L293D

The L293D chip allows to control 2 DC motors using 2 PWM pins and 4 other pins

Documentation

For full documentation, please visit

Quick start

import (
	"fmt"
	"os"
	"time"

	"github.com/raspberrypi-go-drivers/l293d"
	"github.com/stianeikeland/go-rpio/v4"
)

func main() {
	err := rpio.Open()
	if err != nil {
		os.Exit(1)
	}
	defer rpio.Close()
	chip := l293d.NewL293D()
	pinEnableA := uint8(12) // PWM compatible
	pin1a := uint8(17)
	pin2a := uint8(27)

	pinEnableB := uint8(13) // PWM compatible
	pin1b := uint8(23)
	pin2b := uint8(24)
	motor1, err := chip.NewMotor(1, pinEnableA, pin1a, pin2a)
	if err != nil {
		fmt.Println("impossible to create new motor")
	}
	motor2, err := chip.NewMotor(2, pinEnableB, pin1b, pin2b)
	if err != nil {
		fmt.Println("impossible to create new motor")
	}
	// Looks like motors are not running correctly below some speed percentage
	// I experienced it below 50%
	// Set motor1 speed to 65%
	motor1.SetSpeed(65)
	// Set motor2 speed to 80%
	motor2.SetSpeed(80)
	time.Sleep(3 * time.Second)
	motor1.SetSpeed(0)
	motor2.SetSpeed(0)
}

Datasheet

L293D datasheet: https://www.ti.com/lit/ds/symlink/l293.pdf

First glance at L293D

           ______________
  1,2EN --|              |-- Vcc1
          |              |
     1A --|              |-- 4A
          |              |
     1Y --|              |-- 4Y
          |              |
    GND --|              |-- GND
          |              |
    GND --|              |-- GND
          |              |
     2Y --|              |-- 3Y
          |              |
     2A --|              |-- 3A
          |              |
   Vcc2 --|______________|-- 3,4EN

Pins	Description
1,2EN	Enable inputs 1 & 2
1A	Input 1 for motor 1
2A	Input 2 for motor 1
1Y & 2Y	To motor 1
Vcc2	5V to 36V input for motors
3,4EN	Enable inputs 3 & 4
3A	Input 1 for motor 2
4A	Input 2 for motor 2
3Y & 4Y	To motor 2
Vcc1	5V input for chip (can be taken from Raspberry Pi)

Action (identical for 3,4)	1,2EN	1A	2A	Comments
Rotation	high	high	low
Reverse rotation	high	low	high
Rotation speed	PWM	-	-
Quick stop	low	-	-	1A and 2A state doesn't matter
Free rotation	high	low	low	or high/high

To control speed, a PWM signal have to be sent to pins 1,2EN for motor 1 and 3,4EN for motor 2

Raspberry Pi compatibility

This driver has has only been tested on an Raspberry Pi Zero WH using integrated bluetooth but may work well on other Raspberry Pi having integrated Bluetooth

License

MIT License

Special thanks to @stianeikeland

This driver is based on his work in stianeikeland/go-rpio