Raspberry Pi car

Hey Guys! I’m Zachary Igielman from London, I’m 13 years old, and I thought I might share some of the projects I’ve been working on with my raspberry pi. Today, I’m going to tell you how to build a raspberry pi car.

Firstly I would like to thank this forum, if it weren’t for the lovely people on here that helped me get going, I wouldn’t have been able to build these projects at all so thanks to all the forum members that have answered my questions in the past.

Before you start trying to build this, you’re going to have to install wiring pi. Instructions are here: https://projects.drogon.net/raspberry-pi/wiringpi/download-and-install/

Once you’ve installed that, you need to write and compile some c code that uses wiring pi to control some GPIO pins. Here’s the code I wrote:

CODE: SELECT ALL
#include <stdio.h>
#include <wiringPi.h>

#define left   0
#define right   2

int main (void)
{

  wiringPiSetup () ;

  int motors[4];
  motors[0]=left;
  motors[1]=right;

  int i=0;
  for (i=0; i<2; i++) {
    pinMode (motors[i], OUTPUT) ;
    digitalWrite(motors[i], LOW) ;
  }

  char input;
  int happened=0;

  for (;;) {
    happened=0;
    scanf("%c",&input);
    if (input=='a') {
      happened=1;
      digitalWrite(left, LOW);
      digitalWrite(right, HIGH);
    } else if (input=='d') {
      happened=1;
      digitalWrite(left, HIGH);
      digitalWrite(right, LOW);
    } else if (input=='w') {
      happened=1;
      digitalWrite(left, HIGH);
      digitalWrite(right, HIGH);
    } else if (input=='s') {
      printf("all off");
      digitalWrite(left, LOW);
      digitalWrite(right, LOW);
    }
  }
  return 0 ;
}

Now save the code in your default users directory (~) as car.c . Now compile it using this command (use this command to compile any c code with wiring pi):

CODE: SELECT ALL
gcc -Wall -o car car.c -lwiringPi

Now we should have a executable file called car in our default user (pi for most of us) home directory.

Next, you will have to build a circuit twice on a breadboard, with one of with wheels connected to GPIO 0 and the other wheel connected to GPIO 2. Use the ground pins on the raspberry pi for ground.

Here is the equipment list for the circuit:

Item Website to buy

      2x Motors

http://www.amazon.co.uk/15RPM-Monoaxial … otor+wheel

      1x Breadboard

http://www.amazon.co.uk/Solderless-Brea … breadboard

      6x Pin to pin jumper wires

http://www.amazon.co.uk/Assorted-Multic … breadboard

      3x Slot to pin jumped wires

http://www.amazon.co.uk/Female-Jumper-C … %2FF+150mm

      2x 2N2222 transistors

http://www.amazon.co.uk/PN2222A-NPN-Tra … rds=2n2222

      2x LEDs

http://www.amazon.co.uk/Green-Yellow-As … words=leds

      2x 330 Ohm resistors

http://www.amazon.co.uk/Resistors-330-2 … 0+resistor

      4x 2 AA battery holders

http://www.amazon.co.uk/gp/product/B000 … UTF8&psc=1

      8x AA batteries

http://www.amazon.co.uk/Duracell-MN1500 … atteries+8
Here is the circuit:

[url]pic.twitter.com/ez9pyPT9xj[/url]

Here is what pin is what:

[url]pic.twitter.com/1dkLKrhPDH[/url]

Now stick the raspberry pi, a battery back for the raspberry pi (http://www.amazon.co.uk/gp/product/B00CM5LOX8/ref=oh_details_o05_s00_i00?ie=UTF8&psc=1), the 4 AA connector packs, and the circuit on the breadboard onto a piece of wood. Stick the two motors to the underside of the back of the wood, and stick two small freewheeling caster-wheels (find them in a local DIY store) to the underside of the front.

When you plug your raspberry pi, wait a bit, then enter your username, followed by your password, followed by ‘sudo ./car’

When you press w then enter, it’ll go forward. When you press d or a, it will turn.

If the motors go the wrong direction, change round the two points they connected with the circuit.

Here are some pictures of what it should look like:
[url]pic.twitter.com/2pkLgYayov[/url]
[url]pic.twitter.com/KLQJ11dMJu[/url]
[url]pic.twitter.com/yOUVwu9xaS[/url]
[url]pic.twitter.com/3OSxv3lQsH[/url]
[url]pic.twitter.com/TqWCE1cNL5[/url]

Here is a video of it working: http://youtu.be/uQU3Os1u9OI

If you have any questions post them below along with more ideas for pi projects.

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