Mastering Arduino PID Controller A Complete Hands-On Tutorial

You can make and adjust an Arduino PID Controller with easy steps and simple tools. Many robots use PID control to move exactly, like when they travel in warehouses or join First Robotics Competitions.

• Some common uses are robot balancing and moving with sensors like the MPU6050.

Beginners often face problems, such as:

1. Making sure the sample time stays the same for smooth work.

2. Stopping quick changes when starting up.

3. Changing tuning settings without turning off the controller.

Get an Arduino board, sensors, and simple wires to begin.

Key Takeaways

• Learn the basics of PID control. It helps machines work better by reducing mistakes and keeping a target value.

• Use Arduino for PID control because it is easy to use and does not need much hardware. This makes it good for people who are just starting.

• Follow simple wiring steps to connect parts the right way. Good connections make sure your PID controller works like it should.

• Change the Kp, Ki, and Kd values to tune your PID controller. Doing this helps your system work better and stay steady.

• Test and fix your setup often. Checking it often helps you find problems early and keeps your control system working well.

Arduino PID Controller Basics

What Is PID Control

A PID controller helps machines work better and smoother. It checks what the system is doing all the time. The controller wants the system to reach a goal called the setpoint. If the system is not at the setpoint, there is an error. The controller changes things to make the error smaller. PID stands for Proportional, Integral, and Derivative. Each part does something special:

• The proportional part fixes the error fast.

• The integral part looks at old errors and helps fix them.

• The derivative part guesses what will happen and stops quick changes.

This way, feedback systems can stay steady and work well.

Why Use PID on Arduino

An Arduino PID controller helps you make a good control system. Arduino is simple to use for PID and does not need much hardware. You can change the controller settings fast and see good results. Here is a table that shows the main good points:

Advantage	Description
Greater Accuracy	You get better results than with on/off controllers.
Energy Efficiency	The system uses less energy.
Low Hardware Requirements	You only need simple parts, so it is cheaper.
Ease of Tuning	You can change the settings easily.
Versatility	You can use PID in many different systems.
Process Longevity	Your devices last longer because control is smoother.
Response to Disturbances	The controller reacts fast to changes.
Established Use	PID has worked well for a long time in many projects.

PID Applications

You can use Arduino PID controllers in many real projects. For example:

• You can control how fast motors spin in robots.

• You can keep a robot arm still.

• You can check temperature, humidity, or light with sensors.

• You can use pumps, lights, or heaters to react when needed.

• You can make a robot that balances by changing motor speed.

• You can build a robot that follows a line using sensors.

These examples show how PID helps you make smart and steady systems.

Components and Wiring Setup

Hardware List

You need a few basic parts to build your arduino pid controller. Here is a simple list to help you get started:

Component	Purpose
Arduino Uno	Main controller board
LED	Shows output or status
Button	Lets you set or reset values
Temperature Sensor	Measures system temperature
Hall Effect Sensor	Detects speed or position
Actuator (Motor)	Moves or changes something
Jumper Wires	Connects all parts together
Breadboard	Holds components for testing
Power Supply	Powers the whole system

You can add other sensors or actuators if you want to control different things.

Wiring Arduino for PID

You must connect each part in the right way for your pid project to work. Follow these steps:

1. Place the Arduino Uno on your workspace.

2. Connect the temperature sensor to the analog input pin (for example, A0).

3. Wire the hall effect sensor:

   • Red wire to 5V

   • Black wire to GND

   • Yellow wire to an interrupt pin (like pin 2)

4. Attach the actuator (motor):

   • Red wire to MOTA on the motor shield

   • Black wire to MOTB on the motor shield

5. Connect the LED to a digital output pin (such as pin 13) with a resistor.

6. Wire two buttons between pins 4 and 7, and connect them to GND.

7. Use jumper wires to link all parts on the breadboard.

8. Connect the power supply:

   • 12V to BAT+

   • GND to BAT-

   • 12V to Vin on the Arduino

Tip: Always connect the circuit from input to output. The sensor sends data to the Arduino. The Arduino uses the pid algorithm to control the actuator.

Common Setup Issues

You may face some problems when wiring your arduino pid controller. Here are a few common issues and how to fix them:

• Loose wires can cause sensors or actuators to stop working. Check all connections.

• Wrong pin numbers may lead to errors. Double-check your code and wiring.

• Power supply problems can make the system unstable. Use the correct voltage.

• If the LED does not light up, check the resistor and pin assignment.

• Sensors may not read values if placed too far from the Arduino.

Note: Test each part before running the full control system. This helps you find problems early.

