【2025 ESP32】PID控制完整教學：原理、公式與實際應用案例

				
					#include <OneWire.h>
#include <DallasTemperature.h>

#define ONE_WIRE_BUS 4
#define RELAY_PIN 5

double Setpoint = 25.0; // 目標溫度
double Input, Output;
double Kp = 2.0, Ki = 0.5, Kd = 1.0;

double errSum = 0, lastErr = 0;

OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);

void setup() {
  Serial.begin(115200);
  pinMode(RELAY_PIN, OUTPUT);
  sensors.begin();
}

void loop() {
  sensors.requestTemperatures();
  Input = sensors.getTempCByIndex(0);

  double error = Setpoint - Input;
  errSum += error;
  double dErr = error - lastErr;

  Output = Kp*error + Ki*errSum + Kd*dErr;

  // 控制繼電器（加熱器）
  if (Output > 0) {
    digitalWrite(RELAY_PIN, HIGH);
  } else {
    digitalWrite(RELAY_PIN, LOW);
  }

  lastErr = error;

  Serial.print("Temp: "); Serial.print(Input);
  Serial.print(" Output: "); Serial.println(Output);

  delay(1000);
}