This is just a simple robot arm made out of readily available materials and instruments, such as micro servos, cardboard, and hot glue. With this technology we want to show that with readily available products and materials we can make a working prototype of automated technology. With 2 buttons the movements of the robot can be saved and repeated in a loop. The project is just a start for more understanding and knowledge about Arduino. So if you want to add more movements or servo motors it can easily be done.

Step 1: Getting the Right Instruments

The robot arm is controlled with an Arduino Uno, breadboard and a list of components which are shown in the list below.

- knife - hot glue gun

- Arduino - Breadboard

- 3x servos

- 5x 221 Ohm resistance

- 2x 10K Ohm resistance

- 5x led

- 2x push button

- 3x potentiometer

- Jumpwires

Step 2: Lay-out Cardboard Parts

The servo motors are not the strongest motors that are available, so we use cardboard to make the robot arms, because it’s a light and cheap material. So draw out the parts and cut them out.

Step 3: Build the Arm

- placing the servo for the base Cut out some brackets out of the cardboard to keep the servo in its place on the baseboard.

- cut out the other arms Use the other pieces of the cardboard to cut out the arms for the other 2 servo motors. And place the motors in it.

- Assemble the 3 servos to create the motor arm. In this project we used only 3 servo motors, but it can be improved by adding more servos.

Step 4: Build the Breadboard

In order to control the robot arm we just made we need to hook up the arduino system. Here we show you the schematics for the breadboard, included with the list of materials needed.

Step 5: Programming

The arduino code that we provide you with is for controlling 3 servos and program 5 movements. The code is build in a way you can add more servos and also more movements.

code:

Servo servo1; //Servos Servo servo2; Servo servo3;

const int LED1 = 2; //LEDs const int LED2 = 3; const int LED3 = 4; const int LED4 = 7; const int LED5 = 8;

const int button1 = 12; //Buttons const int button2 = 13;

int button1Presses = 0; //Button values boolean button2Pressed = false;

const int pot1 = A0; //Potentimeters const int pot2 = A1; const int pot3 = A2;

int pot1Val; //Potentimeter values int pot2Val; int pot3Val; int pot1Angle; int pot2Angle; int pot3Angle;

int servo1PosSaves[] = {1,1,1,1,1}; //position saves int servo2PosSaves[] = {1,1,1,1,1}; int servo3PosSaves[] = {1,1,1,1,1};

void setup() { servo1.attach(5); // Set up everything and will run once; attach servos and define the pin modes servo2.attach(6); servo3.attach(9); pinMode(LED1, OUTPUT); pinMode(LED2, OUTPUT); pinMode(LED3, OUTPUT); pinMode(LED4, OUTPUT); pinMode(LED5, OUTPUT); pinMode(button1, INPUT); pinMode(button2, INPUT);

Serial.begin(9600); }

void loop() { // put your main code here, to run repeatedly: pot1Val = analogRead(pot1); // This will read the values from the potentimeters and store it... pot1Angle = map(pot1Val, 0, 1023, 0, 179); // ... and this will map the values from the potentiometers to values the servos can use and store it for later use pot2Val = analogRead(pot2); pot2Angle = map(pot2Val, 0, 1023, 0, 179); pot3Val = analogRead(pot3); pot3Angle = map(pot3Val, 0, 1023, 0, 179); servo1.write(pot1Angle); // These will make the servos move to the mapped angles servo2.write(pot2Angle); servo3.write(pot3Angle); if(digitalRead(button1) == HIGH){ // This will check how many times button1 is pressed and save the positions to an array depending on how many times it is pressed; switch/case works like a if statement button1Presses++; switch(button1Presses){ case 1: servo1PosSaves[0] = pot1Angle; servo2PosSaves[0] = pot2Angle; servo3PosSaves[0] = pot3Angle; digitalWrite(LED1, HIGH); Serial.println("Pos 1 Saved"); break; case 2: servo1PosSaves[1] = pot1Angle; servo2PosSaves[1] = pot2Angle; servo3PosSaves[1] = pot3Angle; digitalWrite(LED2, HIGH); Serial.println("Pos 2 Saved"); break; case 3: servo1PosSaves[2] = pot1Angle; servo2PosSaves[2] = pot2Angle; servo3PosSaves[2] = pot3Angle; digitalWrite(LED3, HIGH); Serial.println("Pos 3 Saved"); break; case 4: servo1PosSaves[3] = pot1Angle; servo2PosSaves[3] = pot2Angle; servo3PosSaves[3] = pot3Angle; digitalWrite(LED4, HIGH); Serial.println("Pos 4 Saved"); break; case 5: servo1PosSaves[4] = pot1Angle; servo2PosSaves[4] = pot2Angle; servo3PosSaves[4] = pot3Angle; digitalWrite(LED5, HIGH); Serial.println("Pos 5 Saved"); break; } }

if(digitalRead(button2) == HIGH){ // Pretty self-explnatory here button2Pressed = true; } if(button2Pressed){ // if the boolean button2Press is true, then the servos will run though all their saved positions for(int i = 0; i < 5; i++){ servo1.write(servo1PosSaves[i]); servo2.write(servo2PosSaves[i]); servo3.write(servo3PosSaves[i]); Serial.println(" potentimeter Angles: "); Serial.println(servo1PosSaves[i]); Serial.println(servo2PosSaves[i]); Serial.println(servo3PosSaves[i]); delay(1050); } } delay(300); }

servo_arm_code.ino
Download

Step 6: Installing the Movements

The left button is for saving a movement, the right one is to start the process after adding all the movements. With the 3 different potentiometers you can control the 3 servo motors, by turning the potentiometers the servo to which it’s connected will move. Save your movements and you have a working robot arm.