So I had my Arduino Due based MMDVM up and running on the hill top and wanted to upload new firmware to it without driving 30km up to the repeater site. The Raspberry Pi3 it is connected to is completely headless, no desktop, no vnc … only ssh. I tried stuff like forwarding the serial port over TCP, but no joy.
Introduction I came across a Motorola R100 repeater, those were very capable low to mid duty repeaters in the late 80s up to the 21st century, yet some of them are still in commercial use. What follows is more or less a memo on how I converted it for digital use and eventually analog/digital use. I got awesome results in DStar, pretty good results in DMR but Fusion is not so good as I did not have a Fusion radio to test. There is a huge amount of information available online, especially on Repeater Builder they even have information on DStar interfacing but the latter did not work for me. What follows applies to the UHF variant of the repeater, for VHF your mileage may vary. This worked for me and might not work for your particular case.