If the Raspberry fails to connect the hotspot board, please try update the firmware of the hotspot board by conducting the command: sudo pistar-mmdvmhshatflash hs_hat. More info pls view amateurradionotes.com/pi-star-notes.htm#hotspotfwupdate.
Compatible with P4 settings:
Method 1: Remove the R1 resistance of the hotspot board(single/dual) ;
Method 2: Cut off the 2 Raspberry Pi pin headers on the corners of the board ( pick one to operate on your MMDVM board, refer to the product image for the R1 and 2 pin headers locations)
Features
High efficiency, less power comsumption, High quality TCXO, stable, low BER
Support Raspberry Pi 3B, 3B +, Pi ZERO, compatible with NanoPi NEO, Orange Pi, compatible with BlueDV (requires USBtoTTL or Bluetooth model)
Support MMDVM mode DMR / YSF / P25 / NXDN / DSTAR / POCSAG
Support online upgrade, User-friendly OLED and Nextion special design location, reserved for additional installation of Bluetooth modules

Package List
1x MMDVM motherboard(UHF/VHF)