I have a suggestion for an automatic channel tuning function based on GPS location for STM32 based radios with GPS receivers.
There are similar features implemented in the anytone radios, but they are based on RSSI, which is not a very good indication for DMR signals.
The feature would work as follows:
- create a GPS tuning zone.
- each channel would include a transmitter GPS location, input in CPS, It would also include a radius in km/miles of the transmitter range.
- each channel would include a list of "shadow zones" when the channel transmitter cannot be heard. Each entry would have GPS location and radius. (This is for mountainous regions like Colorado )
- hysteresis for switching channels when overlapping zones
- timer for switching channels when exiting a particular area.( in other words how often we calculate all this. Every 10s 1m 10 m ..etc.)
- keypad mapping to turn auto-tuning on or off.
This is just to seed the idea, i am sure it can be improved.