====== RPI - GPIO ======

Utilisations : entrées, sorties, ...


===== Ligne de commande =====
 Elevate your permissions to root user to allow IO access


sudo -i

Setup to control pin as output

Substitute 23 in the following commands for your GPIO number (GPIO, not pin number)


echo "23" > /sys/class/gpio/export
echo "out" > /sys/class/gpio/gpio23/direction

Control Output State


echo "1" > /sys/class/gpio/gpio23/value
echo "0" > /sys/class/gpio/gpio23/value

Setup to read pin as an input

Substitute 23 in the following commands for your GPIO number (GPIO, not pin number)


echo "23" > /sys/class/gpio/export
echo "in" > /sys/class/gpio/gpio23/direction

Read its state


cat /sys/class/gpio/gpio23/value

To Release A Pin Afterwards


echo "23" > /sys/class/gpio/unexport

===== Avec Python =====
Avec la  biblio RPI.gpio et la biblio gpiozero : 
Here’s a list of devices which currently supported:
  * LED (also PWM LED allowing change of brightness)
  * RGB LED
  * Buzzer
  * Motor
  * Button
  * Motion Sensor
  * Light Sensor
  * Analogue-to-Digital converters MCP3004 and MCP3008
  * Robot


[[https://www.youtube.com/watch?v=q_NvDTZIaS4|Vidéo d'introduction]]

**Ressources**
  * La documentation de [[https://gpiozero.readthedocs.io/en/v1.3.1/recipes.html#button|gpiozero]]
  * [[https://www.raspberrypi.org/blog/gpio-zero-a-friendly-python-api-for-physical-computing/|gpiozero - tutorial]]
  * Article [[materiel:rpi:pwm:accueil|RPI - PWM]]



=====Pins=====
<WRAP group>
<WRAP half column>{{:materiel:rpi:gpio:pi3_gpio.png?500|}} **RPI 3**</WRAP>
<WRAP half column>{{:materiel:rpi:raspberry_pins.png|}} **RPI B+**</WRAP>
</WRAP>

===== Sorties =====
<WRAP group>
<WRAP half column>
{{:materiel:rpi:gpio:led-gpio17-500x297.png|}}
</WRAP>

<WRAP half column>
<code python>
from gpiozero import LED
from time import sleep

led = LED(17)

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


===== Entreés =====

<WRAP group>
<WRAP half column>
{{:materiel:rpi:gpio:rpi-button.png|}}
</WRAP>

<WRAP half column>
<code python>
from gpiozero import Button
mybutton = Button(2)
mybutton.wait_for_press()
print('You pushed me')
</code>
</WRAP>
</WRAP>


**Lancer une fonction**
<code python>
from gpiozero import Button
from signal import pause
   
def say_hello():
	print("Hello!")

button = Button(2)
button.when_pressed = say_hello
    
pause()
</code>

**Lancer un programme**
<code python>
from gpiozero import Button
from signal import pause
import subprocess

button = Button(2)
button.wait_for_press()
subprocess.call(['omxplayer test.mkv'], shell=True)
</code>

**Déclencher deux sons avec deux boutons**
Avec Pygame : http://nerdparadise.com/tech/python/pygame/basics/part3/

<WRAP center round info 60%>
  * FORMATS MP3 POSSIBLES AVEC pygame.mixer.music.load("Got-inspiration.mp3")
  * FORMATS WAVE AVEC sound =  pygame.mixer.Sound("/usr/share/scratch/Media/Sounds/Electronic/Zoop.wav"). The Sound can be loaded from an OGG audio file or from an uncompressed WAV.
</WRAP>

<code python>
from gpiozero import Button
from signal import pause
import pygame

b1 = Button(2)
b2 = Button(3)

pygame.mixer.init()
son1 =pygame.mixer.Sound('/usr/share/scratch/Media/Sounds/Electronic/Zoop.wav')
son2 =pygame.mixer.Sound('/usr/share/scratch/Media/Sounds/Electronic/Laser1.wav')

def launch_sound1():
    son1.play()

def launch_sound2():
    son2.play()

b1.when_pressed = launch_sound1
b2.when_pressed = launch_sound2

pause()
</code>



**Même chose en plus souple**
<code java>
from gpiozero import LED, Button
from signal import pause
import pygame


button1 = Button(2)
button2 = Button(3)
led = LED(17)
pygame.mixer.init()
monson1 =pygame.mixer.Sound('/usr/share/scratch/Media/Sounds/Electronic/Zoop.wav')
monson2 =pygame.mixer.Sound('/usr/share/scratch/Media/Sounds/Electronic/Laser1.wav')

# dictionnaire clé/valeur pour lister les sons
sounds = {button1: monson1,
          button2: monson2}

def stateON(button):
    sounds[button].play()
    led.on()

def stateOFF(button):
    sounds[button].stop()
    led.off()  

def btntest():
    # parcours l'ensemble des clés du dictionnaire sounds
    for button in sounds.keys():
        # when_pressed envoie apr defaut le bouton en tant qu'argument de la fonction stateON / stateOFF
        button.when_pressed = stateON
        button.when_released = stateOFF

btntest()
pause()
</code>




===== Entrée / Sortie =====

<WRAP group>
<WRAP half column>
{{:materiel:rpi:gpio:rpi-gpio-button-led.png|}}
</WRAP>

<WRAP half column>
<code python>
from gpiozero import LED, Button
from signal import pause
led = LED(17)
button = Button(2)
button.when_pressed = led.on
button.when_released = led.off
pause()
<code>
</WRAP>
</WRAP>



-----


FIXME








==== Installation ====

  sudo apt-get install python-setuptools
  sudo easy_install -U RPIO

Comme on a accès aux couches physiques avec ce type de module, il faut lancer python ou idle (l'interpréteur python) en mode administrateur :

  sudo idle &

==== Exemples ===
**Exemple de code en python (http://explainingcomputers.com/rasp_pi_robotics.html) :**
<code python>
import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BOARD)
GPIO.setup(7,GPIO.OUT)
for x in range(0,3):
    GPIO.output(7,True)
    time.sleep(1)
    GPIO.output(7,False)
    time.sleep(1)
GPIO.cleanup()
</code>


**Autre exemple en contrôlant des moteurs à courant continu via un L298 :**

{{:materiel:rpi:rpi-robotics2.png?400|}}