 pm
content: Most of the ones I have seen use the Prolific PL3303 usb-serial drivers that also seem to be a common driver for video usb converters used for transcribing vhs onto computers as well.

author: Bored@Work
author_rank: Super Contributor
timestamp: April 08, 2012, 06:52:17 pm
content: The chip works quite fine and the Linux drivers for Prolific usually work. On Windows 50% of the time the drivers are crap and the newer the drivers are the more fucked-up they typically are.

author: ejeffrey
author_rank: Super Contributor
timestamp: April 08, 2012, 06:59:25 pm
content: Most of the common dirt-cheap USB to serial adapters are based off the prolific chips (FTDI being more common when you need multiple ports, extra GPIO, or alternate serial protocols like SPI/JTAG). They work just fine. What is often total crap are the driver CDs that no-name manufacturers ship with them. They work perfectly in Linux (good drivers included in the kernel) and well enough in windows if you download the reference driver from prolific. The PL2303 doesn't have unique device IDs like the FTDI chips, so they can't support persistent device names (i.e., always enumerate as COM6).Many people will warn you that some of these devices have TTL logic levels instead of the standard +/- ~9V RS232 levels. They do this to save the cost of the charge pump to generate the negative voltage from the +5V USB. This is horrible and wrong. I have personally never seen such a device except for something like a dedicated PDA adapter where presumably the manufacturer knows it works with the device in question. Still, it pays to watch out for it if you can't figure out why something doesn't work.

author: Lance
author_rank: Frequent Contributor
timestamp: April 08, 2012, 10:07:12 pm
content: Windows hasn't been able to find the driver for it. I'm going to get the one from the prolific website. It looks pretty tacky...http://www.prolific.com.tw/eng/downloads.asp?ID=31I was able to get at it with Putty in Linux without issues, so if all else fails I can use it there.

author: sonicj
author_rank: Frequent Contributor
timestamp: April 09, 2012, 02:37:41 am
content: Quote from: Lance on April 08, 2012, 10:07:12 pmTheir site does kinda have that early 2000s homebrew look to it.... Regardless of appearance, I have yet to have any trouble with the drivers provided by Prolific.-sj

author: Lance
author_rank: Frequent Contributor
timestamp: April 09, 2012, 02:42:09 am
content: Quote from: sonicj on April 09, 2012, 02:37:41 amI'll give it a try sometime soon then.

author: westfw
author_rank: Super Contributor
timestamp: April 09, 2012, 06:10:45 am
content: >> the prolific crap... that chip has 'issues' ...I've heard that the prolific chips are fine, but that their chip is frequently cloned/pirated/gray-marketed. So your "prolific USB/Serial adapter" may or may not have a real prolific chip that may or may not work with the real Prolific drivers.Prolific is sort-of the generic "consumer" USB/Serial adapter chip, a lot of "brand name" adapters use it (cellphones, GPSs, and etc as well as general purpose adapters.)

author: amyk
author_rank: Super Contributor
timestamp: April 09, 2012, 08:37:03 am
content: Fake PL2303s discussed here before:https://www.eevblog.com/forum/product-reviews-photos-and-discussion/note-how-to-not-get-scammed-with-prolific-(pl2303)-usb-serial-adapters/One of the main ways of verifying that it's fake (or factory reject dies) is if it's a COB and not SOP/QFN, because they don't sell bare die PL2303.

author: Kilroy
author_rank: Regular Contributor
timestamp: April 09, 2012, 01:34:42 pm
content: Based on my experience, if you want anything approaching reliable comms using a USB to serial interface, you should just pick up a Tripp Lite Keyspan USA-19HS and get on with your life.Really though, if you are going to be doing lots of serial comms stuff, I would stay old school and not bother with interface conversions. It's frustrating when a conversion interface cocks up your work flow when everything else is going great.

author: ejeffrey
author_rank: Super Contributor
timestamp: April 09, 2012, 01:57:48 pm
content: Quote from: Kilroy on April 09, 2012, 01:34:42 pmOnce you exhaust the lone COM port you are lucky to have on a computer sold within the last 5 years, you have no choice. Even a PCI card operating as an ISA compatible interface is not quite the same, and in any case is limited to 4 possible ports. If you want more than that, you need some sort of media converter. USB to serial is not ideal, but it is closer to to transparent than any of the alternatives. Honestly, a working PL2303 or an FTDI chip using the VCP drivers gives you essentially perfect emulation from the standpoint of a user-mode windows application. The latency is considerably higher, but windows doesn't give you guaranteed latency even with a hardware port. This isn't a problem if you are doing normal serial communication, but will totally hose you if you want to bit-bang a different protocol on the control lines. The solution is to not do that. Use a microcontroller to implement the interface and use the serial port to send commands to the micro.