PID Algorithm Explained

Proportional, Integral, Derivative

You can understand the pid algorithm by looking at its three main parts: proportional, integral, and derivative. Each part helps you control your system in a different way. Here is a table that shows how each term works to fix errors:

Term	Contribution to Error Correction
Proportional	Adjusts output based on current error. Larger errors lead to bigger corrections.
Integral	Changes output based on the sum of past errors. This helps remove steady-state error.
Derivative	Adjusts output based on how fast the error is changing. This helps stop sudden changes and keeps the system stable.

You use these three terms together to make your system respond quickly, stay steady, and avoid overshooting the target.

PID Formula Overview

The pid algorithm uses a simple formula to calculate the correction value. You can see the formula below:

Correction = Kp × Error + Ki × Sum of Errors + Kd × Change in Error

• Kp is the proportional gain. It decides how much you react to the current error.

• Ki is the integral gain. It decides how much you react to the total error over time.

• Kd is the derivative gain. It decides how much you react to the speed of error change.

In Arduino code, you often use a loop to update these values. You read the sensor, find the error, and use the formula to set the output. This output controls things like motors or heaters.

How PID Minimizes Error

The pid algorithm works hard to keep your system close to the setpoint. The integral part is very important for removing steady-state error. It adds up all past errors. Even small errors will build up and push the output to fix them. If your system keeps missing the target, the integral term grows and helps drive the error to zero.

The derivative part helps you avoid quick jumps and keeps the system smooth. The proportional part gives you fast corrections. When you use all three together, you get a system that reacts quickly, stays steady, and does not overshoot.

Tip: You can tune the Kp, Ki, and Kd values to get the best performance for your project.

Coding and Implementation

Arduino Sketch Setup

Before you start coding, you need to set up your Arduino sketch. First, gather all your parts. You need an Arduino board, sensors, actuators, a breadboard, jumper wires, and a power supply. Make sure the Arduino IDE is on your computer. Next, install the PID library. Open the Arduino IDE. Go to Sketch, then Include Library, then Manage Libraries. Search for "PID" and click install. Learn how PID control works. The proportional, integral, and derivative terms work together. Build your circuit. Connect the sensors and actuators to the Arduino board. Follow your schematic. Write your PID control code. Set up variables and configure the PID library. Make the main loop. Tune your PID controller. Change the Kp, Ki, and Kd values for better results. Test and debug your code. Upload it and watch how your system works. Make changes if you need to.

Tip: Always check your wiring before you upload code. This helps stop errors and keeps your hardware safe.

Writing the PID Algorithm

You can write your own PID algorithm in Arduino code. This lets you control every part of the process. Here are some good tips: Stop integral windup. Do not add error when the output is at its max or min. This keeps your system from going too far. Use feedforward control. Add a term that reacts fast to setpoint changes. This helps your system respond quickly. Model your system. Use extra sensors, like temperature sensors, to learn how your system works. This makes your PID controller more accurate.

Here is a simple example of a manual PID algorithm in Arduino code:

float setpoint = 100; // Target value
float input = 0;      // Sensor reading
float output = 0;     // Output to actuator

float Kp = 2.0;
float Ki = 0.5;
float Kd = 1.0;

float error = 0;
float previous_error = 0;
float integral = 0;
float derivative = 0;

void loop() {
  input = analogRead(A0); // Read sensor
  error = setpoint - input;
  integral += error;
  derivative = error - previous_error;

  output = Kp * error + Ki * integral + Kd * derivative;

  // Prevent integral windup
  if (output > 255) {
    output = 255;
    integral -= error;
  }
  if (output < 0) {
    output = 0;
    integral -= error;
  }

  analogWrite(9, output); // Send output to actuator
  previous_error = error;
  delay(10);
}

Note: You can change the Kp, Ki, and Kd values to tune your controller. Start with Kp. Then change Ki and Kd for better results.

Using the PID Library

The Arduino PID library makes PID control easier to use. You do not need to know all the math. The library does the hard work. You can focus on tuning and testing. The library gives you a simple way to do PID calculations. You can set different setpoints for each motor or actuator. The library has advanced features like anti-windup. You can control many motors, each with its own PID controller.

Here is a basic example using the PID library:

#include <PID_v1.h>

double setpoint, input, output;
double Kp = 2, Ki = 0.5, Kd = 1;

PID myPID(&input, &output, &setpoint, Kp, Ki, Kd, DIRECT);

void setup() {
  input = analogRead(A0);
  setpoint = 100;
  myPID.SetMode(AUTOMATIC);
}

void loop() {
  input = analogRead(A0);
  myPID.Compute();
  analogWrite(9, output);
  delay(10);
}

Feature	Manual PID Coding	Arduino PID Library
Ease of Use	Needs a lot of learning	Easy with built-in functions
Implementation Details	You must write your own code	Has ready-to-use functions
Additional Features	Only basic PID features	Has tuning and debugging tools

Tip: The PID library helps you avoid mistakes and saves time. You can spend more time testing and tuning your system.

