diff --git a/libraries/AP_Frsky_Telem/AP_Frsky_Backend.h b/libraries/AP_Frsky_Telem/AP_Frsky_Backend.h
index e986aee5d6..e14c2ed190 100644
--- a/libraries/AP_Frsky_Telem/AP_Frsky_Backend.h
+++ b/libraries/AP_Frsky_Telem/AP_Frsky_Backend.h
@@ -3,53 +3,6 @@
 #include <AP_HAL/AP_HAL.h>
 #include <GCS_MAVLink/GCS_MAVLink.h>
 
-/* 
-for FrSky D protocol (D-receivers)
-*/
-// FrSky sensor hub data IDs
-#define DATA_ID_GPS_ALT_BP          0x01
-#define DATA_ID_TEMP1               0x02
-#define DATA_ID_FUEL                0x04
-#define DATA_ID_TEMP2               0x05
-#define DATA_ID_GPS_ALT_AP          0x09
-#define DATA_ID_BARO_ALT_BP         0x10
-#define DATA_ID_GPS_SPEED_BP        0x11
-#define DATA_ID_GPS_LONG_BP         0x12
-#define DATA_ID_GPS_LAT_BP          0x13
-#define DATA_ID_GPS_COURS_BP        0x14
-#define DATA_ID_GPS_SPEED_AP        0x19
-#define DATA_ID_GPS_LONG_AP         0x1A
-#define DATA_ID_GPS_LAT_AP          0x1B
-#define DATA_ID_BARO_ALT_AP         0x21
-#define DATA_ID_GPS_LONG_EW         0x22
-#define DATA_ID_GPS_LAT_NS          0x23
-#define DATA_ID_CURRENT             0x28
-#define DATA_ID_VARIO               0x30
-#define DATA_ID_VFAS                0x39
-
-#define START_STOP_D                0x5E
-#define BYTESTUFF_D                 0x5D
-
-/* 
-for FrSky SPort and SPort Passthrough (OpenTX) protocols (X-receivers)
-*/
-// FrSky Sensor IDs
-#define SENSOR_ID_VARIO             0x00 // Sensor ID  0
-#define SENSOR_ID_FAS               0x22 // Sensor ID  2
-#define SENSOR_ID_GPS               0x83 // Sensor ID  3
-#define SENSOR_ID_SP2UR             0xC6 // Sensor ID  6
-#define SENSOR_ID_27                0x1B // Sensor ID 27
-
-// FrSky data IDs
-#define GPS_LONG_LATI_FIRST_ID      0x0800
-#define DIY_FIRST_ID                0x5000
-
-#define FRAME_HEAD                  0x7E
-#define FRAME_DLE                   0x7D
-#define FRAME_XOR                   0x20
-
-#define SPORT_DATA_FRAME            0x10
-
 class AP_Frsky_Backend {
 public:
 
@@ -102,6 +55,50 @@ protected:
         uint16_t yaw;
     } _SPort_data;
 
+    /*
+      for FrSky D protocol (D-receivers)
+    */
+    // FrSky sensor hub data IDs
+    static const uint8_t DATA_ID_GPS_ALT_BP        = 0x01;
+    static const uint8_t DATA_ID_TEMP1             = 0x02;
+    static const uint8_t DATA_ID_FUEL              = 0x04;
+    static const uint8_t DATA_ID_TEMP2             = 0x05;
+    static const uint8_t DATA_ID_GPS_ALT_AP        = 0x09;
+    static const uint8_t DATA_ID_BARO_ALT_BP       = 0x10;
+    static const uint8_t DATA_ID_GPS_SPEED_BP      = 0x11;
+    static const uint8_t DATA_ID_GPS_LONG_BP       = 0x12;
+    static const uint8_t DATA_ID_GPS_LAT_BP        = 0x13;
+    static const uint8_t DATA_ID_GPS_COURS_BP      = 0x14;
+    static const uint8_t DATA_ID_GPS_SPEED_AP      = 0x19;
+    static const uint8_t DATA_ID_GPS_LONG_AP       = 0x1A;
+    static const uint8_t DATA_ID_GPS_LAT_AP        = 0x1B;
+    static const uint8_t DATA_ID_BARO_ALT_AP       = 0x21;
+    static const uint8_t DATA_ID_GPS_LONG_EW       = 0x22;
+    static const uint8_t DATA_ID_GPS_LAT_NS        = 0x23;
+    static const uint8_t DATA_ID_CURRENT           = 0x28;
+    static const uint8_t DATA_ID_VARIO             = 0x30;
+    static const uint8_t DATA_ID_VFAS              = 0x39;
+
+    static const uint8_t START_STOP_D              = 0x5E;
+    static const uint8_t BYTESTUFF_D               = 0x5D;
+
+    // FrSky data IDs;
+    static const uint16_t GPS_LONG_LATI_FIRST_ID    = 0x0800;
+    static const uint16_t DIY_FIRST_ID              = 0x5000;
+
+    static const uint8_t FRAME_HEAD                = 0x7E;
+    static const uint8_t FRAME_DLE                 = 0x7D;
+    static const uint8_t FRAME_XOR                 = 0x20;
+
+    static const uint8_t SPORT_DATA_FRAME          = 0x10;
+
+    // for FrSky SPort and SPort Passthrough (OpenTX) protocols (X-receivers)
+    static const uint8_t SENSOR_ID_VARIO           = 0x00; // Sensor ID  0
+    static const uint8_t SENSOR_ID_FAS             = 0x22; // Sensor ID  2
+    static const uint8_t SENSOR_ID_GPS             = 0x83; // Sensor ID  3
+    static const uint8_t SENSOR_ID_SP2UR           = 0xC6; // Sensor ID  6
+    static const uint8_t SENSOR_ID_27              = 0x1B; // Sensor ID 27
+
 private:
 
     void loop(void);