Diff: main.cpp

Revision:

0:5e7363c894ab

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu Jun 25 08:57:32 2015 +0000
@@ -0,0 +1,78 @@
+#include "mbed.h"
+
+DigitalIn A(D15);
+DigitalIn B(D14);
+PwmOut squareSignal(D10);
+InterruptIn riseEvent(D9);
+Serial pc(USBTX, USBRX);
+Timer displayTimer;
+
+Timer periodTimer;
+Timer freqUpdateTimer;
+float period;
+float generatorPeriod = 1.0e-3f;
+float delta = 50.0e-6f;
+
+void readEncoder();
+void onRisingEdge();
+
+int main()
+{
+    // configuram semnalul dreptunghiular
+    // perioada = 1ms
+    // latimea pulsului = 0.5ms
+    squareSignal.period(generatorPeriod);
+    squareSignal = 0.5f;
+    
+    riseEvent.rise(onRisingEdge);
+    periodTimer.start();
+    
+    displayTimer.start();
+    freqUpdateTimer.start();
+    while (true) {
+        readEncoder();
+        if (displayTimer.read() > 0.5f) {
+            pc.printf("Frequency: %g, period: %g\n", 1.0f / period, period);
+            displayTimer.reset();
+        }
+        if (freqUpdateTimer.read_us() > 1000) {
+            squareSignal.period(generatorPeriod);
+            squareSignal = 0.5f;
+            freqUpdateTimer.reset();
+        }
+    }
+}
+
+void onRisingEdge()
+{
+    period = periodTimer.read();
+    periodTimer.reset();
+}
+
+void readEncoder()
+{
+    static int state = 0;
+    int currentState;
+    const int stateOrder[] = {0, 2, 3, 1};
+    const int stateIndex[] = {0, 3, 1, 2};
+    int ccwState, cwState;
+    
+    currentState = (A << 1) | B;
+    ccwState = stateOrder[(stateIndex[state] + 3) & 3];
+    cwState = stateOrder[(stateIndex[state] + 1) & 3];
+    if (currentState == cwState)
+        encoderIncrement();
+    else if (currentState == ccwState)
+        encoderDecrement();
+    state = currentState;
+}
+
+void encoderIncrement()
+{
+    generatorPeriod += delta;
+}
+
+void encoderDecrement()
+{
+    generatorPeriod -= delta;
+}
\ No newline at end of file