[SX127x] add getTempRaw method

Signed-off-by: gozu42 <tvguho-tbmh42-tct.76b2756e@hashmail.org>

keywords.txt

@@ -126,6 +126,7 @@ setRSSIConfig	KEYWORD2
 setEncoding	KEYWORD2
 getIRQFlags	KEYWORD2
 getModemStatus	KEYWORD2
+getTempRaw	KEYWORD2
 
 # RF69-specific
 setAESKey	KEYWORD2

src/modules/SX127x/SX127x.cpp

@@ -934,6 +934,58 @@ uint8_t SX127x::getModemStatus() {
   return(_mod->SPIreadRegister(SX127X_REG_MODEM_STAT));
 }
 
+int8_t SX127x::getTempRaw() {
+  int8_t temp = 0;
+  uint8_t previousOpMode;
+  uint8_t ival;
+
+  // save current Op Mode
+  previousOpMode = _mod->SPIgetRegValue(SX127X_REG_OP_MODE);
+
+  // check if we need to step out of LoRa mode first
+  if ((previousOpMode & SX127X_LORA) == SX127X_LORA) {
+    _mod->SPIsetRegValue(SX127X_REG_OP_MODE, (SX127X_LORA | SX127X_SLEEP));
+  }
+
+  // put device in FSK sleep
+  _mod->SPIsetRegValue(SX127X_REG_OP_MODE, (SX127X_FSK_OOK | SX127X_SLEEP));
+
+  // put device in FSK RxSynth
+  _mod->SPIsetRegValue(SX127X_REG_OP_MODE, (SX127X_FSK_OOK | SX127X_FSRX));
+
+  // enable temperature reading
+  _mod->SPIsetRegValue(SX127X_REG_IMAGE_CAL, SX127X_TEMP_MONITOR_ON, 0, 0);
+
+  // wait
+  delayMicroseconds(200);
+
+  // disable temperature reading
+  _mod->SPIsetRegValue(SX127X_REG_IMAGE_CAL, SX127X_TEMP_MONITOR_OFF, 0, 0);
+
+  // put device in FSK sleep
+  _mod->SPIsetRegValue(SX127X_REG_OP_MODE, (SX127X_FSK_OOK | SX127X_SLEEP));
+
+  // read temperature
+  ival = _mod->SPIgetRegValue(SX127X_REG_TEMP);
+
+  // convert very raw value
+  if ((ival & 0x80) == 0x80) {
+    temp = 255 - ival;
+  } else {
+    temp = -1 * ival;
+  }
+
+  // check if we need to step back into LoRa mode
+  if ((previousOpMode & SX127X_LORA) == SX127X_LORA) {
+    _mod->SPIsetRegValue(SX127X_REG_OP_MODE, (SX127X_LORA | SX127X_SLEEP));
+  }
+
+  // reload previous Op Mode
+  _mod->SPIsetRegValue(SX127X_REG_OP_MODE, previousOpMode);
+
+  return(temp);
+}
+
 int16_t SX127x::config() {
   // turn off frequency hopping
   int16_t state = _mod->SPIsetRegValue(SX127X_REG_HOP_PERIOD, SX127X_HOP_PERIOD_OFF);

src/modules/SX127x/SX127x.h

@@ -459,8 +459,8 @@
 #define SX127X_TEMP_THRESHOLD_10_DEG_C                0b00000010  //  2     1                                   10 deg. C (default)
 #define SX127X_TEMP_THRESHOLD_15_DEG_C                0b00000100  //  2     1                                   15 deg. C
 #define SX127X_TEMP_THRESHOLD_20_DEG_C                0b00000110  //  2     1                                   20 deg. C
-#define SX127X_TEMP_MONITOR_OFF                       0b00000000  //  0     0     temperature monitoring disabled (default)
-#define SX127X_TEMP_MONITOR_ON                        0b00000001  //  0     0     temperature monitoring enabled
+#define SX127X_TEMP_MONITOR_ON                        0b00000000  //  0     0     temperature monitoring enabled (default)
+#define SX127X_TEMP_MONITOR_OFF                       0b00000001  //  0     0     temperature monitoring disabled
 
 // SX127X_REG_LOW_BAT
 #define SX127X_LOW_BAT_OFF                            0b00000000  //  3     3     low battery detector disabled
@@ -913,6 +913,13 @@ class SX127x: public PhysicalLayer {
     */
     uint8_t getModemStatus();
 
+    /*!
+      \brief Reads uncalibrated temperature value.
+
+      \returns Uncalibrated temperature sensor reading.
+    */
+    int8_t getTempRaw();
+
     #ifdef RADIOLIB_DEBUG
       void regDump();
     #endif