compass: add MAG debug mode for raw magnetometer logging

docs/Blackbox.md

@@ -185,6 +185,7 @@ Available debug modes include:
 - `POS_EST` - Position estimation debugging
 - `GPS` - GPS debugging
 - `ALTITUDE` - Altitude estimation debugging
+- `MAG` - Raw, uncalibrated magnetometer samples (useful for external compass calibration)
 - And 20+ other modes for specific subsystems
 
 To use debug mode logging:

docs/Settings.md

@@ -796,10 +796,12 @@ Defines debug values exposed in debug variables (developer / debugging setting)
 | LULU |  |
 | SBUS2 |  |
 | OSD_REFRESH |  |
+| MAG_CALIB |  |
 | VTOL_TRANSITION |  |
 | VTOL_MC_PROTECT |  |
 | TERRAIN_NAV |  |
 | ESC |  |
+| MAG |  |
 
 ---
 

src/main/build/debug.h

@@ -85,6 +85,7 @@ typedef enum {
     DEBUG_VTOL_MC_PROTECT,
     DEBUG_TERRAIN_NAV,
     DEBUG_ESC,
+    DEBUG_MAG,
     DEBUG_COUNT // also update debugModeNames in cli.c
 } debugType_e;
 

src/main/drivers/compass/compass_mlx90393.c

@@ -105,7 +105,9 @@ static bool mlx90393Read(magDev_t * mag)
 
     uint8_t buf[7] = {0};
 
-    busReadBuf(mag->busDev, MLX90393_READ_MEASUREMENT | MLX90393_MEASURE_3D, buf, 7);
+    if (!busReadBuf(mag->busDev, MLX90393_READ_MEASUREMENT | MLX90393_MEASURE_3D, buf, sizeof(buf))) {
+        return false;
+    }
 
     mag->magADCRaw[X] = ((short)(buf[1] << 8 | buf[2]));
     mag->magADCRaw[Y] = ((short)(buf[3] << 8 | buf[4]));

src/main/fc/cli.c

@@ -235,7 +235,8 @@ static const char *debugModeNames[DEBUG_COUNT] = {
     "VTOL_TRANSITION",
     "VTOL_MC_PROTECT",
     "TERRAIN_NAV",
-    "ESC"
+    "ESC",
+    "MAG"
 };
 
 /* Sensor names (used in lookup tables for *_hardware settings and in status

src/main/fc/settings.yaml

@@ -84,7 +84,8 @@ tables:
       "VIBE", "CRUISE", "REM_FLIGHT_TIME", "SMARTAUDIO", "ACC",
       "NAV_YAW", "PCF8574", "DYN_GYRO_LPF", "AUTOLEVEL", "ALTITUDE",
       "AUTOTRIM", "AUTOTUNE", "RATE_DYNAMICS", "LANDING", "POS_EST",
-      "ADAPTIVE_FILTER", "HEADTRACKER", "GPS", "LULU", "SBUS2", "OSD_REFRESH", "VTOL_TRANSITION", "VTOL_MC_PROTECT", "TERRAIN_NAV", "ESC"]
+      "ADAPTIVE_FILTER", "HEADTRACKER", "GPS", "LULU", "SBUS2", "OSD_REFRESH",
+      "MAG_CALIB", "VTOL_TRANSITION", "VTOL_MC_PROTECT", "TERRAIN_NAV", "ESC", "MAG"]
   - name: vtol_mc_protection_mode
     values: ["OFF", "NAV", "NAV_AND_STABILIZED"]
   - name: aux_operator

src/main/sensors/compass.c

@@ -467,6 +467,7 @@ void compassUpdate(timeUs_t currentTimeUs)
 
     for (int axis = 0; axis < XYZ_AXIS_COUNT; axis++) {
         mag.magADC[axis] = mag.dev.magADCRaw[axis];  // int32_t copy to work with
+        DEBUG_SET(DEBUG_MAG, axis, mag.dev.magADCRaw[axis]);
     }
 
     if (STATE(CALIBRATE_MAG)) {