Earlier I was having a problem with BeagleBoard Black Rev C , which I discussed in the question below.
GPIO.HIGH,LOW doesn't up LED Beagleboard
I've found the real problem. Whenever I turn any single GPIO pin (say , P8_3) , all the other GPIO pins under P8 also becomes HIGH at the same time, that's why I was having problem lighting up an LED by taking both +ve and -ve from two GPIOs from P8. Same goes for P9. In stead if I take one GPIO from P9 and make it HIGH and another from P8 and make it LOW , the LED is lighting up properly(also I checked using Multimeter and its showing potential differences properly). But the problem arises as all the other GPIOs of P9 are HIGH and all of P8 are LOW.
I want to change individual GPIOs HIGH or LOW whenever I wish. What can be the possible problem? Do I need to update the image? But I don't think that would be the reason of this problem.
EDIT: Posting the python code.
import Adafruit_BBIO.GPIO as GPIO
import time
GPIO.setup("P8_3", GPIO.OUT)
GPIO.setup("P8_5", GPIO.OUT)
while True:
GPIO.output("P8_3", GPIO.HIGH)
GPIO.output("P8_5", GPIO.LOW)