I have a baofeng DMR radio with SMS feature, and since there is not much DMR radio owners in my area I want to do something myself.
The easiest thing I can do I thought is to send myself some SMS as I did with a POCSAG pager using my hackrf one.
But I haven't found any software to do that. All I found is MMDVM-SDR program on github which acts as a MMDVM modem utilizing a fake serial port. It allows to get commands from the MMDVM-Host and modulate them as IQ WAV file.
There is one problem: that MMDVM modem protocol has no commands to send DMR SMS. It only accepts "DMR DATA packet" at different rates. I tried to google for "DMR AIR interface" but it also has no mentions of SMS.
By that time I learned that DMR SMS is a non-standartized thing which leaves me with this questions (one is part of the another):
- What format all those TYT and Baofeng radios is using, where I can get it's datasheet.
- How to make a DMR SMS packet for my radio and send it to a MMDVM modem emulator or directly to the SDR using some other modem software?
PS: I tried to record my radio's signal with SDR and play it back. With voice it works, I can hear myself, but with SMS it doesn't work for some reason: my radio just ignores them (maybe that is because it's number in both from and to fields?)