Raspberry Pi - Controlling DC Motor - Both Directions

The connection of your transistors makes no sense if you intent to make a H-bridge. (all NPN transistors is not a common solution, (there are ways to do it for sure), and will not work the way you connected them)

Read up on the theory, check this article : http://www.robotroom.com/BipolarHBridge.html

And read this :http://learn.adafruit.com/adafruit-raspberry-pi-lesson-9-controlling-a-dc-motor/overview

I would suggest a H-Bridge IC (easily found eg. L293D or similar), and some protection (opto or resistors) between your IO ports and the power circuits.

Also, look at mosfet variants, these need less cooling and can handle more current.

Good luck,

Edwin van den Oetelaar.

I have managed to run DC motors succesfully using the L293D.

Thanks,

I decided to go witht he L293D. I just have one question. Does the VCC1 pin (top-right) need to provide power to something. In other words, the Pi is powered by other means, so can I just leave that pin alone?

Ok, here is what I have to far:

Any suggestions?

Hi Nicholas,

If you want to control a motor with RPI and L293D, Adafruit has a tutorial here, (using the same device) including wiring diag.

I have a project that depended on changing from a Pololu qik 2s9v1 motor controller with a simple logic level motor driver (L293D). It works great and here is my code:

/*
 * L293D_rpi_motor test.cpp
 * 
 * Copyright 2017 Brandon Williams <brandon.w2055@gmail.com>
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301, USA.
 * 
 * 
 */

/* Raspberry Pi Model B2 Pinmap
 +-----+-----+---------+------+---+-Model B2-+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 |     |     |    3.3v |      |   |  1 || 2  |   |      | 5v      |     |     |
 |   2 |   8 |   SDA.1 | ALT0 | 1 |  3 || 4  |   |      | 5V      |     |     |
 |   3 |   9 |   SCL.1 | ALT0 | 1 |  5 || 6  |   |      | 0v      |     |     |
 |   4 |   7 | GPIO. 7 |   IN | 1 |  7 || 8  | 1 | ALT0 | TxD     | 15  | 14  |
 |     |     |      0v |      |   |  9 || 10 | 1 | ALT0 | RxD     | 16  | 15  |
 |  17 |   0 | GPIO. 0 |   IN | 0 | 11 || 12 | 0 | IN   | GPIO. 1 | 1   | 18  |
 |  27 |   2 | GPIO. 2 |   IN | 0 | 13 || 14 |   |      | 0v      |     |     |
 |  22 |   3 | GPIO. 3 |   IN | 0 | 15 || 16 | 0 | IN   | GPIO. 4 | 4   | 23  |
 |     |     |    3.3v |      |   | 17 || 18 | 0 | IN   | GPIO. 5 | 5   | 24  |
 |  10 |  12 |    MOSI |   IN | 0 | 19 || 20 |   |      | 0v      |     |     |
 |   9 |  13 |    MISO |   IN | 0 | 21 || 22 | 0 | IN   | GPIO. 6 | 6   | 25  |
 |  11 |  14 |    SCLK |   IN | 0 | 23 || 24 | 1 | IN   | CE0     | 10  | 8   |
 |     |     |      0v |      |   | 25 || 26 | 1 | IN   | CE1     | 11  | 7   |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 |  28 |  17 | GPIO.17 |   IN | 0 | 51 || 52 | 0 | IN   | GPIO.18 | 18  | 29  |
 |  30 |  19 | GPIO.19 |   IN | 0 | 53 || 54 | 0 | IN   | GPIO.20 | 20  | 31  |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+-Model B2-+---+------+---------+-----+-----+


 */

/*
    The following software is a test for the L293D motor driver
as a greater project objective to integrate this IC into a shield for
the raspberry pi.

Pinout Map [L293D pin# (Function) -- Rpi pin# (Name)]
*     
    1 (Enable 1)   --  11 (GPIO 2)
    2 (Input 1)    --  13 (GPIO 3)
    3 (Output 1)
    4 (GND)
    5 (GND)
    6 (Output 2)
    7 (Input 2)    --  15 (GPIO 4)
    8 (Control V)  --  1 (5V)
    9 (Enable 2)   --  /
    10 (Input 3)   --  /
    11 (Output 3)
    12 (GND)
    13 (GND)
    14 (Output 4)
    15 (Input 4)   --  /
    16 (Supply V)
*
Truth Table for a Single Motor (F=forward, R=reverse, S=stop)
* Enable | Input 1 | Input 2 | Output 1 | Output 2| Dir.
*    H   |    H    |    L    |     H    |     L   |  F  
*    H   |    L    |    H    |     H    |     L   |  R   
*    L   |    /    |    /    |     /    |     /   |  S   
*/
#include <stdio.h>
#inlcude <wiringPi.h>

#define ENABLEPIN 0
#define INPUT1 2
#define INPUT2 3

int main void{
    printf("Raspberry Pi - Motor Control L293D");
    
    wiringPiSetup();
    
    pinMode(ENABLEPIN, OUTPUT);
    pinMode(INPUT1, OUTPUT);
    pinMode(INPUT2, OUTPUT);
    
    digitalWrite(ENABLEPIN, 1); /*Enable Motor 1 channel active*/
    
    for(int i=0; i>=0; i++){
        delay(500);
        printf("Forward Motion");
        digitalWrite(INPUT1, 1); /*Begin Forward Motion*/
        digitalWrite(INPUT2, 0);
        delay(1500);
        printf("Reverse Motion");
        digitalWrite(INPUT1, 0); /*Begin Reverse Motion*/
        digitalWrite(INPUT2, 1);
    }
    /* Stop Motors and Disable Motor 1 */
    digitalWrite(INPUT1,0);
    digitalWrite(INPUT2,0);
    digitalWrite(ENABLEPIN,0);
    
    return 0;
}