Revision 0:6f586d7c134c, committed 2012-10-11

Comitter:

lhiggs

Date:

Thu Oct 11 23:10:44 2012 +0000

Commit message:

First version of motor control example using an opto interrupter and H-Bridge.

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu Oct 11 23:10:44 2012 +0000
@@ -0,0 +1,76 @@
+#include "mbed.h"
+
+PwmOut EN(p22);
+DigitalOut A1(p16);
+DigitalOut A2(p17);
+
+Serial pc(USBTX, USBRX);
+
+long float delta_time = 0;
+float rpm = 0;
+float inc_enc_constant = 0.03125;    // 32 Encoder Ticks per Revolution
+
+
+Timer t;
+// t.read_us() is 32bit interger, max 2^31 - 1 = 2147483647 us = 2147.483647 s = 35.7913941167 min
+
+class Counter
+{
+public:
+
+
+    Counter(PinName pin) : _interrupt(pin) {        // create the InterruptIn on the pin specified to Counter
+        _interrupt.fall(this, &Counter::increment); // attach increment function of this counter instance
+    }
+
+
+    void increment() {
+        delta_time = t.read_us();
+        t.reset();
+
+        rpm = ( inc_enc_constant  / (delta_time/1000000) ) *60 ; // rev / m
+
+        _count++;
+    }
+
+    int read() {
+        return _count;
+    }
+
+private:
+    InterruptIn _interrupt;
+    volatile int _count;
+};
+
+
+
+
+
+Counter counter(p30);   // opto interrupter counter
+
+int main()
+{
+    pc.baud(115200);
+    EN.period(0.020);
+
+    t.start();
+
+    float duty = 0.10;
+
+    while(1) {
+
+        wait(1);
+
+        EN.write(duty);
+        duty = duty + 0.01; // increment H-Bridge EN PWM duty cycle 1%
+        A1 = 1;         // set H-Bridge input A1 high
+        A2 = 0;         // set H-Bridge input A2 low
+
+        // pc.printf("Count so far: %d\n", counter.read());
+        // pc.printf("dt: %d\n", delta_time);
+
+        pc.printf("RPM: %f\n", rpm);
+        pc.printf("DUTY CYCLE: %f\n",duty);
+
+    }
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Thu Oct 11 23:10:44 2012 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/cd19af002ccc
\ No newline at end of file