+#define to_fix16(x) ((int16_t) ((x) * 65536.0 + 0.5))
+#define to_fix32(x) ((int32_t) ((x) * 65536.0 + 0.5))
+#define from_fix(x) ((x) >> 16)
+
+/*
+ * Above this height, the baro sensor doesn't work
+ */
+#define AO_MAX_BARO_HEIGHT 12000
+#define AO_BARO_SATURATE 13000
+#define AO_MIN_BARO_VALUE ao_altitude_to_pres(AO_BARO_SATURATE)
+
+/*
+ * Above this speed, baro measurements are unreliable
+ */
+#define AO_MAX_BARO_SPEED 200
+
+#define ACCEL_NOSE_UP (ao_accel_2g >> 2)
+