Arduino PID Controller

A lightweight Arduino-compatible PID controller with additional features for smooth and stable control of slow or overshoot-prone processes.

Features

• Proportional, integral and derivative control
• Derivative-on-measurement
• Derivative low-pass filtering
• Integral activation range
• Setpoint tolerance output hold
• Conditional integration / anti-windup
• Direct and reverse controller direction
• Configurable output limits
• Output slew-rate limiting
• Rollover-safe millis() timing
• Independent operation of multiple PID instances

Basic Usage

#include "pidController.hpp"

PID pid;

void setup()
{
    pid.setDirection(PID::Direction::DIRECT);

    pid.setLimits(0.0, 1023.0);
    pid.setSampletime(100);

    pid.setTolerance(2);
    pid.setIntegralActivationRange(10.0);

    pid.setDerivativeFilter(0.5);
    pid.setOutputSlewRate(150.0);

    pid.setTunings(
        5.0,    // Kp
        0.3,    // Ki
        2.0);   // Kd
}

void loop()
{
    const double setpoint = 100.0;
    const double actual = readProcessValue();

    const double output =
        pid.calc(setpoint, actual);

    applyControllerOutput(output);
}

Documentation

Detailed documentation, controller concepts, API reference, tuning recommendations and implementation notes are available in the project Wiki:

Arduino PID Wiki

The Wiki repository can also be cloned directly:

git clone https://github.com/AlexanderTonn/Arduino_PID.wiki.git

Notes

PID parameters from other implementations may require retuning because this controller uses time-correct integral and derivative calculations in seconds.

For overshoot-prone systems, start with the proportional term, add derivative action for damping, and introduce only a small integral term afterwards.