How to make a Robotic arm with multiple servos & control it via Bluetooth?

In this video, I will show you how to control servo motors via an Android app and Bluetooth.
It’s so easy to make and hope it will be useful for you guys. If you have any question or suggestion, please feel free to comment in my youtube video and please don’t forget to like and subscribe to my YouTube channel.

Click here for the full tutorial and source code.

What is a micro servo motor?

A Servo is a small device that has an output shaft. This shaft can be positioned to specific angular positions by sending the servo a coded signal. As long as the coded signal exists on the input line, the servo will maintain the angular position of the shaft. As the coded signal changes, the angular position of the shaft changes. In practice, servos are used in radio controlled aeroplanes to position control surfaces like the elevators and rudders. They are also used in radio controlled cars, puppets, and of course, robots.

How does a micro servo work?

Servos are controlled by sending an electrical pulse of variable width or pulse width modulation (PWM), through the control wire. There is a minimum pulse, a maximum pulse, and a repetition rate. A servo motor can usually only turn 90 degrees in either direction for a total of 180-degree movement. The motor’s neutral position is defined as the position where the servo has the same amount of potential rotation in both the clockwise or counter-clockwise direction. The PWM sent to the motor determines the position of the shaft, and based on the duration of the pulse sent via the control wire; the rotor will turn to the desired position.

Component Needed:

  1. Arduino Board
  2. HC-05 Bluetooth Module
  3. Servo Motor
  4. Jumper Wires
  5. Breadboard
  6. Battery
  7. Android Device

Connections:

Note: Make sure that you circuit connections are exactly the same as in the above schematics.

The external battery VCC / GND connect to the breadboard. Connect the Arduino GND to breadboard GND.

The servo connections we use in this project are as follows:

Orange Input - Signal Input
Red Input - Power Input (VCC)
Brown Input - Ground Input(GND)

The Servo1 VCC and GND connect to the breadboard’s VCC / GND inputs.
The Servo1 Signal connects to the Arduino Digital PWM 3.
The Servo2 VCC and GND connect to the breadboard’s VCC / GND inputs.
The Servo2 Signal connects to the Arduino Digital PWM 5.
The Servo3 VCC and GND connect to the breadboard’s VCC / GND inputs.
The Servo3 Signal connects to the Arduino Digital PWM 6.
The Servo4 VCC and GND connect to the breadboard’s VCC / GND inputs.
The Servo4 Signal connects to the Arduino Digital PWM 9.

The Bluetooth module attached to the Breadboard.
The Bluetooth VCC connect to the Arduino 3.3V.
The Bluetooth GND connect to the Arduino GND.
The Bluetooth TX connect to the Arduino Digital Pin 10.
The Bluetooth RX connect to the Arduino Digital Pin 11.

Completed Design:



Reference:

  1. https://www.youtube.com
  2. https://www.phas.ubc.ca
  3. http://myandroidthings.com
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