Introduction of L293D
With a 16-pin DIP package, L293D integrates a bipolar H-bridge circuit internally. The bipolar PWM method has many advantages: continuous current, four-quadrant operation of motors, smoothness during low speed, micro-vibration currents when the motor stops (which as dynamic lubricator can eliminate static friction during the motor forward-inverse rotation), etc.
L293D generates enable signals by internal logic circuit. The input of H-bridge circuit can be used to define the direction of the motor rotation when the enable signals, for PWM. Besides, it integrates two H-bridge circuits onto one chip, which means one chip can control two motors simultaneously.
Each motor needs three kinds of control signals: EN12, IN1, and IN2. Within, EN12 are enable signals, when IN1 and IN2, motor rotation direction ones. When IN1 and IN2 are 1 and 0 respectively, the motor rotates forward; or else, it rotates inversely. Connect of the PWM pins with pin EN12 and then you can change the rotational speed of the motor by adjusting the duty cycle of PWM. Connect one of I/O pins with pin IN1 and IN2 with the inverter 74HC14, so as to control the forward and reverse rotation of the motor.
Application
The module can be used as the driver board for robots and smart cars.
More details can be found in WIKI.
Component List
- 1 * Motor Driver Shield
Note:
The shield itself does not support any functions; it needs to be plugged onto a Uno board for normal use.
For protection of the shield, PLEASE use an EXTERNAL power supply!
