[Arduino] LED PID제어

링크

PID 제어를 이용해서

LED 밝기를 제어

구글링을 해서 잘 설명된 PDF가 있네..

참고참고!

모터 PID 제어를 위하여!!

ps. 모터 PID 제어를 위해선 Feedback을 받기 위한 장치가 있어야 하는데..

인코더 달린 모터는 왜이리 비싸냐는... ㅠㅠ

그러다가 어디서 언뜻 봤는데..

옛날 볼 마우스에 인코더가 달려 있다는 말을 듣고 

얼른 볼 마우스를 구해서 보니

아앗!!

인코더가 있다!!

무려 3개씩이나!!

휠에 하나 볼마우스 X, Y축에 각각 하나씩!

다만 휠은 해상도가 좀 떨어지네 ㅎㅎ;;

#include <PID_v1.h> 

const int photores = A5;     // Photo resistor input 

const int pot = A4;          // Potentiometer input 

const int led = 9;           // LED output 

double lightLevel;           // variable that stores the incoming light level 

 

                  // Tuning parameters 

float Kp=0;       //Initial Proportional Gain 

float Ki=10;      //Initial Integral Gain 

float Kd=0;       //Initial Differential Gain 

 

double Setpoint, Input, Output; //These are just variables for storingvalues 

PID myPID(&Input, &Output, &Setpoint, Kp, Ki, Kd, DIRECT); 

             // This sets up our PDID Loop 

             //Input is our PV 

             //Output is our u(t) 

             //Setpoint is our SP 

const int sampleRate = 1;       // Variable that determines how fast our PID loop runs 

 

                                // Communication setup 

const long serialPing = 100;    //This determines how often we ping our loop 

                                // Serial pingback interval in milliseconds 

unsigned long now = 0;          //This variable is used to keep track of time 

                                // placehodler for current timestamp 

unsigned long lastMessage = 0;  //This keeps track of when our loop last spoke to serial 

                                // last message timestamp. 

 

void setup(){ 

 lightLevel = analogRead(photores);                //Read in light level 

 Input = map(lightLevel, 0, 1024, 0, 255);         //Change read scale to analog out scale 

 Setpoint = map(analogRead(pot), 0, 1024, 0, 255); 

                                                  //get our setpoint from our pot 

 Serial.begin(9600);                             //Start a serial session 

 myPID.SetMode(AUTOMATIC);                        //Turn on the PID loop 

 myPID.SetSampleTime(sampleRate);                 //Sets the sample rate 

 

 Serial.println("Begin");                        // Hello World! 

 lastMessage = millis();                          // timestamp 

} 

 

void loop(){ 

  Setpoint = map(analogRead(pot), 0, 1024, 0, 255);   //Read our setpoint  lightLevel = analogRead(photores); //Get the light level

  Input = map(lightLevel, 0, 900, 0, 255);             //Map it to the right scale

  myPID.Compute();                                     //Run the PID loop 

  analogWrite(led, Output);                             //Write out the output from the PID loop to our LED pin 

 

  now = millis();                                       //Keep track of time 

  if(now - lastMessage > serialPing) {                 //If it has been long enough give us some info on serial 

                                                     // this should execute less frequently 

                                                     // send a message back to the mother ship 

  Serial.print("Setpoint = "); 

  Serial.print(Setpoint); 

  Serial.print(" Input = "); 

  Serial.print(Input); 

  Serial.print(" Output = "); 

  Serial.print(Output); 

  Serial.print("\n"); 

  if (Serial.available() > 0) {                   //If we sent the program a command deal with it 

    for (int x = 0; x < 4; x++) { 

      switch (x) { 

        case 0: 

          Kp = Serial.parseFloat(); 

          break; 

        case 1: 

          Ki = Serial.parseFloat(); 

          break; 

        case 2: 

          Kd = Serial.parseFloat(); 

          break; 

        case 3: 

          for (int y = Serial.available(); y == 0; y--) { 

            Serial.read(); //Clear out any residual junk 

          } 

          break; 

        } 

      } 

      Serial.print(" Kp,Ki,Kd = "); 

      Serial.print(Kp); 

      Serial.print(","); 

      Serial.print(Ki); 

      Serial.print(","); 

      Serial.println(Kd); //Let us know what we just received 

      myPID.SetTunings(Kp, Ki, Kd); //Set the PID gain constants and start running 

    }   

    lastMessage = now; 

     //update the time stamp. 

  } 

}