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Topic: Real FTDI Breakout vs. Cheap Chinese USB to Serial TTL (Read 22897 times) previous topic - next topic

DrWizard

I bought a cheap Chinese USB to Serial TTL adapter for $1 off of the popular e-auction site, thinking it was the same thing as a FTDI breakout board and that I could use it as such.  Part of my reasoning was that I knew that "FTDI" simply stood for the name of the company that makes the USB serial chips.

Well it turns out I was wrong, I can't seem to get the Chinese one to work (Has anyone had any success with them?) so I guess I wasted a dollar.  Boo hoo.

FYI: the Chinese one uses a counterfeit clone of the Prolific PL2303 chip, and does not work with the current version of the Prolific driver, but does work with the older 2004 driver for Vista.  I verified it is actually working by shorting the TXD to RXD pins as a loopback, and typing into a terminal program and my characters get echoed back, and the TXD and RXD status lights flash.  The Chinese one does not have a DTR output to connect to the Arduino and thus reset it as it is about to upload the sketch, but I tried the pressing and holding the reset button on the Arduino and releasing it as the sketch finishes compiling and starts to upload, but could not get the sketch to upload, kept getting the avrdude not in sync error.  Tried varying my timing without success.

Lesson learned: Spend a few extra bucks for a real FTDI breakout board.

Paul__B


Part of my reasoning was that I knew that "FTDI" simply stood for the name of the company that makes the USB serial chips.

And indeed that is the case.


Well it turns out I was wrong, I can't seem to get the Chinese one to work (Has anyone had any success with them?) so I guess I wasted a dollar.  Boo hoo.

Sour grapes.  They work just fine for me.  If you bought one for a dollar, then it will be a five-pin version which does not provide for the extra control line.  Unfortunately it is the case that the six pin versions were produced by someone who had no idea whatsoever what he was doing and brought out the wrong pin.  They can however be modified to work perfectly well.


FYI: the Chinese one uses a counterfeit clone of the Prolific PL2303 chip, and does not work with the current version of the Prolific driver, but does work with the older 2004 driver for Vista.  I verified it is actually working by shorting the TXD to RXD pins as a loopback, and typing into a terminal program and my characters get echoed back, and the TXD and RXD status lights flash.

So it would appear you do have the correct driver.


The Chinese one does not have a DTR output to connect to the Arduino and thus reset it as it is about to upload the sketch, but I tried the pressing and holding the reset button on the Arduino and releasing it as the sketch finishes compiling and starts to upload, but could not get the sketch to upload, kept getting the avrdude not in sync error.  Tried varying my timing without success.

You most likely have the TXD and RXD pins swapped incorrectly.  This is the most common - and simplest error.  I presume you are using it with a "Pro Mini".  Once you get it right, it will work with the correct timing.  Do not press the reset too quickly after the "Binary sketch size" message appears, about one second seems to be near the mark.  Do not press it until that message appears, just causes finger fatigue; just press it briefly.  Windoze appears to be significantly slower than Linux.


Lesson learned: Spend a few extra bucks for a real FTDI breakout board.

Only if you are averse to real experimentation, that is.  :D

Docedison

And it only takes a steady hand and a good soldering iron and the operator 's skills to make PL2303 a real USB to serial adapter. DTR is marked on the data sheet for the PL2303 just extend it, remove the 5 pin header and replace it with a 6 pin (I use stacking headers). Solder the DTR wire to this pin. As to counterfeit, No... more likely it is the version for which that driver was written for. Superseded IC's aren't necessarily destroyed... I'd bet a careful inspection of the chip numbering might solve this.. Issue.

