Rasberry Pi LED GPIO using Python

Question

In my project I invoke a python script via node.js on my Rapberrypi B+ model and what the python script does is that it turns on the BCM GPIO ports as per the python arguments passed through the node.js

$>python my_gpio.py 27 1

where 27 is the pin no and 1 is the on/off state

#my_gpio.py code


import sys
import RPi.GPIO as GPIO
GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)


f= open("GPIO","a+")


pin = sys.argv[1]
gpin = int(sys.argv[1])
state = sys.argv[2]

GPIO.setup(gpin, GPIO.OUT)

if state == "1" :
    f.write("\nPIN " +pin + " is on "+ state )
    GPIO.output(gpin, GPIO.HIGH)

else:
    f.write("\nPIN " +pin + " is off "+ state)
    GPIO.output(gpin, GPIO.LOW)

f.close
print("Done")
sys.stdout.flush()

What my objective is that I want to keep my LED HIGH until next event from the node to turn it off or turn it on

• Should I be worried of not using GPIO.cleanup()? If i use GPIO.cleanup it will turn of the LED right?
• Will there be any issue if I execute the above code like this,
  $>python my_gpio.py 27 1
$>python my_gpio.py 27 1
  ie, calling GPIO.output(gpin, GPIO.HIGH) on a GPIO.HIGH
• What are the risk i should avoid, so that i wont fry my board?

Answer 1

I would have no concern at all. My pigpio Python module has no equivalent of the cleanup method.

As far as I am aware the only GPIO libraries which have a cleanup method are RPi.GPIO and RPIO.GPIO (which is based on RPi.GPIO).

If a GPIO is already in the state you command (high when you command high, low when you command low) the command is in effect a no operation. It does no harm (or good).