Nikita Klimchuk
/
blog_PID_simpler
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Revision 0:febde40ccef5, committed 2020-12-14
- Comitter:
- nikitakl
- Date:
- Mon Dec 14 14:23:04 2020 +0000
- Commit message:
- Simpler version of PID based on the blog; http://brettbeauregard.com/blog/2011/04/improving-the-beginners-pid-introduction/
Changed in this revision
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/PID.lib Mon Dec 14 14:23:04 2020 +0000 @@ -0,0 +1,1 @@ +https://os.mbed.com/users/aberk/code/PID/#6e12a3e5af19
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/PID_simpler.cpp Mon Dec 14 14:23:04 2020 +0000
@@ -0,0 +1,76 @@
+#include "mbed.h"
+#include "millis.h"
+/*working variables*/
+
+#define threshold 0.003 // 1/330
+
+AnalogIn temperature(p20);
+PwmOut fanControl(p21);
+//static BufferedSerial pc(USBTX, USBRX);
+
+Ticker temperatureTicker;
+
+int readTemperatureFlag=0;
+unsigned long lastTime;
+double Input, Output, Setpoint;
+double errSum, lastErr;
+double kp, ki, kd;
+void Compute()
+{
+ /*How long since we last calculated*/
+ unsigned long now = millis();
+ double timeChange = (double)(now - lastTime);
+
+ /*Compute all the working error variables*/
+ double error = Setpoint - Input;
+ errSum += (error * timeChange);
+ double dErr = (error - lastErr) / timeChange;
+
+ /*Compute PID Output*/
+ Output = kp * error + ki * errSum + kd * dErr;
+
+ /*Remember some variables for next time*/
+ lastErr = error;
+ lastTime = now;
+}
+
+void SetTunings(double Kp, double Ki, double Kd)
+{
+ kp = Kp;
+ ki = Ki;
+ kd = Kd;
+}
+void tickerFlagOn()
+{
+ //led2 = !led2;
+ readTemperatureFlag=1;
+}
+
+int main()
+{
+ float oldTemperature = temperature.read();
+ float newTemperature= oldTemperature;
+ temperatureTicker.attach(&tickerFlagOn, 0.200); // the address of the function to be attached (tickerFlagOn) and the interval (0.2 seconds)
+
+ while (1)
+ {
+ if (readTemperatureFlag)
+ {
+ readTemperatureFlag=0;
+ newTemperature = temperature.read();
+ if ((newTemperature < (oldTemperature-threshold)) || (newTemperature > (oldTemperature+threshold)))
+ {
+ oldTemperature = newTemperature; // These are for the threshold
+ printf("AnalogIn=%f, Temperature= %.1f degrees\n\r", oldTemperature, 3.3*oldTemperature*100);
+ }
+ }
+
+ Input=oldTemperature;
+ Setpoint= 0.0757575757575758;
+ SetTunings(1, 0, 0);
+ Compute();
+ fanControl.write(Output);
+ printf("fanSpeed=%f \n \r", Output);
+ wait(1);
+ }
+}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Mon Dec 14 14:23:04 2020 +0000 @@ -0,0 +1,1 @@ +https://os.mbed.com/users/mbed_official/code/mbed/builds/65be27845400 \ No newline at end of file
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/millis.lib Mon Dec 14 14:23:04 2020 +0000 @@ -0,0 +1,1 @@ +https://os.mbed.com/users/hudakz/code/millis/#ac7586424119