Doc
--> WA7EMS <--
"The solution of every problem is another problem." -Johann Wolfgang von Goethe
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john1993

#3
Sep 22, 2013, 02:31 am Last Edit: Sep 22, 2013, 02:38 am by john1993 Reason: 1
ive done as "doc" describes to many many (many) of those $1 adapters and they do an excellent job. it only takes a minute to swap pin 2 of the chip to one of the unused connectors (5v in my case because im exclusively 3.3v) and they work fine for arduino. the $2 dongles are somewhat easier because the dtr signal is available on a thru-hole. and they are silabs based instead of ftdi which have some advantages.

p.s. if you use a .1 cap with 10k pullup instead of a piece of wire then the arduino ide can load bare chips instead of requiring a uno or other pricey pcb. for me it is silly to put ftdi circuit on every board when most final applications do not need a usb interface. imo better to put it on the cable/dongle.

Zapro

As to counterfeit, No... more likely it is the version for which that driver was written for. Superseded IC's aren't necessarily destroyed... I'd bet a careful inspection of the chip numbering might solve this.. Issue.


PL2303 has been on the market for over 15 years, and have been cloned, and the clone isn't working very well. The genuine chips works with all versions of the drivers on all supported OS'es without any issues.

Also, the PL2303 is not available as a bare die to any customer, so it's quite obvious when you have a clone in your hands.

http://phsorx.blogspot.dk/2011/11/usb-20-to-rs232-serial-cable.html

// Per.

fungus



Part of my reasoning was that I knew that "FTDI" simply stood for the name of the company that makes the USB serial chips.

And indeed that is the case.


Well it turns out I was wrong, I can't seem to get the Chinese one to work (Has anyone had any success with them?) so I guess I wasted a dollar.  Boo hoo.

Sour grapes.  They work just fine for me. 


Me too.

Take a really hard look at the pinouts marked on the board. Don't assume the chips are on top, some of them need to be flipped over to work.
No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

kecso

I also bought a cheap chinese Prolific clone. (Note I'm using OSX Yosemite)
First I tried to use with an old prolific driver, breakout recognized as PL2303-###### not even the loopback test was working. Than I installed the latest official Prolific driver (http://www.prolific.com.tw/US/ShowProduct.aspx?p_id=229&pcid=41) and since than it works fine (recognized as USBSerial).

Paul__B

So - the driver has been upgraded in order to work properly with clones?  :smiley-eek:

ChilliTronix

I still prefer the CH340 USB to serial boards...

arduino5

Is this a genuine?

http://www.ebay.com/itm/PL2303-USB-To-RS232-TTL-to-RS232-Converter-usb-ttl-converter-Module/370668480977?rt=nc

bobcousins

Is this a genuine?

http://www.ebay.com/itm/PL2303-USB-To-RS232-TTL-to-RS232-Converter-usb-ttl-converter-Module/370668480977?rt=nc
It would seem highly likely to be fake, given this notice Warning Letter on Counterfeit Products
Please ask questions in the forum so everyone can benefit. PM me for paid work.

arduino5

Thx! Will buy an original. To much risks with the low ones.

larryd

No technical PMs.
If you are asked a question, please respond with an answer.
If you are asked for more information, please supply it.
If you need clarification, ask for help.

Paul__B

Thx! Will buy an original. To much risks with the low ones.
Actually, negligible risk

Most of us, and most of the purchasers of huge numbers of the one you cite, have had no trouble at all with the PL2303 devices, "real" or "counterfeit", whatever that means - which is very hard to determine.

bobcousins

FYI on FTDI counterfeits:
https://www.youtube.com/watch?v=eU66as4Bbds&app=desktop

Old news now, FTDI have withdrawn their toxic driver.

The funny thing is that the people who are boycotting FTDI, are probably the people who were buying counterfeit chips (and had them bricked). So basically their boycott is to stop buying counterfeit chips... which is actually what FTDI wanted in the first place!

Legit companies buy through authorised sources, so it's really not an issue for them. People who are buying the cheap stuff off ebay, dx or aliexpress will probably end up buying counterfeit chips, but with another name on.
Please ask questions in the forum so everyone can benefit. PM me for paid work.

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