Arduino Robotic Arm (3D Printed)

by Giannis Vasilakis in Circuits > Arduino

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Arduino Robotic Arm (3D Printed)

If you have a 3D printer then... you must try to build one of this robotic arm-grab toy! The robotic arm can learn what to do on every start up. Use the potentiometers (one per servo) and the "teach" button and make your arm to grab.. everything!

In this DIY guide you will find the part list, circuit connections, Arduino code and of course 3D files of this amazing toy.

~Project updates can be found here:

https://www.ardumotive.com/roboticarmgrab-en.html

~Watch the video below:

What You Will Need - Hardware

For this project you will need:

Tip: You can use any Arduino board!

The Circuit

The connections are pretty easy, see the above image with the breadboard circuit schematic.

Servo Motors:

Servo for Grab movement to Arduino pin 6
Servo for Rotate movement to Arduino pin 5
Servo for Up/Down movement to Arduino pin 4
Servo for Forward/Backward movement to Arduino pin 3

All black cables to GND
All red cables to Vcc - 5V

Potentiometers:

Grab movement to Arduino pin A0
Rotate movement to Arduino pin A1
Up/Down movement to Arduino pin A2
Forward/Backward movement to Arduino pin A3

All left pins to GND
All right pins to Vcc - 5V

Buttons:

Teach button to Arduino pin 7
Start button to Arduino pin 8

Buzzer:

buzzer to arduino pin 9

3D Files and Assembly of the Robotic Arm

Here you will find all 3D - stl files for the EEZYbotARM. As I said before, this amazing robotic arm designed by daGHIZmo. He also wrote a step-by-step assembly guide that you can find at Instructables.com, just click here.

The Code

If you want to disable the home position of your arm, just comment out the lines with "goHome();" command.

Note: You will need to change the min/max values for every servos to meet your setup.

Download the code from here and open it with Arduino IDE.

/*  Arduino Robotic Arm with Grab
 *  More info: http://www.ardumotive.com/
 *  Dev: Michalis Vasilakis Data: 12/12/2016 Ver: 1.1 */

#include <Servo.h>

//Create servo objects to control servo motors
Servo up_down;  
Servo forward_backward;
Servo rotate;
Servo grab;

//Constants
const int startBT = 7;
const int teachBT = 8;
const int buzzer = 9;
const int potForwardBackward = A3;
const int potUpDown = A2;
const int potRotate = A1;
const int potGrab = A0;
//Max and Min values for servos ! Change them to meet your setup !
const int minGrab=180;
const int maxGrab=126;
const int minRotate=0;
const int maxRotate=100;
const int minUpDown=5;
const int maxUpDown=100;
const int minForwardBackward=160;
const int maxForwardBackward=80;
//-------------------------------------//
//Variables
int readUpDown,readForwardBackward,readRotate,readGrab,readTeach,readStart;
int teachUpDown[100],teachForwardBackward[100],teachRotate[100],teachGrab[100];
boolean started =false;
int index = 1;
int stepSpeed = 20; //Change this to fo faster!

void setup() {
  //Attach Servo motors
  forward_backward.attach(3);
  up_down.attach(4);
  rotate.attach(5); //portokali xontro
  grab.attach(6);  
  //Inputs-Outputs
  pinMode(teachBT, INPUT_PULLUP);
  pinMode(startBT, INPUT_PULLUP);
  pinMode(buzzer, OUTPUT);
  //Do a smooth movement on startup, from home potion to pot position:
  readInputs();
  goHome();
  goPot();
}

void loop() {
  if (!started){
    readInputs();
    moveServos();
    if (readTeach==LOW){
      savePosition();
      tone(buzzer,500);
      delay(500);
      noTone(buzzer);
    }
    if (readStart==LOW){
      tone(buzzer,700);
      started=true;
      delay(1000);
      noTone(buzzer);
    }
  }
  else{
    goHome();
    runTeach();
  }
}

void readInputs(){
  //Read potentiometers
  readUpDown = analogRead(potUpDown);
  readUpDown = map(readUpDown,0,1023,minUpDown,maxUpDown);
  readForwardBackward = analogRead(potForwardBackward);
  readForwardBackward = map(readForwardBackward,0,1023,minForwardBackward,maxForwardBackward);
  readRotate = analogRead(potRotate);
  readRotate = map(readRotate,0,1023,minRotate,maxRotate);
  readGrab = analogRead(potGrab);
  readGrab = map(readGrab,0,1023,minGrab,maxGrab);
  //Read buttons
  readTeach = digitalRead(teachBT);
  readStart = digitalRead(startBT);
  delay(50);
}
void moveServos(){
  up_down.write(readUpDown);
  forward_backward.write(readForwardBackward);
  rotate.write(readRotate);
  grab.write(readGrab);
}

void savePosition(){
  teachUpDown[index] = readUpDown;
  teachForwardBackward[index] = readForwardBackward;
  teachRotate[index] = readRotate;
  teachGrab[index] = readGrab;
  index++;
}

