altos: Fix TMega v6.0 and v5.0 IMU axes

[fw/altos] / src / telemega-v6.0 / ao_pins.h

diff --git a/src/telemega-v6.0/ao_pins.h b/src/telemega-v6.0/ao_pins.h
index 5bc224fe950ac97dde27ef82c8407537ea4e0d11..2518e6ba45785bae1827d60fbfa0fbc0a26032ac 100644 (file)
--- a/src/telemega-v6.0/ao_pins.h
+++ b/src/telemega-v6.0/ao_pins.h
@@ -327,21 +327,28 @@ struct ao_adc {
 
 /*
  *
- * If the board is laying component side up with
- * the antenna (nose) pointing north
+ * Here are the required sensor signs:
  *
- * +along      north   +roll   left up
- * +across     west    +pitch  nose down
- * +through    up      +yaw    left turn
+ * +along      nose up
+ * +across     USB down
+ * +through    TH down
+ *
+ * With the board aligned to have positive accel for the relevant
+ * axis, looking down from above we have:
+ *
+ * +roll       counter clockwise (nose up)
+ * +pitch      counter clockwise (USB down)
+ * +yaw                counter clockwise (TH down)
  */
 
 /*
- * bmi088
- *
- *     pin 1 NE corner of chip
+ * On TMega v6, bmi088 pin 1 (NE corner of chip) is placed towards the
+ * USB and antenna edges of the board. Relative to bmi088 specs, to
+ * get the above values, we need to flip the Y axis, assigning values
+ * as follows:
  *
- *     +along          +Y      +roll   +Y
- *     +across         -X      +pitch  -X
+ *     +along          +X      +roll   +X
+ *     +across         -Y      +pitch  -Y
  *     +through        +Z      +yaw    +Z
  */
 
@@ -353,12 +360,12 @@ struct ao_adc {
 #define AO_BMI088_GYR_CS_PIN   13
 #define HAS_IMU                        1
 
-#define ao_bmi088_along(m)     ((m)->acc.y)
-#define ao_bmi088_across(m)    (-(m)->acc.x)
+#define ao_bmi088_along(m)     ((m)->acc.x)
+#define ao_bmi088_across(m)    (-(m)->acc.y)
 #define ao_bmi088_through(m)   ((m)->acc.z)
 
-#define ao_bmi088_roll(m)      ((m)->gyr.y)
-#define ao_bmi088_pitch(m)     (-(m)->gyr.x)
+#define ao_bmi088_roll(m)      ((m)->gyr.x)
+#define ao_bmi088_pitch(m)     (-(m)->gyr.y)
 #define ao_bmi088_yaw(m)       ((m)->gyr.z)
 
 #define ao_data_along(packet)  ao_bmi088_along(&(packet)->bmi088)