Gerhard Berman
Simple program to control pololu motor with button (direction) and potmeter (velocity)
Revision 0:8f8157690923, committed 2016-10-10
- Comitter:
- GerhardBerman
- Date:
- Mon Oct 10 10:06:57 2016 +0000
- Commit message:
- motor working, potmeter not working;
Changed in this revision
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/MODSERIAL.lib Mon Oct 10 10:06:57 2016 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/Sissors/code/MODSERIAL/#4737f8a5b018
--- /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)
+ {}
+}
\ No newline at end of file
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Mon Oct 10 10:06:57 2016 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_official/code/mbed/builds/25aea2a3f4e3 \ No newline at end of file