14-02-2013, 12:44 PM
Wireless hand gesture controlled bot
Wireless hand.docx (Size: 443.89 KB / Downloads: 39)
Introduction:
The objective of our project is to control the directions of an autonomous robot wirelesslythrough hand gestures using an accelerometer sensor MMA7361L. The use of such a sensor is vast in the field of robotics.
Components Required:
1. An Autonomous Car
2. One motor driver circuit
3. Two Arduino Boards
4. An Accelerometer(MMA7361L)
5. One Wireless Module
MOTOR DRIVER CIRCUIT L293D
We interface and control DC motors with a microcontroller. Usually H‐bridge is preferred in interfacing a DC motor. At present, IC manufacturers have H‐bridge motor driver available in the market. L293D is mostly used H-bridge driver IC amongst them.
WORKING THEORY OF H-BRIDGE:
The name "H‐Bridge" is derived from the actual shape of the switching circuit which controls the motion of the motor. It is also known as "Full Bridge. There are four switching elements named as "High side left", "High side right", "Low side right", "Low side left". When these switches are turned on in pairs motor changesits direction accordingly.
If we switch on High side left and Low side right then motor rotate in forward direction, as current flows from power supply through the motor coil goes to ground via switch low side right. This is shown in the figurebelow.
L293D H-BRIDGE MOTOR DRIVER:
L293D is a dual H‐Bridge motor driver, so with one IC we can interface two dc motors which can be controlled in both clockwise and counter clockwisedirection and if you have motor with fix direction of motion.L293D has output current of 600mA and peak output current of 1.2A per channel. Moreover forprotection of circuit from back EMF output diodes are included within the IC. The output supply (VCC2) has a wide range from 4.5V to 36V,which has madeL293D a best choice for DC motor driver