##Python examples

A simple module called [acmepins](https://github.com/AcmeSystems/acmepins) is available on GitHub to manage the GPIO lines
using the [sysfs method](/gpio_sysfs). 

As shown in the following examples with this module is possible to manage the GPIO states using directly the board pin names or
the Atmel chip pin names or the GPIO Kernel IDs.

<ul class="nav nav-tabs">
	<li class="nav active"><a href="#acquaa5" data-toggle="tab">Acqua A5</a></li>
	<li class="nav"><a href="#ariag25" data-toggle="tab">Aria G25</a></li>
	<li class="nav"><a href="#ariettag25" data-toggle="tab">Arietta G25</a></li>
	<li class="nav"><a href="#foxg20" data-toggle="tab">Fox Board G20</a></li>
</ul>

<div class="tab-content">
	<div class="tab-pane fade in active" id="acquaa5">
		<br/>
		<img src="gpio_acquaa5.jpg" class="float"/>
	</div>
	<div class="tab-pane fade in" id="ariag25">
		<br/>
		<img src="gpio_ariag25.jpg" class="float"/>
	</div>
	<div class="tab-pane fade in" id="ariettag25">
		<br/>
		<img src="gpio_ariettag25.jpg" class="float"/>
	</div>
	<div class="tab-pane fade in" id="foxg20">
		<br/>
		<img src="gpio_foxg20.jpg" class="float"/>
	</div>
</div>



###An output example: a Blinking led

This example will blink a led wired to a output line

<pre class="prettyprint">
from acmepins import GPIO
from time import sleep

#FOX Board G20 example
led = GPIO('J7.3','OUTPUT') 

#Aria G25 example
#led = GPIO('W9','OUTPUT') 

#Arietta G25 example
#led = GPIO('J4.29','OUTPUT') 

#Acqua A5 example
#led = GPIO('J3.32','OUTPUT') 

while True:
	led.on()
	sleep(1)
	led.off()
	sleep(1)
</pre>

###An input example: Reading a push button

there are two ways o read a GPIO input state:

* Checking inside a loop the input state (polling mode)
* Setting a callback function for any input state change (event mode)

###Polling mode

<pre class="prettyprint">
from acmepins import GPIO
from time import sleep

#FOX Board G20 example
Button=GPIO('J7.5','INPUT')

#Aria G25 example
#Button=GPIO('W15','INPUT')

#Arietta G25 example
#Button=GPIO('J4.28','INPUT')

#Acqua A5 example
#Button=GPIO('J3.33','INPUT')

i=0
while True:
	sleep(1)
	i+=1
	print i
	if Button.digitalRead()==0:
		print "Pressed"
		while Button.digitalRead()==0:
			pass   
</pre>

###Event mode

<pre class="prettyprint">
from acmepins import GPIO
from time import sleep

def event_handler():
	print "Input changed"

#FOX Board G20 example
Button=GPIO('J7.5','INPUT')

#Aria G25 example
#Button=GPIO('W15','INPUT')

#Arietta G25 example
#Button=GPIO('J4.28','INPUT')

#Acqua A5 example
#Button=GPIO('J3.33','INPUT')

Button.set_edge("both",event_handler)

i=0
while True:
	print i
	i=i+1
	sleep(0.5)
</pre>

One of three conditions can be checked:

* **falling**: the callback function is called when the signal goes from 1 to 0 (Not available on FOX G20)
* **rising**: the callback function is called when the signal goes from 0 to 1 (Not available on FOX G20)
* **both**: the callback function is called on any status change