Important changes to repositories hosted on mbed.com
Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.
To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.
It is also possible to export all your personal repositories from the account settings page.
Dependencies: Encoder HIDScope MODSERIAL mbed-dsp mbed
Fork of BMT-M9_motorcontrol by
Revision 8:15c6cb82c725, committed 2014-10-01
- Comitter:
- vsluiter
- Date:
- Wed Oct 01 09:01:15 2014 +0000
- Parent:
- 7:37b06688b449
- Child:
- 9:e09d81850a05
- Commit message:
- cleaned up code
Changed in this revision
| main.cpp | Show annotated file Show diff for this revision Revisions of this file |
--- 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;
}
