Using Joysticks and Arduino Analog Pins to Control Robot Servo Motors

Joysticks combine two variable resistors called potentiometers. We can use the Arduino's analog input pins to read each potentiometers position and then use this information to control the rotational position of a servo motor. The Arduino's analog input pins measure voltage values of 0 to 5 volts. We can connect the joysticks potentiometers to create a circuit called a voltage divider. Connecting ground (0 volts) to one side and +5 volts to the other side will allow the potentiometers center wiper pin to output a voltage of 0 to 5 volts depending on the joysticks knob position.

First lets wire up two joysticks (total of four potentiometers) to our micro-controller. The images below use a Robotio control board and the included wires and cables that are part of the Armuno Protio Falcon Robotic Arm kit. You can substitute a generic Arduino Uno or Nano with your Armio, MeArm or similar robot and your own wires to get the same result.

The Arduino source sketch code needed to read the joysticks sensors and control the servo motors is listed near the bottom of this page.

Joystick Potentiometer Arduino Servo Control Generic Diagram

Joystick Potentiometer Arduino Servo Control Diagram

Controlling Your ArmUno Robotic Arm with Joysticks

Follow the illustrated steps below to set up your robot arm to allow control with a couple of joysticks. we use the Armuno Base, Protio Joypad and the Robotio Nano Controller Board in this example but you can substitute generic parts and get the same result.

Robotio Arduino Joystick Servo Motor Robot Control Tutorial, Step 1

Step 2: Connect wires and cables to the joystick modules.

Robotio Arduino Joystick Servo Motor Robot Control Tutorial, Step 2

Step 3: Connect joystick-2 Y pin to analog pin A0.

Robotio Arduino Joystick Servo Motor Robot Control Tutorial, Step 3

Step 4: Connect joystick-1 Y pin to analog pin A1.

Robotio Arduino Joystick Servo Motor Robot Control Tutorial, Step 4

Step 5: Connect joystick-2 X, Gnd and +5v pins to analog pin A2.

Robotio Arduino Joystick Servo Motor Robot Control Tutorial, Step 5

Step 6: Connect joystick-1 X, Gnd and +5v pins to analog pin A3.

Robotio Arduino Joystick Servo Motor Robot Control Tutorial, Step 6

Step 7: Your joystick connections are complete!

Robotio Arduino Joystick Servo Motor Robot Control Tutorial, Step 7

Joystick servo control Arduino sketch source code.

Read code comments and make adjustments for your setup. Copy and Paste code into Arduino IDE software to upload to your device.

//ArmUno, Armio, MeArm Robotic Arms Analog Joystick Robotic Arm Control- Ver3.0

//Use Two Joysticks to Control Four Servo Motors 

// potentiometer wipers (middle terminal) connected to analog pins

// outside leads to ground and +5V

// More Info at www.microbotlabs.com , www.arm.uno

 

#include <Servo.h>

//######### Pin Assignments ###########

//Servo Pins
int servo1Pin = 2;
int servo2Pin = 3;
int servo3Pin = 4;
int servo4Pin = 5; 

//JoyStick Pins
int joy1XPin = A0;
int joy1YPin = A1;
int joy2XPin = A2;
int joy2YPin = A3; 

//Servo Names
Servo servo1 ;
Servo servo2 ;
Servo servo3 ;
Servo servo4 ; 

// Joystick Center deadband range, must be higher and lower than Joystick Zeroed Values
int centerDeadbandHigh = 650;
int centerDeadbandLow = 350;

//Servo update delay, lower value = faster servo movement
int servoUpdateDelay = 10; 

//Set to true to Enable Serial Out of Joystick Analog Values for Debuging
bool debugPrint = false; 

void setup(){ 

//setup serial port
  Serial.begin(9600);
  Serial.println("Analog Joy Stick Arm Control");// debug message

//assign signal pins to servos
  servo1.attach( servo1Pin);
  servo2.attach( servo2Pin );
  servo3.attach( servo3Pin);
  servo4.attach( servo4Pin );

 //
  servo1.write(90);
  servo2.write(90);
  servo3.write(90);
  servo4.write(90); 

}

void loop(){

  //joySetServoPos(1,s1,3,2,s2,2);// Joystick1: Format = Joystick X Pot(analog pin, servo, servo ID),Joystick Y Pot(analog pin, servo, servo ID)

  //
  joySetServoPos(joy1XPin,servo1,1,joy1YPin,servo2,2);
  joySetServoPos(joy2XPin,servo3,3,joy2YPin,servo4,4); 

} 

// CUSTOM FUNCTIONS 

void joySetServoPos(int joyXPin, Servo servoX, int servoXID, int joyYPin, Servo servoY, int servoYID){
 int xVal = analogRead(joyXPin);
 int yVal = analogRead(joyYPin); 

 // debug joy pot values
    if (debugPrint == true){
        Serial.print("Joy X Value= ");
     Serial.println(xVal);
     Serial.print("Joy Y Value= ");
     Serial.println(yVal);

    } 

 //Skip servo pos update and Delay if both joy pots are centered
 if(xVal > centerDeadbandLow && xVal < centerDeadbandHigh) {
  if(yVal > centerDeadbandLow && yVal < centerDeadbandHigh){
           // debug
           if (debugPrint == true){
     Serial.println("Joy X Zeroed");
           Serial.println("Joy Y Zeroed");
           }

     goto skipServoUpdate;

  }

 }

 //inc or dec servo position depending on joystick pot positions
 if (xVal > centerDeadbandHigh){
  servoX.write(servoX.read()+1);

  //Send servo pos and servo ID to external program
        if (debugPrint == true){
  Serial.print(servoX.read());
  Serial.print("S");
  Serial.println(servoXID);
        }

 }

 if (xVal < centerDeadbandLow){
  servoX.write(servoX.read()-1);
  //Send servo pos and servo ID to external program
        if (debugPrint == true){
  Serial.print(servoX.read());
  Serial.print("S");
  Serial.println(servoXID);

        }

 }

 if (yVal > centerDeadbandHigh){
  servoY.write(servoY.read()+1);

  //Send servo pos and servo ID to external program
        if (debugPrint == true){
  Serial.print(servoY.read());
  Serial.print("S");
  Serial.println(servoYID);

        }

 }

 if (yVal < centerDeadbandLow){
  servoY.write(servoY.read()-1);

  //Send servo pos and servo ID to external program
        if (debugPrint == true){
  Serial.print(servoY.read());
  Serial.print("S");
  Serial.println(servoYID);

        }

 } 

 delay(servoUpdateDelay);
 skipServoUpdate:;

}

Have a Question, Need Help?

Our Make & Learn Brands: MICROBOTLABS™ ARM.UNO™ ROBOTIO™ PROTIO™ ARMIO™ ANITRON™ ANITRONIC™ ARM.ONE™