EFA:IC:L293D

H-Bridges

The transistor only allows you to control a DC motor in one direction. If you want to change the direction also, you need to use an H-Bridge circuit.

L293D

The L293D is a good, basic H-Bridge IC suitable for controlling DC motors and bipolar stepper motors. It contains two full H-Bridges, so you can control 2 DC motors or one stepper motor with one chip.

  • Supply voltage: 4.5V–36V
  • Output current: 600 mA
  • Peak output current: 1.2A
  • Built-in kickback diodes
  • Pin-compatible with the SN754410

Using the L293D With Arduino

Download a PDF file of the schematics and drawings: L293D_full

The enable pin that is connected to pin 9 on the Arduino controls the H-Bridge on/off. The pins 10 and 11 on the Arduino control the motor direction. This table will help you figure out how to control the motor. Note that this is just for one side of the H-Bridge

PIN 9 (ENABLE) PIN 10 PIN 11 FUNCTION
HIGH HIGH LOW Motor turns left
HIGH LOW HIGH Motor turns right
HIGH HIGH HIGH Motor stops
HIGH LOW LOW Motor stops
LOW HIGH/LOW HIGH/LOW Motor stops