add feature send battery voltage data

include/globals.h

@@ -17,7 +17,7 @@
 #define SENSOR1_DATA (0x10)
 #define SENSOR2_DATA (0x20)
 #define SENSOR3_DATA (0x40)
-#define SENSOR4_DATA (0x80)
+#define BATT_DATA (0x80)
 
 // bits in configmask for device runmode control
 #define GPS_MODE (0x01)

include/payload.h

@@ -44,6 +44,7 @@ public:
   void addStatus(uint16_t voltage, uint64_t uptime, float cputemp, uint32_t mem,
                  uint8_t reset1, uint8_t reset2);
   void addAlarm(int8_t rssi, uint8_t message);
+  void addVoltage(uint16_t value);
   void addGPS(gpsStatus_t value);
   void addBME(bmeStatus_t value);
   void addButton(uint8_t value);