Diff: source/drivers/MicroBitAccelerometer.cpp

Revision:

65:f7ebabf23e15

Parent:

56:1311cac15dda

--- a/source/drivers/MicroBitAccelerometer.cpp	Wed Jul 13 12:18:43 2016 +0100
+++ b/source/drivers/MicroBitAccelerometer.cpp	Wed Jul 13 12:18:45 2016 +0100
@@ -348,23 +348,43 @@
         shake.z = !shake.z;
     }
 
-    if (shakeDetected && shake.count < MICROBIT_ACCELEROMETER_SHAKE_COUNT_THRESHOLD && ++shake.count == MICROBIT_ACCELEROMETER_SHAKE_COUNT_THRESHOLD)
-        shake.shaken = 1;
-
-    if (++shake.timer >= MICROBIT_ACCELEROMETER_SHAKE_DAMPING)
+    // If we detected a zero crossing in this sample period, count this.
+    if (shakeDetected && shake.count < MICROBIT_ACCELEROMETER_SHAKE_COUNT_THRESHOLD)
     {
-        shake.timer = 0;
-        if (shake.count > 0)
+        shake.count++;
+  
+        if (shake.count == 1)
+            shake.timer = 0;
+
+        if (shake.count == MICROBIT_ACCELEROMETER_SHAKE_COUNT_THRESHOLD)
         {
-            if(--shake.count == 0)
-                shake.shaken = 0;
+            shake.shaken = 1;
+            shake.timer = 0;
+            return MICROBIT_ACCELEROMETER_EVT_SHAKE;
         }
     }
 
-    // Shake events take the highest priority, as under high levels of change, other events
-    // are likely to be transient.
-    if (shake.shaken)
-        return MICROBIT_ACCELEROMETER_EVT_SHAKE;
+    // measure how long we have been detecting a SHAKE event.
+    if (shake.count > 0)
+    {
+        shake.timer++;
+
+        // If we've issued a SHAKE event already, and sufficient time has assed, allow another SHAKE event to be issued.
+        if (shake.shaken && shake.timer >= MICROBIT_ACCELEROMETER_SHAKE_RTX)
+        {
+            shake.shaken = 0;
+            shake.timer = 0;
+            shake.count = 0;
+        }
+
+        // Decay our count of zero crossings over time. We don't want them to accumulate if the user performs slow moving motions.
+        else if (!shake.shaken && shake.timer >= MICROBIT_ACCELEROMETER_SHAKE_DAMPING)
+        {
+            shake.timer = 0;
+            if (shake.count > 0)
+                shake.count--;
+        }
+    }
 
     if (instantaneousAccelerationSquared() < MICROBIT_ACCELEROMETER_FREEFALL_THRESHOLD)
         return MICROBIT_ACCELEROMETER_EVT_FREEFALL;
@@ -433,6 +453,12 @@
     // Determine what it looks like we're doing based on the latest sample...
     uint16_t g = instantaneousPosture();
 
+    if (g == MICROBIT_ACCELEROMETER_EVT_SHAKE)
+    {
+        MicroBitEvent e(MICROBIT_ID_GESTURE, MICROBIT_ACCELEROMETER_EVT_SHAKE);
+        return;
+    }
+
     // Perform some low pass filtering to reduce jitter from any detected effects
     if (g == currentGesture)
     {