Before writing a Python program to use the switch, you can try some experiments from the Python console.
To launch the Python Console type:
To launch the Python Console type:
# python Python 2.7.3 (default, Apr 3 2013, 21:37:23) [GCC 4.7.3 20130205 (prerelease)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>>
If you are using Ubuntu or Debian, you may need to launch python with 'sudo python' to use GPIO.
First, we need to import the library, so enter the command:
>>> import Adafruit_BBIO.GPIO as GPIO
Let's now set the pin we are going to use to be an input:
>>> GPIO.setup("P8_12", GPIO.IN)
At this point, do not press the switch, but type:
>>> GPIO.input("P8_12")
0
Now hold down the push switch and run the Python line again, by pressing the up cursor key and RETURN.
>>> GPIO.input("P8_12")
1
So, this experiment has shown us that when the key is pressed, requesting the input value from the pin will have a value of 1 and when it is not pressed, it will be 0.
Page last edited July 30, 2013
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