Diff: main.cpp

Revision:

0:8f8157690923

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Mon Oct 10 10:06:57 2016 +0000
@@ -0,0 +1,73 @@
+#include "mbed.h"
+#include <math.h>
+#include "MODSERIAL.h"
+
+AnalogIn potMeterIn(A0);
+DigitalIn button1(D7);
+DigitalOut motor1DirectionPin(D4);
+PwmOut motor1MagnitudePin(D5);
+
+Serial pc(USBTX,USBRX);
+Ticker MeasureTicker;
+
+volatile float referenceVelocity = 0;  // in rad/s
+
+float GetReferenceVelocity()
+{
+    // Returns reference velocity in rad/s. 
+    // Positive value means clockwise rotation.
+    const float maxVelocity=8.4; // in rad/s of course!
+    
+    if (button1)
+    {
+        // Clockwise rotation
+        referenceVelocity = potMeterIn * maxVelocity;
+    } else
+    {
+        // Counterclockwise rotation
+        referenceVelocity = -1*potMeterIn * maxVelocity;
+    }
+    return referenceVelocity;
+}
+
+float FeedForwardControl(float referenceVelocity)
+{
+    // very simple linear feed-forward control
+    const float MotorGain=8.4; // unit: (rad/s) / PWM
+    volatile float motorValue = referenceVelocity / MotorGain;
+    return motorValue;
+}
+
+void SetMotor1(float motorValue)
+{
+    // Given -1<=motorValue<=1, this sets the PWM and direction
+    // bits for motor 1. Positive value makes motor rotating
+    // clockwise. motorValues outside range are truncated to
+    // within range
+    if (motorValue >=0) motor1DirectionPin=1;
+        else motor1DirectionPin=0;
+    if (fabs(motorValue)>1) motor1MagnitudePin = 1;
+        else motor1MagnitudePin = fabs(motorValue);
+}
+
+void MeasureAndControl(void)
+{
+    // This function measures the potmeter position, extracts a
+    // reference velocity from it, and controls the motor with 
+    // a simple FeedForward controller. Call this from a Ticker.
+    volatile float referenceVelocity = GetReferenceVelocity();
+    float motorValue = FeedForwardControl(referenceVelocity);
+    SetMotor1(motorValue);
+}
+
+
+int main()
+{
+ 
+ //Initialize
+ MeasureTicker.attach(&MeasureAndControl, 1.0/100); 
+ pc.printf("Reference velocity: %f rad/s \r\n", referenceVelocity);
+ pc.baud(115200);  
+ while(true)
+ {}
+}
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