Change set/get accelerometer and gyro offsets to use floats values

This makes it consistent with other API changes to convert the register
values to floats and vice versa.

Author: sandeepmistry

libraries/CurieIMU/examples/RawImuDataSerial/RawImuDataSerial.ino

@@ -72,12 +72,12 @@ void setup() {
 
     // To manually configure offset compensation values,
     // use the following methods instead of the autoCalibrate...() methods below
-    //CurieIMU.setAccelerometerOffset(X_AXIS,128);
-    //CurieIMU.setAccelerometerOffset(Y_AXIS,-4);
-    //CurieIMU.setAccelerometerOffset(Z_AXIS,127);
-    //CurieIMU.setGyroOffset(X_AXIS,129);
-    //CurieIMU.setGyroOffset(Y_AXIS,-1);
-    //CurieIMU.setGyroOffset(Z_AXIS, 254);
+    //CurieIMU.setAccelerometerOffset(X_AXIS,495.3);
+    //CurieIMU.setAccelerometerOffset(Y_AXIS,-15.6);
+    //CurieIMU.setAccelerometerOffset(Z_AXIS,491.4);
+    //CurieIMU.setGyroOffset(X_AXIS,7.869);
+    //CurieIMU.setGyroOffset(Y_AXIS,-0.061);
+    //CurieIMU.setGyroOffset(Z_AXIS,15.494);
 
     Serial.println("About to calibrate. Make sure your board is stable and upright");
     delay(5000);

libraries/CurieIMU/src/CurieIMU.cpp

@@ -332,53 +332,77 @@ bool CurieIMUClass::accelerometerOffsetEnabled()
     return getAccelOffsetEnabled();
 }
 
-int CurieIMUClass::getGyroOffset(int axis)
+float CurieIMUClass::getGyroOffset(int axis)
 {
+    int bmiOffset;
+
     if (axis == X_AXIS) {
-        return getXGyroOffset();
+        bmiOffset = getXGyroOffset();
     } else if (axis == Y_AXIS) {
-        return getYGyroOffset();
+        bmiOffset = getYGyroOffset();
     } else if (axis == Z_AXIS) {
-        return getZGyroOffset();
+        bmiOffset = getZGyroOffset();
+    } else {
+        return -1;
     }
 
-    return -1;
+    return (bmiOffset * 0.061);
 }
 
-int CurieIMUClass::getAccelerometerOffset(int axis)
+float CurieIMUClass::getAccelerometerOffset(int axis)
 {
+    int bmiOffset;
+
     if (axis == X_AXIS) {
-        return getXAccelOffset();
+        bmiOffset = getXAccelOffset();
     } else if (axis == Y_AXIS) {
-        return getYAccelOffset();
+        bmiOffset = getYAccelOffset();
     } else if (axis == Z_AXIS) {
-        return getZAccelOffset();
+        bmiOffset = getZAccelOffset();
+    } else {
+        return -1;
     }
 
-    return -1;
+    return (bmiOffset * 3.9);
 }
 
-void CurieIMUClass::setGyroOffset(int axis, int offset)
+void CurieIMUClass::setGyroOffset(int axis, float offset)
 {
+    int bmiOffset = offset / 0.061;
+
+    if (bmiOffset < -512) {
+        bmiOffset = -512;
+    } else if (bmiOffset > 511) {
+        bmiOffset = 511;
+    }
+
     if (axis == X_AXIS) {
-        setXGyroOffset(axis);
+        setXGyroOffset(bmiOffset);
     } else if (axis == Y_AXIS) {
-        setYGyroOffset(axis);
+        setYGyroOffset(bmiOffset);
     } else if (axis == Z_AXIS) {
-        setZGyroOffset(axis);
+        setZGyroOffset(bmiOffset);
     }
 
     setGyroOffsetEnabled(true);
 }
 
-void CurieIMUClass::setAccelerometerOffset(int axis, int offset)
+void CurieIMUClass::setAccelerometerOffset(int axis, float offset)
 {
+    int bmiOffset = offset / 3.9;
+
+    if (bmiOffset < -128) {
+        bmiOffset = -128;
+    } else if (bmiOffset > 127) {
+        bmiOffset = 127;
+    }
+
     if (axis == X_AXIS) {
-        setXAccelOffset(axis);
+        setXAccelOffset(bmiOffset);
     } else if (axis == Y_AXIS) {
-        setYAccelOffset(axis);
+        setYAccelOffset(bmiOffset);
     } else if (axis == Z_AXIS) {
-        setZAccelOffset(axis);
+        setZAccelOffset(bmiOffset);
     }
 
     setAccelOffsetEnabled(true);

libraries/CurieIMU/src/CurieIMU.h

@@ -120,11 +120,14 @@ class CurieIMUClass : public BMI160Class {
         bool gyroOffsetEnabled();
         bool accelerometerOffsetEnabled();
 
-        int getGyroOffset(int axis);
-        int getAccelerometerOffset(int axis);
+        float getGyroOffset(int axis);
+        float getAccelerometerOffset(int axis);
 
-        void setGyroOffset(int axis, int offset);
-        void setAccelerometerOffset(int axis, int offset);
+        // supported values: -31.171 to 31.171 (degrees/second), in steps of 0.061 degrees/second
+        void setGyroOffset(int axis, float offset);
+
+        // supported values: -495.3 (mg) to 495.3 (mg), in steps of 3.9 mg
+        void setAccelerometerOffset(int axis, float offset);
 
         // supported values:
         //   CURIE_IMU_FREEFALL: 3.91 to 1995.46 (mg), in steps of 7.81 mg