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Topic: Programming an UNO clone using a FTDI cable (Read 2 times) previous topic - next topic

oric_dan

One thing about the FTDI cable that nobody mentioned is it uses RTS instead of DTR.
The FTDI Friend [similar 6-pin female header I/F] uses DTR, however. Also, both of
these come in 5V and 3.3V versions.

For the cable, you need to go to "Control Panel > System > Hardware > device manager"
for the comport, and select "set RTS on close".


danomahoney

#11
Jan 14, 2013, 11:36 am Last Edit: Jan 14, 2013, 11:55 am by danomahoney Reason: 1
Hi Fokes,

I've checked all the usual TX/RX reversal, 5V or 3.3V, RTS, DTR, board type and auto reset hardware, havn't got to the root cause yet, but going back to an older bootloader does work.  I do think it is related to reset, and as some has suggested try a manual reset, however I found it very difficult to get the timing correct for it the work.

I have come to this conclusion because I an able to program an Arduino Mini Pro 5V with the FTDI lead and b'board, I checked the b'loader version on said Mini Pro using a sketch, reprogrammed the clone with the same b'loader and it works reliably.

So I'm convinced it's b'loader based, may be the root is due to some acknowledgement signal or timing etc. It seems that OPTIbootloaded and the FTDI Chip are not compatible, (handshaking etc, hardware is not a problem). The UNO uses a 8U2 device with a build-in USB controller. If someone is interested in using a clone UNO I would suggest buying a, https://www.sparkfun.com/products/10277, a 8U2 b'board, this should work without problems.

When I have time I will investigate further, may even buy the above.

ATB Dan, living and learning:-)

retrolefty


Hi Fokes,

I've checked all the usual TX/RX reversal, 5V or 3.3V, RTS, DTR, board type and auto reset hardware, havn't got to the root cause yet, but going back to an older bootloader does work.  I do think it is related to reset, and as some has suggested try a manual reset, however I found it very difficult to get the timing correct for it the work.

The easiest way to perform a manual reset that I was told about and tried is to press and hold down the reset button, then press upload, and when you see the first blink on the USB serial recieve LED release the reset button. That works pretty reliably for me.

I have come to this conclusion because I an able to program an Arduino Mini Pro 5V with the FTDI lead and b'board, I checked the b'loader version on said Mini Pro using a sketch, reprogrammed the clone with the same b'loader and it works reliably.

So I'm convinced it's b'loader based, may be the root is due to some acknowledgement signal or timing etc. It seems that OPTIbootloaded and the FTDI Chip are not compatible, (handshaking etc, hardware is not a problem). The UNO uses a 8U2 device with a build-in USB controller. If someone is interested in using a clone UNO I would suggest buying a, https://www.sparkfun.com/products/10277, a 8U2 b'board, this should work without problems.

Well I have installed the Uno optibootloader on all my 328 based boards, including older ones having a on-board FTDI chip and all works well as long as I remember to select Uno as the board type. Again the bootloader has no knowledge by what means the serial data is getting to pins 0 and 1, just that the programming data is coming at the correct baudrate from the IDE/AVRDUDE.

Lefty


When I have time I will investigate further, may even buy the above.

ATB Dan, living and learning:-)

westfw

It's vaguely possible, given the serial speeds involved, that SOME FTDI adapters might not work with SOME arduino clones using optiboot.   The 115200bps serial rate used by optiboot is not particularly accurate on a 16MHz AVR.  If (say) neither the AVR nor the FTDI had a crystal-controlled clock it's possible that you could get "unlucky" to the point where they could not reliably communicate.

oric_dan

Quote
It seems that OPTIbootloaded and the FTDI Chip are not compatible, (handshaking etc, hardware is not a problem).


99% of the time, I use either the FTDI cable or the FTDI Friend, both of which use FTDI chips,
and they work with both 16Mhz optiboot [UNO] and Duemilanove bootloader chips. So the issue
isn't one of compatibility.

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