feature: Add dummy mode

ardriver/xreal/xrealsrc/FusionOffset.c

@@ -0,0 +1,77 @@
+/**
+ * @file FusionOffset.c
+ * @author Seb Madgwick
+ * @brief Gyroscope offset correction algorithm for run-time calibration of the
+ * gyroscope offset.
+ */
+
+//------------------------------------------------------------------------------
+// Includes
+
+#include "FusionOffset.h"
+#include <math.h>
+
+//------------------------------------------------------------------------------
+// Definitions
+
+/**
+ * @brief Cutoff frequency in Hz.
+ */
+#define CUTOFF_FREQUENCY (0.02f)
+
+/**
+ * @brief Timeout in seconds.
+ */
+#define TIMEOUT (5)
+
+/**
+ * @brief Threshold in degrees per second.
+ */
+#define THRESHOLD (3.0f)
+
+//------------------------------------------------------------------------------
+// Functions
+
+/**
+ * @brief Initialises the gyroscope offset algorithm.
+ * @param offset Gyroscope offset algorithm structure.
+ * @param sampleRate Sample rate in Hz.
+ */
+void FusionOffsetInitialise(FusionOffset *const offset, const unsigned int sampleRate) {
+    offset->filterCoefficient = 2.0f * (float) M_PI * CUTOFF_FREQUENCY * (1.0f / (float) sampleRate);
+    offset->timeout = TIMEOUT * sampleRate;
+    offset->timer = 0;
+    offset->gyroscopeOffset = FUSION_VECTOR_ZERO;
+}
+
+/**
+ * @brief Updates the gyroscope offset algorithm and returns the corrected
+ * gyroscope measurement.
+ * @param offset Gyroscope offset algorithm structure.
+ * @param gyroscope Gyroscope measurement in degrees per second.
+ * @return Corrected gyroscope measurement in degrees per second.
+ */
+FusionVector FusionOffsetUpdate(FusionOffset *const offset, FusionVector gyroscope) {
+
+    // Subtract offset from gyroscope measurement
+    gyroscope = FusionVectorSubtract(gyroscope, offset->gyroscopeOffset);
+
+    // Reset timer if gyroscope not stationary
+    if ((fabsf(gyroscope.axis.x) > THRESHOLD) || (fabsf(gyroscope.axis.y) > THRESHOLD) || (fabsf(gyroscope.axis.z) > THRESHOLD)) {
+        offset->timer = 0;
+        return gyroscope;
+    }
+
+    // Increment timer while gyroscope stationary
+    if (offset->timer < offset->timeout) {
+        offset->timer++;
+        return gyroscope;
+    }
+
+    // Adjust offset if timer has elapsed
+    offset->gyroscopeOffset = FusionVectorAdd(offset->gyroscopeOffset, FusionVectorMultiplyScalar(gyroscope, offset->filterCoefficient));
+    return gyroscope;
+}
+
+//------------------------------------------------------------------------------
+// End of file