This firmware is modified from: https://github.com/tridge/DavisSi1000 to use Australian frequency hops instead of US frequency hops
Frequencies were derived from: https://github.com/dekay/DavisRFM69 and converted as such: freq = (msb << 16 + mid << 8 + lsb) * 61.03515625
Compiled firmware can be downloaded here
3DR radio (and clones) should use radio~hm_trp.ihx
RFD900 radios should use: radio~rfd900a.ihx
Confirmed working with this radio
Not working with this cheaper radio
Windows: For simplicity use ardupilot Mission Planner Select the com port at the top right and set the BAUD to 57600 then, Initial Setup -> Optional Hardware -> Sik Radio and click "Upload Custom Firmware", Select the file when it asks and wait for it to install.
For further information see: https://github.com/tridge/DavisSi1000
Thanks Tridge!