@ -15,6 +15,7 @@ This software is licenced under the GPL v2 and is intended for amateur and educa
- Status LEDs (PTT, COR and digital modes)
- Serial repeater port for Nextion displays
- Support for native USB port in STM32F103 CPU
- RSSI support
- Full duplex support with two ADF7021 (experimental)
# Important notes
@ -27,6 +28,8 @@ Be aware that some Blue Pill STM32F103 board are defectives. If you have trouble
VHF (144-148 MHz) support for ZUMSpot is added by an external 18 nH inductor between L1 and L2 pins of ADF7021.
Dual ADF7021 for full duplex operation (#define DUPLEX in Config.h) will work only with a big RX/TX frequency separation (5 MHz or more in UHF band for example) and proper antenna filtering. At the moment #define ADF7021_CARRIER_BOARD (Config.h) with STM32F103 platform is supported. Please see BUILD.md for pinout details.
If you can't decode any 4FSK modulation (DMR, YSF and P25) with your ZUMspot, the common solution is to adjust RX frequency offset (RXOffset) in your MMDVM.ini file. Please try with steps of +-100 Hz until you get low BER. If you don't have test equipment, the only procedure is trial and error. In some cases TXOffset adjustment is also required for proper radio decoding.
Andy CA6JAU
9 years ago