Raspberry pi LED Blinker

Ever since I came to Malaysia my inventive side is becoming more and more sharper. Mainly because of the Electronic components available easily in Malaysia for affordable prices. I bought a myself a Raspberry pi Model B with a Transparent casing + 8 Gb SSD Card with Preloaded Noobs for just MYR 199 (USD 60.53).

Furthermore I went to an area called Jalan Pasar in Pudu where there are lots and lots of Electronic shops which sells all sorts of components. I am waiting to do more hacks and hobby projects in the future but to start off I did a small LED Blinker project using Raspberry pi.

The following steps needs to be carried out to Run the LED Blinker in Raspberry pi.

• Login to Raspberry pi
• Open a LXTerminal window
• Download the python GPIO library

wget http://raspberry-gpio-python.googlecode.com/files/RPi.GPIO-0.4.1a.tar.gz

Untar the Tar file

tar zxvf RPi.GPIO-0.4.1a.tar.gz

Go into untared directory

cd RPi.GPIO-0.4.1a

Install GPIO for python

sudo python setup.py install

If you get errors during the installation process then you must first do the following

source/py_gpio.c:23:20: fatal error: Python.h: No such file or directory
Compilation terminated.
error: command 'gcc' failed with exit status 1

• Run apt-get update

sudo apt-get update

• The install python dev (Debian)

sudo apt-get install python-dev

• Pidora 

sudo yum -y install python-devel

After that do the following wiring where an LED ground is connected using a 1K Resistor to the Raspberry pi GND pin 6. And pin 7 GPIO 4 is connected to the LED Positive.

Then copy the following code to a text editor and save it as blink_led.py

import RPi.GPIO as GPIO 
import time 
import threading

GPIO.setmode(GPIO.BOARD) 
GPIO.setup(7, GPIO.OUT) 

class Blinker(threading.Thread):
    def __init__(self, speed, times):    
        threading.Thread.__init__(self);
        self.speed = speed;    
        self.times = times;

    def run(self):
        for i in range(0,self.times):
            print "Time : %d" % ((i+1))
            GPIO.output(7,True)
            time.sleep(self.speed)
            GPIO.output(7,False)
            time.sleep(self.speed)
        print "Blinking Complete!" 
        GPIO.cleanup()    

blinker = Blinker(1, 10)
blinker.start()

• Finally close the LXTerminal and open a new one and execute the following

sudo python blink_led.py

Everything working together

References

• http://www.thirdeyevis.com/pi-page-1.php#gpio-setup
• http://www.thirdeyevis.com/pi-page-2.php
• http://www.raspberrypi.org/phpBB3/viewtopic.php?f=31&t=13003