MOD-RS232 with flow control

[bertpeeters]

Hi all,

I have connected my A20 to an external RS232 device using the MOD-RS232 on one of the UEXT connectors. I use the http://code.google.com/p/android-serialport-api/ for communication. However, I cannot write to / read from the device. If I try and repeat the read/write, only on some rare occasions some text commands can be communicated.

The RS232 device, according to the manual, requires RTS/CTS flow control, which is something the MOD-RS232 doesn't have. So I guess that could be the problem.

Can you guys think of a solution? Could I build my own RS232-UEXT or RS232-GPIO module that does incorporate flow control?

[bertpeeters]

Okay, it seems I misinterpreted the default MOD-RS232 Rx/Tx jumper configuration in combination with the null modem cable I used. I switched to a straight through cable, thus switching the Rx and Tx. Now it works.

I did, however, also loop back the CTS and RTS pins on the RS232 device connector, to trick the devices hardware control. Don't know if that's necessary, though.