Published February 3, 2018 © GPL3+

Bluetooth Controlled Pick And Place Robot

We have built a 2WD robot with a robotic arm on it controlled from a mobile app over Bluetooth connection. Use this step-by-step tutorial!

IntermediateFull instructions provided2 days34,703

Bluetooth Controlled Pick And Place Robot

Things used in this project

Hardware components

Arduino UNO

2 DOF Robot Arm with Gripper and Base

HC-05 Bluetooth Module

adafruit motor shield

2WD Smart Robot Car Chassis Kit

NiMH Rechargeable Battery (5V-1500mAh)

7.4V Battery

Mini Breadboard

Jumper wires (generic)

Software apps and online services

Arduino IDE

MIT App Inventor

Hand tools and fabrication machines

Soldering iron (generic)

Story

Intro

The Robot First Move

This tutorial demonstrates how to build a pick and place robot controlled with your Android smartphone. We have built a mobile app using the MIT App Inventor platform. In this tutorial, we will talk about each part of this project separately. We will talk about:

1 How to Control a Servo Motor
2 How to Control a DC Motor
3 How to Use the Bluetooth Module
4 How to Control Your Robot with Your Mobile Phone

So I hope this tutorial covers all your needs to build your bot.

The Scenario

First of all, we must to know how the robot will take orders. We are using a Bluetooth module which will be connected to a mobile app, which we will build afterward. For now we need to know that we will send our command to the robot with our mobile using the Bluetooth connection.

the robot

Hardware

The kit requires some simple assembly, but it does take some time. Follow the instructions included with your kit for assembly,

At the end of the assembly it should look like this:

2WD Chassis Car Kit

The Free Wheel

The Motor Shield allows you to talk with your motors. If you connect the motors directly to the Arduino board, it will start a fire! because every motor needs at least 80MA but the max current the digital Arduino pin can provide is 40MA, so DO NOT try to connect the motor directly to your Arduino board.

The motor shield helps you to control the direction of your motor (e.g. move FORWARD, BACKWARD, and RELEASE).

The Motor Shield

The Motor shield allows you to control up to 4 bi-directional DC motors with individual 8-bit speed selection (so, about 0.5% resolution).

You can solder some pin headers on the top of the shield to be able to use the Arduino pins.

The Pin Header

Sldered Pin Header on the shield pins

You need to stick your motor shield above your Arduino board like this:

stick the motor shield on the arduino board

The Bluetooth module: it's the channel between the pilot and the robot to send orders and take actions.

bluetooth module HC-05

It has 6 pins; we will use only the middle four pins (RX-TX-GND-+5):

bluetooth module pins

We will connect:

+5 on the Bluetooth module to the 5v on the Arduino
GND on the Bluetooth module to the GND on the Arduino
Rx on the Bluetooth module to the Tx on the Arduino
Tx on the Bluetooth module to the Rx on the Arduino

bluetooth module connections

NOTE: WHY Rx to Tx and Tx to Rx?

Because the Bluetooth module sends data (Tx) and the Arduino receives this Data (Rx).

One Sends And The Other Receives

4) The Servo Motor has 3 wires: red (Positive), brown (Negative), yellow or orange (Signal).

Note: DO NOT connect the Positive and Negative of the Servo Motors to the 5V and GND of the Arduino board. The Arduino board will start a fire due to the high current absorbed by the motors; use the external battery.

The Red wire to the Positive of the external battery
The Brown wire to the Negative of the external battery
The Orange wire to any digital (PWN) pin on the Arduino

NOTE: Don't forget to make the GND of the battery and the GND of the Arduino a common, make it by connecting each GND to each other.

5) The DC Motors

You need to solder some wires on the Motor Terminals to be able to use these motors.

The DC Motor has no polarity. There is no Positive and no Negative. If you reverse your motor connections, the motor's direction of movement will change.

The Motor Terminals

After you solder the Motor Terminals, connect these terminals to the Motor Shield.

NOTE: In the Arduino code, I used Motor 1 and Motor 2 - not Motor 3 and Motor 4.

The Schematic

How to Connect the Robot Motors and the battery with the motor driver.

How to Connect the Arm servo Motors and the battery with the Arduino board.

How to Connect the bluetooth module with the Arduino board.

NOTE: disconnect(remove the RED WIRE +5 pin) the bluetooth module while uploading the code to the Arduino board. Then reconnect it back after the uploading process is done.

Code

Pick And Place Robot Arduino Code

#include<AFMotor.h>
#include<Servo.h>
AF_DCMotor motorR(1);
AF_DCMotor motorL(2);
Servo elbowServo;
Servo gripperServo;
int command;

void setup() {

gripperServo.attach(9);
elbowServo.attach(10);
Serial.begin(9600);
motorR.setSpeed(255);
motorL.setSpeed(255);
}

void loop() {
command = Serial.read();

                                        /*     ARM Code    */

if(command>=1 && command <=180)   //elbow servo move according to the thumb position on the mob app between 0 -- 180  .
{
  elbowServo.write(command);
}
else if (command == 205)    //Gripper Move To Angle 0
{
  gripperServo.write(0);
}
else if (command == 206)    //Gripper movw to angle 90
{
  gripperServo.write(90);  
}
else if (command == 207)    //gripper move to angle 180
{
  gripperServo.write(180);
}

                                            /*  CAR CODE  */  

else if (command == 200)
{
  motorR.run(FORWARD);
  motorL.run(FORWARD);
}
else if(command == 201)
{
  motorR.run(FORWARD);
  motorL.run(BACKWARD);  
}
else if(command == 202)
{
  motorR.run(RELEASE);
  motorL.run(RELEASE);  
}
else if(command == 203)
{
  motorR.run(BACKWARD);
  motorL.run(FORWARD);  
}
else if(command == 204)
{
  motorR.run(BACKWARD);
  motorL.run(BACKWARD);  
}
else if(command == 0)
{
  motorR.run(RELEASE);
  motorL.run(RELEASE);  
}
}

Credits

Ahmed Ibrahim Ahmed

11 projects • 106 followers

An Egyptian Computer Engineering Student, Robotics And Embedded Systems Geek.

Bluetooth Controlled Pick And Place Robot

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Intro

The Scenario

Hardware

One Sends And The Other Receives

The Schematic

Schematics

The Mobile App For This Robot

Code

Pick And Place Robot Arduino Code

Credits

Ahmed Ibrahim Ahmed

Comments

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Bluetooth Controlled Pick And Place Robot

Bluetooth Controlled Pick And Place Robot

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Intro

The Scenario

Hardware

One Sends And The Other Receives

The Schematic

Schematics

The Mobile App For This Robot

Code

Pick And Place Robot Arduino Code

Credits

Ahmed Ibrahim Ahmed

Comments

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