In this project, the robot is controlled wirelessly through a Bluetooth App in mobile devices using the USART communication protocol.
The important component I have used is Bluetooth module HC-05. It is a class 2 module working within a range of 10 meters. Bluetooth SPP (Serial Port Protocol) module is designed for transparent wireless serial connection setup. Serial port Bluetooth module has EDR (Enhanced Data Rate) at 3 Mbps modulation with complete 2.4 GHz radio transceiver.
80 dBm sensitivity
Up to +4 dBm RF transmit power
Low Power 1.8 V Operation ,1.8 to 3.6 V I/O
USART interface with programmable baud rate
With integrated antenna
With edge connector
Motor Driver L293D:
Battery 8 V Li-on:
Voltage regulator 7805:
USART: Universal Synchronous/Asynchronous Receiver Transmitter.
The Bluetooth app sends user defined signal to the BT module which in-turn transmits it to the ATmega16. The micro-controller employs USART communication protocol to achieve the reception of signal from the Bluetooth module and processes the received signal through programmed codes and logic to give the desired output. This output helps the motor driver to control the motors.
First the Bluetooth module should be configured using “AT” commands. Then mobile and the Bluetooth module are paired. In transmission the signals are transmitted by the android app (Bluetooth Robot control) through the mobile. The transmitted signals reach the Bluetooth module wirelessly which in turn transmits it to the micro-controller (ATmega16).
The TX and RX pins of HC-05 and ATmega16 are connected respectively. The micro-controller ATmega16 acts as a receiver which is programmed to receive the transmitted signals. The micro-controller then processes the signals. For each signal corresponding output can be observed in the motor.
Problems faced and its solution
PROBLEM: Transmitted signals weren’t received by the micro-controller.
SOLUTION: Baud rate should be set as per the requirements through trial and error method.
Future Upgrades/ Enhancements of the project
The basic idea of this robot can be manipulated into a surveillance robot and also be used for remote accessing.
Use of class 1 Bluetooth module can enable the robot to amplify the range of reception up to 300 m.
The robot can be a great breakthrough in substitution of human labour at mining and other hazardous workplaces.