February 16, 2014 § 2 Comments
I will discuss the circuit diagram and mechanical description of the bluetooth robot now.
Actually, It’s not a robot. It’s some kind of remote controlled car that can be controlled over bluetooth from a laptop or PC.
The power of the microcontrollers are too low compared to the modern laptop or desktop. There is no huge computing power, no scope for image processing, no scope for huge amount of data logging, no scope for multitasking(Although there is some multitasking OS available for microcontrollers, They are complex, Time consuming, Requires a lot processing power to achieve multitasking.) and other limitations.
So, My concept was Why not build a slave device that is controlled from a central server that has huge processing power.
You can say that why not build such big robot that can carry a whole laptop inside it? Then the answer maybe The CPU requires a lot more power, Adds an extra weight to carry, has restrictions for harsh/rough environments and more…
OK, Enough now i will come to the main point.
The robot chasis is like normal tank principle. It has two treads attached with two geared motors. When both motors move forward, the chasis will go forward, opposite applies for backward movement, and when one motor is running and the other one is stopped, it will take a turn. I will add detailed images about the robot chasis later.
Now, about the circuit..
The heart of the circuit is the atmega8 microcontroller, which gets commands from the hc-06 bluetooth module and drives a l293d motor controller Which controls the speed and direction of the motor. The speed of the motor is controlled by pwm dc motor speed control method. You can get brief of it into the codes.
A correction. I have drawn this circuit with fritzing. The HC-06 bluetooth module i can’t found in fritzing but used here RN-41 module. The connection is same for HC-06.