Use of Moteino FTDI header pins 2 and 6 in programming interface cable

[RLP]

Hi - I have purchased a Moteino R3 and I have a question about the FTDI USB/Serial programming cable.  I currently have a Silicon Labs CP210x USB/Serial compatible product that does not have DTR, RTS, and CTS in the cable interface.  I checked the Moteino schematic for the FTDI cable header and made a custom crossover short cable to connect it to the Moteino R3 that looks like this:

Moteino      SiliconLabs
FTDI            USB/Serial
Connector   Connector
-----------------------------
3 PWR    ---       +5V
1 GND    ---       GND
5 TX       ---       RX
4 RX       ---       TX
6 RST                     (not connected)
2                            (not connected)

The upload appears to start ok, then hangs near the progress bar end.  BTW the default blink program on the Moteino appears to be continuously running.
Is it not ok to have Moteino FTDI pins 2 and 6 floating, or is this Silicon Labs device just incompatible?

Thanks!

[Felix]

Pin 2 in not connected on the Moteino, it's only there to make it compatible with most 6pin header FTDI adapters.
On the FTDI adapter side, pin 2 is CTS, and pin 6 is RTS by default and can be switched to DTR if you cut/resolder a jumper pad on the back (see product page for details).

To program Moteinos you will need to reset the target to put it in bootloader mode. The FTDI adapter does that using pin 6 (RTS or DTR). If you don't have that function on your other serial adapter, then you can do it manually but have to be quick, right after you press UPLOAD in the IDE. Otherwise the Moteino will never reset and the IDE will keep waiting until it will finally fail with some unintuitive error message.

Hope this helps...

[RLP]

Thanks much for your prompt reply.  This is very helpful.  So I must temporarily, and very quickly, ground pin 6 (DTR) on the Moteino FTDI header immediately after the IDE upload command, correct?  I'll give it a try.  I am also ordering one of the FTDI cables you recommend that provides that control RTS pin.

Since I ordered the R3 with flash, which I understand is preloaded with the bootloader, I'll also look into using wireless programming per your link.

Thanks again!

[Felix]

Yes, short the Moteino RST or the FTDI header DTR to GND very quickly after you click UPLOAD.
Good luck with your project!

[RLP]

Will do.  Thanks much!