Merge pull request #61 from BarryPSmith/sx1262_paclamping

Implemented TX PA Clamping, datasheet section 15.2

src/modules/SX1262.cpp

@@ -22,6 +22,11 @@ int16_t SX1262::begin(float freq, float bw, uint8_t sf, uint8_t cr, uint16_t syn
     return(state);
   }
 
+  state = SX126x::fixPaClamping();
+  if (state != ERR_NONE) {
+    return state;
+  }
+
   return(state);
 }
 
@@ -43,6 +48,11 @@ int16_t SX1262::beginFSK(float freq, float br, float freqDev, float rxBw, int8_t
     return(state);
   }
 
+  state = SX126x::fixPaClamping();
+  if (state != ERR_NONE) {
+    return state;
+  }
+
   return(state);
 }
 

src/modules/SX1262.h

@@ -92,8 +92,6 @@ class SX1262: public SX126x {
     int16_t setOutputPower(int8_t power);
 
   private:
-
-
 };
 
 #endif

src/modules/SX1268.cpp

@@ -22,6 +22,11 @@ int16_t SX1268::begin(float freq, float bw, uint8_t sf, uint8_t cr, uint16_t syn
     return(state);
   }
 
+  state = SX126x::fixPaClamping();
+  if (state != ERR_NONE) {
+    return state;
+  }
+
   return(state);
 }
 int16_t SX1268::beginFSK(float freq, float br, float freqDev, float rxBw, int8_t power, float currentLimit, uint16_t preambleLength, float dataShaping) {
@@ -42,6 +47,11 @@ int16_t SX1268::beginFSK(float freq, float br, float freqDev, float rxBw, int8_t
     return(state);
   }
 
+  state = SX126x::fixPaClamping();
+  if (state != ERR_NONE) {
+    return state;
+  }
+
   return(state);
 }
 

src/modules/SX126x.cpp

@@ -1199,6 +1199,16 @@ int16_t SX126x::setFrequencyRaw(float freq) {
   return(ERR_NONE);
 }
 
+int16_t SX126x::fixPaClamping() {
+  uint8_t clampConfig;
+  uint16_t state = readRegister(SX126X_REG_TX_CLAMP_CONFIG, &clampConfig, 1);
+  if (state != ERR_NONE) {
+    return state;
+  }
+  clampConfig |= 0x1E;
+  return writeRegister(SX126X_REG_TX_CLAMP_CONFIG, &clampConfig, 1);
+}
+
 int16_t SX126x::config(uint8_t modem) {
   // set regulator mode
   uint8_t data[7];

src/modules/SX126x.h

@@ -92,6 +92,7 @@
 #define SX126X_REG_OCP_CONFIGURATION                  0x08E7
 #define SX126X_REG_XTA_TRIM                           0x0911
 #define SX126X_REG_XTB_TRIM                           0x0912
+#define SX126X_REG_TX_CLAMP_CONFIG                    0x08D8 //Datasheet 15.2
 
 
 // SX126X SPI command variables
@@ -753,6 +754,10 @@ class SX126x: public PhysicalLayer {
 
     int16_t setFrequencyRaw(float freq);
 
+    /*!
+      \brief Fixes overly eager PA clamping on SX1262 / SX1268, as described in section 15.2 of the datasheet
+    */
+    int16_t fixPaClamping();
   private:
     Module* _mod;
 
@@ -769,6 +774,8 @@ class SX126x: public PhysicalLayer {
 
     int16_t config(uint8_t modem);
 
+
+
     // common low-level SPI interface
     int16_t SPIwriteCommand(uint8_t cmd, uint8_t* data, uint8_t numBytes, bool waitForBusy = true);
     int16_t SPIwriteCommand(uint8_t* cmd, uint8_t cmdLen, uint8_t* data, uint8_t numBytes, bool waitForBusy = true);