Controlling Actuators

You use the PID controller output to control things like motors or LEDs. Here is how you do it: Connect a feedback device, like a linear potentiometer, to the Arduino's analog input. This gives your PID controller the data it needs. Tune your PID constants. Start with Kp. Raise it until the system starts to move back and forth. Then change Kd and Ki to make the system stable and accurate. Test your setup. Use tools like the X-Sim plugin to set output values. Watch how your motor or LED reacts.

You can control many types of actuators with your Arduino PID controller. For example, use analogWrite to set a motor's speed or an LED's brightness. The PID output changes the actuator to keep your system close to the setpoint.

Note: Always test your actuator with small values first. This helps you avoid damage and makes tuning easier.

PID Tuning and Testing

Manual Tuning Tips

You can tune your arduino pid controller by adjusting three main values: Kp, Ki, and Kd. These values help your control algorithm work better. Manual tuning gives you a simple way to find the best settings for your project. Follow these steps to tune your controller:

1. Set Kp, Ki, and Kd to zero. This gives you a clean starting point.

2. Slowly increase Kp. Watch how your system reacts. When you see the system start to move toward the setpoint, keep increasing Kp until you notice steady oscillation or the error becomes very small.

3. Add a little Ki. This value helps remove any steady-state error. Increase Ki until the error disappears, but stop if the system starts to oscillate too much.

4. Raise Kd in small steps. Kd helps stop quick changes and smooths out the response. Increase Kd until the system stops oscillating and becomes stable.

Tip: Make small changes to each value. Watch how your system responds after each adjustment.

You can also use another method. Start with all values at zero. Increase Kp until the system starts to oscillate around the setpoint. Write down the gain where this happens. This is your critical gain. You can use this value to help calculate other settings if you want to try more advanced tuning.

Testing Your Controller

Testing your controller helps you see if your pid algorithm works as you expect. You can use a simple step-by-step process to check your setup:

1. Start your system in an unknown state. For example, block a light barrier with a photoresistor.

2. Wait for the sensor to detect a change, like a hole appearing in a spinning disk. Save the time when this happens.

3. Watch for the sensor to show the hole disappears.

4. Wait for the next hole to appear and record the time again.

This process helps you measure how well your controller responds to changes. You can use the data to adjust your algorithm and improve control. Try different setpoints and see how fast and accurately your system reaches the target.

Note: Always test your controller at a safe speed. Start at 50% power. This makes it easier to spot problems and keeps your hardware safe.

Troubleshooting

You may face some common problems when tuning or testing your arduino pid controller. Here are some tips to help you fix them:

• Check your power supply. Make sure it is reliable and gives the right voltage.

• Inspect all wiring. Look for loose connections or damaged wires.

• Test your sensors. Make sure they give accurate readings.

• Start tuning at half speed. Full speed can make tuning harder and cause errors.

• If your system does not follow the setpoint, check the position of your sensors. Sometimes you need a higher Kp if the sensor is far from the actuator.

• If your system reacts slowly, your processor may be too slow. Try increasing the sample rate or using a faster arduino.

• If you see ringing or oscillation, lower Kp or increase Kd.

• If the error never goes away, try increasing Ki a little at a time.

• Use your controller’s diagnostic tools if you have them. Check for error codes or messages.

• Calibrate your sensors and actuators often. This keeps your system working well.

Tip: If you cannot solve a problem, ask for help from the Arduino community or check the manual for your hardware.

You can keep your control system running smoothly by following these steps. Regular checks and small changes help you get the best results from your pid algorithm.

You now know how to make and adjust an Arduino PID controller. First, you need to learn how your system works by using manual mode. Next, change the PID settings and see what happens. Try different ways to tune your controller.

• Tuning does not stop after one try.

• Each PID value makes your system act in a new way.

You can get better at this by doing these things:

Step	Description
1	Use the PID library to start your project.
2	Set output limits and pick modes for more control.
3	Add real sensors to get feedback for closed-loop systems.
4	Test the PID Tuning Example to watch what changes.
5	Try PID_AutoTune to tune your controller by itself.

Learning about PID controllers helps you do more in robotics and automation. Working with Arduino is fun and you learn a lot. 🚀

 

 

 

 

 

Written by Jack Elliott from AIChipLink.

 

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