CHIRP

On a previous version of Ubuntu (and CHIRP), circa 2014, I managed to program my UV-82 radio with the included programming cable (which is based on something claiming to be a pl2303 chip). However, today I found that I was unable to do so. The cable showed up in dmesg, but plugging the cable into the radio appeared to trip the push-to-talk and make it try to transmit. Attempting to communicate (upload or download) with CHIRP would just produce a "Radio did not respond" error.

Since I previously had it working, I knew the radio and cable were good, so I went digging. I found http://askubuntu.com/q/465628/170317 which suggested that the drivers shipped with non-ancient versions of Ubuntu for the pl2303 chip will default the DTR (Data Terminal Ready) line of the serial interface to logical 0. Ordinarily, this line is always logical 1, and indicates that the computer is ready to communicate. I added some code to the UV-5R driver in CHIRP (which is used by the UV-82) to try and change this, and it seems to work (as long as you wait a bit for the DTR signal to register with the radio and for it to stop trying to transmit).

It looks like really only the sleep is needed (since pyserial sets DTR to 1 by default when it opens the port, and you just have to wait for the radio to notice), but I'm going to submit a patch that makes it explicit that this radio needs DTR=1 in order to work.