GPIO Introduction

First order of business is to import some libraries to help send/receive signals to/from the GPIO pins of the Raspberry Pi.



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import RPi.GPIO as GPIO
import time

The following code will set the mode to a Broadcom pin layout (which seems to be what we want), and set up our GPIO pin 25 as an output pin.



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GPIO.setmode(GPIO.BCM)

Lighting an LED



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outpin = 25
GPIO.setup(outpin, GPIO.OUT)



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GPIO.output(outpin, True)  # Let there be light



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GPIO.output(outpin, False)  # Turn it off

Multiple LEDs



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outpins = [25, 26]
for pin in outpins:
    GPIO.setup(pin, GPIO.OUT)



In [8]:

    
for pin in outpins:
    GPIO.output(pin, True) # hello world?
    time.sleep(0.2)        # a bit of delay between lighting each LED



In [9]:

    
for pin in outpins:
    GPIO.output(pin, False) # goodbye world?
    time.sleep(0.2)



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for i in range(20):
    for pin in outpins:
        GPIO.output(pin, True) # hello world?
        time.sleep(0.2)        # a bit of delay between lighting each LED
    for pin in outpins:
        GPIO.output(pin, False) # goodbye world?
        time.sleep(0.2)



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GPIO.cleanup()



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