main.cpp

00001 #include "mbed.h"
00002 #include "string.h" 
00003 
00004 #define REFERENCEVOLTAGE 3.3    // Max Output voltage from DAC
00005 
00006 AnalogIn y(PTB3); // Analog Input
00007 AnalogOut u(PTE30); // Analog Output
00008 Serial HC06(PTE0,PTE1);
00009 PwmOut led1(LED_RED);
00010 
00011 int Kp, Ki, Kd, Sp;
00012 float pid,o,ai,ad,ap,med,err;
00013 float err_v;
00014 char buffer[6];
00015 
00016 /* Funciones */
00017 void cleanBuffer(char *buffer, int count) { 
00018     for(int i=0; i < count; i++) {
00019         buffer[i] = '\0';
00020     }
00021 }
00022 
00023 void PID(int Sp, int Kp, int Ki, int Kd) { 
00024     
00025     med = y.read()*999; // med = Ist-Wert (medido)
00026     err = (Sp-med); // err = Soll-Wert (Sp) - Ist-Wert (med) = Fehler/Reglerabweichung
00027     ap = Kp * err * 0.01f;  // Proportional
00028     ai = (Ki * err * 0.01f) + ai;   // Integral (aktueller Fehler wird immer weiter aufsummiert)
00029     ad = Kd * (err - err_v) * 0.01f; // Differential (groesse der Fehlerabweichung (= Geschwindigkeit der Aenderung)
00030     pid = (ap + ai + ad);
00031     
00032     if(pid <= 0) {
00033         pid = 0;
00034     }
00035     if(pid > 999) {
00036         pid = 999;
00037     }  
00038     
00039     // Normalize PID-Output
00040     err_v = err;
00041     o = pid / 999;
00042     u.write(o); // Write PID-value to Analog Output
00043     
00044     if(err > -2 && err < 2) {
00045         led1 = 0.9;
00046     }
00047     else {
00048         led1 = 1;
00049     }
00050     
00051     HC06.printf("SetPoint: %d \r\n",Sp);
00052     HC06.printf("Entrada: %0.2f \r\n",med);
00053     HC06.printf("Error: %0.2f \r\n",err);
00054     HC06.printf("Salida: %0.2f \r\n",pid);
00055     HC06.printf("DAC-Output: %0.2f V \r\n",o);
00056     HC06.printf("Voltaje: %0.2f V \r\n",o*REFERENCEVOLTAGE); // Resulting voltage (0V ... 3.3V)
00057     HC06.printf("\r\n");
00058     
00059     wait_ms(500);
00060 }
00061 
00062 
00063 
00064 int main() {
00065     
00066     led1 = 1;
00067     HC06.baud(9600);
00068     
00069     int readptr = 0;
00070     char c;
00071     
00072     
00073     HC06.printf("\r\nEnter SetPoint value (Sp): ");
00074     while( (c = HC06.getc()) != '\n') { // Get characters and write them to buffer[]-Chararray
00075         buffer[readptr++] = c; 
00076     }
00077     Sp = atoi(buffer); // Convert string (= Char[]-Array) to integer
00078     readptr = 0; // Reset String-Characterindex
00079     cleanBuffer(buffer,6); // Set all string-characters to \0 that no false chars remain for next use of buffer
00080     
00081     
00082     HC06.printf("\r\nEnter Proportional-Factor value (Kp): ");
00083     while( (c = HC06.getc()) != '\n') {
00084         buffer[readptr++] = c; 
00085     }
00086     Kp = atoi(buffer);
00087     readptr = 0;
00088     cleanBuffer(buffer,6);
00089     
00090     
00091     HC06.printf("\r\nEnter Integral-Factor value (Ki): ");
00092     while( (c = HC06.getc()) != '\n') {
00093         buffer[readptr++] = c; 
00094     }
00095     Ki = atoi(buffer);
00096     readptr = 0;
00097     cleanBuffer(buffer,6);
00098     
00099     
00100     HC06.printf("\r\nEnter Differential-Factor value (Kd): ");
00101     while( (c = HC06.getc()) != '\n') {
00102         buffer[readptr++] = c; 
00103     }
00104     Kd = atoi(buffer);
00105     readptr = 0;
00106     cleanBuffer(buffer,6);
00107     
00108     HC06.printf("\r\nStarting PID-controlling to Sp = %d with Kp = %d / Ki = %d / Kd = %d\r\n", Sp, Kp, Ki, Kd);
00109     
00110     while(1){
00111         if (HC06.readable()) { // Wait for any key sent to get new Sp value
00112             HC06.getc(); // Erase first key from buffer (dummy signal-key typed to indicate the following new Sp-input)
00113             
00114             HC06.printf("\r\n\r\n\r\nEnter a new SetPoint value (Sp): ");
00115             while( (c = HC06.getc()) != '\n') {
00116                 buffer[readptr++] = c;
00117             }
00118             Sp = atoi(buffer);
00119             readptr = 0;
00120             cleanBuffer(buffer,6);
00121             
00122             HC06.printf("\r\nSuccessfully changed Setpoint-Value to Sp = %d (= %0.2f V)\r\n\r\n", Sp, (Sp*REFERENCEVOLTAGE/999));
00123         }
00124         
00125         PID(Sp, Kp, Ki, Kd);
00126     }
00127 }