Merge pull request #17 from beegee-tokyo/master

Function to set DIO2 of SX126x chips to be used as RF antenna switch

keywords.txt

@@ -104,6 +104,7 @@ setGdo1Action	KEYWORD2
 # SX126x-specific
 setDio2Action	KEYWORD2
 setTCXO	KEYWORD2
+setDio2AsRfSwitch	KEYWORD2
 
 # ESP8266
 join	KEYWORD2

src/TypeDef.h

@@ -461,6 +461,11 @@
 */
 #define ERR_SPI_CMD_FAILED                    -707
 
+/*!
+  \brief SX126x scan channel not possible because DIO2 is used as RF antenna switch.
+*/
+#define ERR_DIO2_UNAVAIL_CAD_FAILED           -708
+
 /*!
   \}
 */

src/modules/ESP8266.cpp

@@ -180,7 +180,7 @@ size_t ESP8266::receive(uint8_t* data, size_t len, uint32_t timeout) {
   return(i);
 }
 
-uint16_t ESP8266::getNumBytes(uint32_t timeout, size_t minBytes) {
+size_t ESP8266::getNumBytes(uint32_t timeout, size_t minBytes) {
   // wait for available data
   uint32_t start = millis();
   while(_mod->ModuleSerial->available() < (int16_t)minBytes) {

src/modules/SX126x.cpp

@@ -33,6 +33,11 @@ int16_t SX126x::begin(float bw, uint8_t sf, uint8_t cr, uint16_t syncWord, uint1
   }
 
   // configure publicly accessible settings
+  state = setDio2AsRfSwitch(false);
+  if(state != ERR_NONE) {
+    return(state);
+  }
+
   state = setSpreadingFactor(sf);
   if(state != ERR_NONE) {
     return(state);
@@ -86,6 +91,11 @@ int16_t SX126x::beginFSK(float br, float freqDev, float rxBw, uint16_t preambleL
   }
 
   // configure publicly accessible settings
+  state = setDio2AsRfSwitch(false);
+  if(state != ERR_NONE) {
+    return(state);
+  }
+
   state = setBitRate(br);
   if(state != ERR_NONE) {
     return(state);
@@ -274,6 +284,11 @@ int16_t SX126x::scanChannel() {
     return(ERR_WRONG_MODEM);
   }
 
+  if (_dio2RfSwitch) {
+    // If DIO2 is used as RF switch this function does not work
+    return(ERR_DIO2_UNAVAIL_CAD_FAILED);
+  }
+
   // set mode to standby
   int16_t state = standby();
   if(state != ERR_NONE) {
@@ -1058,18 +1073,27 @@ int16_t SX126x::setFrequencyRaw(float freq) {
   return(ERR_NONE);
 }
 
-int16_t SX126x::config(uint8_t modem) {
-  // set DIO2 as IRQ
-  uint8_t* data = new uint8_t[1];
-  data[0] = SX126X_DIO2_AS_IRQ;
-  int16_t state = SPIwriteCommand(SX126X_CMD_SET_DIO2_AS_RF_SWITCH_CTRL, data, 1);
-  if(state != ERR_NONE) {
-    return(state);
+int16_t SX126x::setDio2AsRfSwitch(bool enable) {
+  uint8_t data[1];
+  if (enable) {
+  // set DIO2 as RF switch
+    data[0] = SX126X_DIO2_AS_RF_SWITCH;
+  } else {
+    data[0] = SX126X_DIO2_AS_IRQ;
   }
+  int16_t state = SPIwriteCommand(SX126X_CMD_SET_DIO2_AS_RF_SWITCH_CTRL, data, 1);
 
+  if (state == ERR_NONE) {
+    _dio2RfSwitch = enable;
+  }
+  return(state);
+}
+
+int16_t SX126x::config(uint8_t modem) {
   // set regulator mode
+  uint8_t* data = new uint8_t[1];
   data[0] = SX126X_REGULATOR_DC_DC;
-  state = SPIwriteCommand(SX126X_CMD_SET_REGULATOR_MODE, data, 1);
+  int16_t state = SPIwriteCommand(SX126X_CMD_SET_REGULATOR_MODE, data, 1);
   if(state != ERR_NONE) {
     return(state);
   }

src/modules/SX126x.h

@@ -678,6 +678,13 @@ class SX126x: public PhysicalLayer {
     */
     float getSNR();
 
+    /*!
+      \brief Set DIO2 to function as RF switch (default in Semtech example designs).
+
+      \returns \ref status_codes 
+    */
+    int16_t setDio2AsRfSwitch(bool enable = true);
+
   protected:
     // SX1276x SPI command implementations
     int16_t setTx(uint32_t timeout = 0);
@@ -720,6 +727,8 @@ class SX126x: public PhysicalLayer {
 
     float _dataRate;
 
+    bool _dio2RfSwitch = false;
+
     int16_t config(uint8_t modem);
 
     // common low-level SPI interface