BeagleBone 4-bit counter

BeagleBone 4-bit counter

After I got my BeagleBone Black I decided to make a simple 4-bit binary LED counter just to get to know it better. I found video tutorials from Derek Molloy a very useful resource. But I need to work more on getting to understand pin configuration. In my first version I used pin "P9_12" for  MSB of counter. I'm almost certain that it used to work. Now while working on this blog post it didn't work. The LED was always on. Eventually I had to move MSB to "P8_13" and then it worked.
Below is Fritzing breadboard layout of my circuit. Fritzing produces some nice output for documentation of breadboard projects. But I need to use it more to get used to it.This relatively simple circuit took me quite some time to get right and I made a lot of mistakes on the way.

The code is written in Python using Adafruit_BBIO.GPIO library and is available from GitHub.

	import Adafruit_BBIO.GPIO as GPIO
	import time
	def setled(i):
	print i
	if((i&0x1)==0x1):
	GPIO.output("P8_26",GPIO.HIGH)
	else:
	GPIO.output("P8_26",GPIO.LOW)
	if((i&0x2)==0x2):
	GPIO.output("P9_23",GPIO.HIGH)
	else:
	GPIO.output("P9_23",GPIO.LOW)
	if((i&0x4)==0x4):
	GPIO.output("P9_15",GPIO.HIGH)
	else:
	GPIO.output("P9_15",GPIO.LOW)
	if((i&0x8)==0x8):
	GPIO.output("P8_13",GPIO.HIGH)
	else:
	GPIO.output("P8_13",GPIO.LOW)
	def bbled():
	GPIO.setup("P8_26", GPIO.OUT)
	GPIO.setup("P9_23", GPIO.OUT)
	GPIO.setup("P9_15", GPIO.OUT)
	GPIO.setup("P8_13", GPIO.OUT)
	for i in range(16):
	setled(i%16 )
	time.sleep(1)
	if __name__ == "__main__":
	bbled()

view raw bbled.py hosted with ❤ by GitHub

The final result can be seen in video below.