Diff: process_data.cpp

Revision:

8:8430a5c0914c

Child:

9:a711b5b34d73

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/process_data.cpp	Tue May 20 00:43:55 2014 +0000
@@ -0,0 +1,128 @@
+#include "mbed.h"
+#include "process_data.h"
+#include "SystemTime.h"
+#include "debug.h"
+
+int window = 0;
+int16_t *history;
+int16_t prev_data = 0;
+
+Timer split_timer;
+
+/* Initializes the moving average with a window size */
+bool process_init()
+{
+    window = WINDOW_SIZE;
+    history = new int16_t[WINDOW_SIZE](); // initializes to 0
+
+    split_timer.start();
+    return true;
+}
+
+/* Will break for window size > 2^8
+ * Returns a moving average for data
+ * Returns INT16_MAX until it has received a window
+ * size worth of data. These values should be ignored. */
+int16_t mov_avg(int16_t data)
+{
+    static uint8_t front = 0, end_ = 0, count = 0;
+    static int32_t total;
+
+    if (count < window-1) {
+        history[end_] = data;
+        end_ = end_ + 1;
+        count = count + 1;
+        return INT16_MAX;
+    } else if (count == window-1) {
+        history[end_] = data;
+        for (int i = 0; i <= count; i++)
+            total = total + history[i];
+        count = count + 1;
+        end_ = 0;
+        front = 1;
+        prev_data = history[0];
+        return INT16_MAX;
+    } else {
+        history[end_] = data;
+        total = total - prev_data + data;
+        end_ = end_ + 1;
+        front = front + 1;
+
+        if (end_ >= window)
+            end_ = 0;
+
+        if (front >= window)
+            front = 0;
+
+        if (front == 0)
+            prev_data = history[window-1];
+        else {
+            prev_data = history[front - 1];
+        }
+
+        return total/window;
+    }
+}
+
+/* Returns true if there is a peak (flip turn) */
+bool peak_detect(int16_t data)
+{
+    static uint8_t i = 0;
+    static int16_t avg[3];
+
+    int16_t m = mov_avg(data);
+
+    if (m == INT16_MAX)
+        return false;
+
+    if (i < 3) {
+        avg[i++] = m;
+        return false;
+    }
+
+    avg[0] = avg[1];
+    avg[1] = avg[2];
+    avg[2] = m;
+
+    if ( (avg[0] > avg[1]) && (avg[2] > avg[1]) && (avg[2] < -2000) && (avg[1] < -2000) && (avg[0] < -2000) ) {
+        PC_PRINTLNF("Peak detected @ %d", split_timer.read_ms());
+        return true;
+    }
+
+    return false;
+}
+
+enum length {ZERO, ONE, TWO};
+
+/* Returns split time, or UINT16_MAX if not on a split */
+uint16_t process_data(int16_t data)
+{
+    static enum length Length = ZERO;
+    static int l_zero, l_two;
+
+    if (peak_detect(data)) {
+        if (Length == ZERO) {
+            l_zero = split_timer.read_ms();
+            Length = ONE;
+            return UINT16_MAX;
+        } else if (Length == ONE) {
+//            l_one = SystemTime::read_ms();
+            Length = TWO;
+            return UINT16_MAX;
+        } else {
+            l_two = split_timer.read_ms();
+            Length = ZERO;
+            split_timer.reset();
+            return ( abs((l_two - l_zero)));
+        }
+    }
+    
+    return UINT16_MAX;
+}
+
+bool process_close() {
+    delete(history);
+    split_timer.reset();
+    split_timer.stop();
+    return true;
+}
\ No newline at end of file