Calibrate configured frequency for AGC reset

Author: weebl2000

src/helpers/radiolib/CustomLR1110.h

@@ -20,6 +20,8 @@ class CustomLR1110 : public LR1110 {
       return len;
     }
 
+    float getFreqMHz() const { return freqMHz; }
+
     bool isReceiving() {
       uint16_t irq = getIrqStatus();
       bool detected = ((irq & RADIOLIB_LR11X0_IRQ_SYNC_WORD_HEADER_VALID) || (irq & RADIOLIB_LR11X0_IRQ_PREAMBLE_DETECTED));

src/helpers/radiolib/CustomLR1110Wrapper.h

@@ -7,7 +7,7 @@
 class CustomLR1110Wrapper : public RadioLibWrapper {
 public:
   CustomLR1110Wrapper(CustomLR1110& radio, mesh::MainBoard& board) : RadioLibWrapper(radio, board) { }
-  void doResetAGC() override { lr11x0ResetAGC((LR11x0 *)_radio); }
+  void doResetAGC() override { lr11x0ResetAGC((LR11x0 *)_radio, ((CustomLR1110 *)_radio)->getFreqMHz()); }
   bool isReceivingPacket() override {
     return ((CustomLR1110 *)_radio)->isReceiving();
   }

src/helpers/radiolib/LR11x0Reset.h

@@ -5,12 +5,16 @@
 // Full receiver reset for LR11x0-family chips (LR1110, LR1120, LR1121).
 // Warm sleep powers down analog, calibrate(0x3F) refreshes all calibration blocks,
 // then re-applies RX settings that calibration may reset.
-inline void lr11x0ResetAGC(LR11x0* radio) {
+inline void lr11x0ResetAGC(LR11x0* radio, float freqMHz) {
   radio->sleep(true, 0);
   radio->standby(RADIOLIB_LR11X0_STANDBY_RC, true);
 
   radio->calibrate(RADIOLIB_LR11X0_CALIBRATE_ALL);
 
+  // calibrate(0x3F) defaults image calibration to an unknown band.
+  // Re-calibrate for the actual operating frequency (band=4MHz matches RadioLib default).
+  radio->calibrateImageRejection(freqMHz - 4.0f, freqMHz + 4.0f);
+
 #ifdef RX_BOOSTED_GAIN
   radio->setRxBoostedGainMode(RX_BOOSTED_GAIN);
 #endif

src/helpers/radiolib/SX126xReset.h

@@ -18,6 +18,10 @@ inline void sx126xResetAGC(SX126x* radio) {
     radio->mod->hal->yield();
   }
 
+  // Calibrate(0x7F) defaults image calibration to 902-928MHz band.
+  // Re-calibrate for the actual operating frequency.
+  radio->calibrateImage(radio->freqMHz);
+
 #ifdef SX126X_DIO2_AS_RF_SWITCH
   radio->setDio2AsRfSwitch(SX126X_DIO2_AS_RF_SWITCH);
 #endif