void runTeach(){
  for (int i=0; i<index-1; i++){
    if (teachRotate[i] < teachRotate[i+1]){
      for (int j = teachRotate[i]; j<= teachRotate[i+1]; j++){
        rotate.write(j);
        delay(stepSpeed);
      }
    }
    else if (teachRotate[i] > teachRotate[i+1]){
      for (int j = teachRotate[i]; j>= teachRotate[i+1]; j--){
        rotate.write(j);
        delay(stepSpeed);
      }  
    }
    else{
      rotate.write(teachRotate[i]);
    }
    if (teachGrab[i] < teachGrab[i+1]){
      for (int j = teachGrab[i]; j<= teachGrab[i+1]; j++){
        grab.write(j);
        delay(stepSpeed);
      }
    }
    else if (teachGrab[i] > teachGrab[i+1]){
      for (int j = teachGrab[i]; j>= teachGrab[i+1]; j--){
        grab.write(j);
        delay(stepSpeed);
      } 
    }
    else{
      grab.write(teachGrab[i]);
    }
    if (teachForwardBackward[i] < teachForwardBackward[i+1]){
      for (int j = teachForwardBackward[i]; j<= teachForwardBackward[i+1]; j++){
        forward_backward.write(j);
        delay(stepSpeed);
      }
    }
    else if (teachForwardBackward[i] > teachForwardBackward[i+1]){
      for (int j = teachForwardBackward[i]; j>= teachForwardBackward[i+1]; j--){
        forward_backward.write(j);
        delay(stepSpeed);
      }
    }
    else{
      forward_backward.write(teachForwardBackward[i]);
    }
    if (teachUpDown[i] < teachUpDown[i+1]){
      for (int j = teachUpDown[i]; j<= teachUpDown[i+1]; j++){
        up_down.write(j);
        delay(stepSpeed);
      }
    }
    else if (teachUpDown[i] > teachUpDown[i+1]){
      for (int j = teachUpDown[i]; j>= teachUpDown[i+1]; j--){
        up_down.write(j);
        delay(stepSpeed);
      }
    }
    else{
      up_down.write(teachUpDown[i]);
    }
  }
  started=false;
}

//Change values if it's necessary...
void goHome(){
  if (readForwardBackward < 80){
      for (int j = readForwardBackward; j<=80; j++){
        forward_backward.write(j);
        delay(stepSpeed);
      }
    }
    else if (readForwardBackward > 80){
      for (int j = readForwardBackward; j>=80; j--){
        forward_backward.write(j);
        delay(stepSpeed);
      }
    }
    else{
      forward_backward.write(80);
    }
    if (readUpDown < 32){
      for (int j = readUpDown; j<=32; j++){
        up_down.write(j);
        delay(stepSpeed);
      }
    }
    else if (readUpDown > 32){
      for (int j = readUpDown; j>=32; j--){
        up_down.write(j);
        delay(stepSpeed);
      }
    }
    else{
      up_down.write(32);
    }
    if (readRotate < 0){
      for (int j = readRotate; j<=0; j++){
        rotate.write(j);
        delay(stepSpeed);
      }
    }
    else if (readRotate > 0){
      for (int j = readRotate; j>=0; j--){
        rotate.write(j);
        delay(stepSpeed);
      }
    }
    else{
      rotate.write(0);
    }
    if (readGrab < 148){
      for (int j = readGrab; j<=148; j++){
        grab.write(j);
        delay(stepSpeed);
      }
    }
    else if (readGrab > 148){
      for (int j = readGrab; j>=148; j--){
        grab.write(j);
        delay(stepSpeed);
      }
    }
    else{
      grab.write(148);
    }
    //Always start from home position
    teachForwardBackward[0]= 80;
    teachUpDown[0]=32;
    teachRotate[0]=0;
    teachGrab[0]=148;
}

void goPot(){
    if (0 > readRotate){
      for (int j = 0; j>=readRotate; j--){
        rotate.write(j);
        delay(stepSpeed);
      }
    }
    else if (readRotate > 0){
      for (int j = 0; j<=readRotate; j++){
        rotate.write(j);
        delay(stepSpeed);
      }
    }
    else{
      rotate.write(readRotate);
    }
    if (readGrab > 148){
      for (int j = 148; j<=readGrab; j++){
        grab.write(j);
        delay(stepSpeed);
      }
    }
    else if (readGrab < 148){
      for (int j = 148; j>=readGrab; j--){
        grab.write(j);
        delay(stepSpeed);
      }
    }
    else{
      grab.write(readGrab);
    }
  if (80 > readForwardBackward){
      for (int j = 80; j>=readForwardBackward; j--){
        forward_backward.write(j);
        delay(stepSpeed);
      }
    }
    else if (80 < readForwardBackward){
      for (int j = 80; j<=readForwardBackward; j++){
        forward_backward.write(j);
        delay(stepSpeed);
      }
    }
    else{
      forward_backward.write(readForwardBackward);
    }
    if (32 > readUpDown){
      for (int j = 32; j>=readUpDown; j--){
        up_down.write(j);
        delay(stepSpeed);
      }
    }
    else if (readUpDown > 32){
      for (int j = 32; j<=readUpDown; j++){
        up_down.write(j);
        delay(stepSpeed);
      }
    }
    else{
      up_down.write(readUpDown);
    }
}

Downloads

Robotic_Arm.rar

Well Done!

Great news! You have successfully complete this guide and now you have your own 3D printed Arduino Robotic Arm!
Move the arm in a position and press the teach button to save it. Make a path, when you are ready, press the start button to test it! If it succeed, you can repeat by pressing the start button! If you want to start from the beginning just power off/on the Arduino from switch.