For anyone having issues with their Duplex MMDVM hotspot, this is a just a quick post about using a Duplex MMDVM hotspot in Simplex mode.
When I first received my hotspot, I had a lot of problems getting it to work correctly. Some of these have now been resolved, thanks to the work of Andy CA6JAU, making changes to his firmware.
Nevertheless, it can be handy for testing, to initially run the hotspot in Simplex mode..
Unfortunately just selecting Simplex from the Controller Type does not work.
Changing to Simplex Node removes the separate Transmitter and Receiver frequency boxes in the General Configuration, and replaces it with a single “Radio Frequency”.
The trick to use your Duplex hotspot as a Simplex hotspot is to select the MMDVM_HS_Hat rather than MMDVM_HS_Dual_Hat
In this mode the SMA socket labelled Rx on some boards and AE1 on others, is now the one that will be used.
In my case I connected this to my external antenna, but you could just use one of the cheap 10cm long antennas which are supplied with these sorts of boards.
And the board works just fine !