1. DC MOTOR INTERFACING
WITH 8051 MICROCONTROLLER
PRESENTED BY
UMAR SHU’AIBU

2. DC MOTOR INTERFACING WITH 8051 MICROCONTROLLER USING l293
C K Pithawala College of Engineering and Technology
DC MOTOR INTERFACING WITH 8051 MICROCONTROLLER USING l293
Group Number-07
Patel Abhijeet :
Patel Ankur :
Patel Arth :
Patel Axil :
Patel Dharmil :
Faculty Guide : -

3. introduction
Interfacing DC motor to 8051 forms an essential part in designing embedded robotic projects. A well designed 8051-DC motor system has essentially two parts. Firstly an 8051 with the required software to control the motor and secondly a suitable driver circuit. Most of the DC motors have power requirements well out of the reach of a microcontroller and more over the voltage spikes produced while reversing the direction of rotation could easily damage the microcontroller. So it is not wise to connect a DC motor directly to the microcontroller. The perfect solution is to use a motor driver circuit in between the microcontroller and the DC motor. The driver circuit used in this presentation are:- a)L293 IC b) H-bridge

4. using l293 driver to interface dc motor with 8051
L293 is a dedicated quadruple half H bridge motor driver IC available in 16 pin package. L293 has a current capacity of 600mA/channel and has supply voltage range from 4.5 to 36V DC. They are fitted with internal high speed clamp diodes for inductive spike protection. Other good features of L293 are high noise immunity, internal ESD protection, thermal shutdown, separate input supply for each channel etc. The pin out of L293 motor driver is shown in the figure below.

5. Below is the diagram that show how l293 is connected to 8051 for bi- directional control, and also the truth table indicating the direction of motion of the motor depending on the input from microcontroller to l293.

7. P1.0
P1.1
State of the motor
stop or break 1
Motor move anti-clockwise
Motor move clockwise
Stop or break
Three pins are needed for interfacing a DC motor (A, B, Enable). If you want the o/p to be enabled completely then you can connect Enable to VCC and only 2 pins needed from controller to make the motor to rotate either clockwise or anti-clockwise depending on the output from microcontroller.

8. Thank you