author: Unknown
author_rank: Unknown
timestamp: April 09, 2012, 02:06:27 pm
content: What controller does the Tripp Lite use?In my experience PL2303-based USB to serial tend to work just fine for many applications. I even got them to work with Fluke RS-232-IR adapters that draw power from the handshaking lines. Don't expect them to work with bit-banging or applications requiring more than the bare basics of the RS-232 spec. The random COM port assignment in Windows can be a problem, and I've also had issues with occasional hangs in Windows (unplugging and replugging would fix it).I like the PCI/PC-Card RS-232 interfaces much better for critical work. I've had good luck with Quatech PC-Card RS-232 interfaces, although they were expensive ($100+). Be careful with ExpressCard, this bus also contains a USB interface, so ExpressCards may also be USB-serial adapters in disguise.I still use USB to RS-232 interfaces for hobby use, however. They are much more convenient and much cheaper.

author: Kilroy
author_rank: Regular Contributor
timestamp: April 09, 2012, 03:19:50 pm
content: Quote from: alm on April 09, 2012, 02:06:27 pmGood question, alm.Actually, you've got me curious about this. I'm actually looking at my USA-19HS right now, and....I think I might be able to safely spudge this puppy apart for a bit of a look see. I'll let you know what I find.

author: Kilroy
author_rank: Regular Contributor
timestamp: April 09, 2012, 03:44:36 pm
content: Got it...the main USB>serial converter controller IC is a Texas Instruments TUSB3410.And...the RS-232 line driver IC is a Texas Instruments MAX3243EC.Looks like all good stuff in here...and I managed not to wreck the enclosure in the name of science.

author: T4P
author_rank: Super Contributor
timestamp: April 09, 2012, 03:47:25 pm
content: Quote from: alm on April 09, 2012, 02:06:27 pmIt's tough to find a old laptop with a PC Card unless i look to the T61 , nevertheless my usb to serial does everything , bit banging and the like and yet ?Mine's using a chip from Analog Devices , AD213 and that's the only thing i can find , it's a encased type device . ( I took some time to see the part number )

author: Kilroy
author_rank: Regular Contributor
timestamp: April 09, 2012, 04:27:06 pm
content: Quote from: ejeffrey on April 09, 2012, 01:57:48 pmTotally agree with you.Actually, for a great all in one tool for serial/parallel comm work I use A21 and T30 Thinkpads. They work great for all my work a day electronics, data logging, CPLD, MCU programming, PLC, CNC comms and programming...and the list goes on. They are rugged, reliable, modular, have quality components and are nice and snappy on a tuned XP Pro install. Extremely versatile, useful computer for all things electronics...and you should be able to pick one up for the price of a Tripp Lite USA-19HS if you keep an eye out. Also, best keyboard feel ever for when you have a lot of HDL or C to hammer out.QuoteRight, again.In the end, I think it's more comfortable sticking with the hardware. Sure, it's not perfect, but bit banging inevitably distracts the processor, which is never ideal from an efficiency stand point.

author: westfw
author_rank: Super Contributor
timestamp: April 10, 2012, 07:46:36 am
content: >> the main USB>serial converter controller IC is a Texas Instruments TUSB3410.Which frequently has downloadable firmware contained in the driver, making any device using it even more dependent on the driver than normal. For instance, there have been a fair number of problems using the TI-provided "CDC/ACM" firmware (as used on the various TI eval boards) with non-Windows systems.(A lot of otherwise reasonable chip vendors seem to neglect the non-Windows environments. FTDI is doing a REALLY GOOD JOB, imo. Prolific, OTOH, is common enough that the OS vendors support IT. if you get a real chip, anyway.)

author: Lance
author_rank: Frequent Contributor
timestamp: May 07, 2012, 10:59:14 pm
content: How about Microchip brand stuff? Anyone had any experience with their RS232 to USB converter hardware?

author: gxti
author_rank: Frequent Contributor
timestamp: May 08, 2012, 07:23:29 pm
content: Microchip's MCP2200 works great, the only downside compared to FTDI parts is that it requires an external oscillator.