Diff: main.cpp

Revision:

8:15c6cb82c725

Parent:

7:37b06688b449

Child:

9:e09d81850a05

--- a/main.cpp	Tue Sep 30 20:30:35 2014 +0000
+++ b/main.cpp	Wed Oct 01 09:01:15 2014 +0000
@@ -3,18 +3,19 @@
 #include "HIDScope.h"
 
 #define TSAMP 0.01
-#define K_P (2     *TSAMP)
-#define K_I (0.00   *TSAMP)
+#define K_P (3     *TSAMP)
+#define K_I (0.02   *TSAMP)
 #define K_D (0      *TSAMP)
+#define I_LIMIT 1.
 
 #define POT_AVG 50
 
-void coerce(float * in, float min, float max);
+void clamp(float * in, float min, float max);
 float pid(float setpoint, float measurement);
 AnalogIn potmeter(PTC2);
 volatile bool looptimerflag;
 float potsamples[POT_AVG];
-HIDScope scope(5);
+HIDScope scope(6);
 
 
 void setlooptimerflag(void)
@@ -22,58 +23,34 @@
     looptimerflag = true;
 }
 
-/*
-void potAverager(void)
-{
-    static uint16_t sample_index = 0;
-    float voltage = potmeter.read()-.5;
 
-    potsamples[sample_index] = voltage;
-
-    sample_index++;
-    if(sample_index >= POT_AVG)
-        sample_index = 0;
-}
-
-float getpotAverage(void)
-{
-    uint16_t valuecounter;
-    float sum = 0;
-    for(valuecounter = 0 ; valuecounter < POT_AVG ; valuecounter++)
-     {
-         sum += potsamples[valuecounter];
-     }
-    return sum / (POT_AVG*1.);
-}
-*/
 
 int main()
 {
     //start Encoder
     Encoder motor1(PTD0,PTC9);
-    //Ticker to average potmeter values
-  //  Ticker potaverage;
     /*PwmOut to motor driver*/
     PwmOut pwm_motor(PTA5);
     //10kHz PWM frequency
     pwm_motor.period_us(100);
     DigitalOut motordir(PTD1);
-//    potaverage.attach(potAverager,0.002);
     Ticker looptimer;
     looptimer.attach(setlooptimerflag,TSAMP);
     while(1) {
         float setpoint;
         float new_pwm;
+        /*wait until timer has elapsed*/
         while(!looptimerflag);
-        looptimerflag = false;
-        setpoint = (potmeter.read()-.5)*2000;
-        //new_pwm = (setpoint - motor1.getPosition())*.001;
+        looptimerflag = false; //clear flag
+        /*potmeter value: 0-1*/
+        setpoint = (potmeter.read()-.5)*500;        
+        /*new_pwm = (setpoint - motor1.getPosition())*.001; -> P action*/
         new_pwm = pid(setpoint, motor1.getPosition());
-        coerce(&new_pwm, -1,1);
-        scope.set(4,motor1.getPosition());
+        clamp(&new_pwm, -1,1);
         scope.set(0, setpoint);
-        scope.set(1,new_pwm);
-        // ch 2 and 3 set in pid controller */
+        scope.set(4, new_pwm);
+        scope.set(5, motor1.getPosition());
+        // ch 1, 2 and 3 set in pid controller */
         scope.send();
         if(new_pwm > 0)
             motordir = 0;
@@ -84,10 +61,10 @@
 }
 
 
-//coerces value 'in' to min or max when exceeding those values
+//clamps value 'in' to min or max when exceeding those values
 //if you'd like to understand the statement below take a google for
 //'ternary operators'.
-void coerce(float * in, float min, float max)
+void clamp(float * in, float min, float max)
 {
     *in > min ? *in < max? : *in = max: *in = min;
 }
@@ -104,10 +81,11 @@
     out_p  = error*K_P;
     out_i += error*K_I;
     out_d  = (error-prev_error)*K_D;
-    coerce(&out_i,-0.5,0.5);
+    clamp(&out_i,-I_LIMIT,I_LIMIT);
     prev_error = error;
-    scope.set(2,error);
-    scope.set(3,out_p);
+    scope.set(1,out_p);
+    scope.set(2,out_i);
+    scope.set(3,out_d);
     return out_p + out_i + out_d;
 }