Using Pi GPIO for other things other than controllers

[sirus555]

Hi,

Ive just stumbled on this brilliant OS after search for issues I am having with my own custom build.
Currently I am working on a project which brings kodi, moonlight and emualtion station into one but am having trouble with the controller registers. I am looking to try out this build as I read on git that usb controllers are automatically recongised. (I hope this is true).

However, my question lies around the pi's gpio. I am looking to hook up a fan and some leds lights that imitate the pwr and act leds on the pi, ready to go into a custom box. I was just curious is it possible to do this on the OS?

[Substring]

Sure you can ! Our python gpio God @supernature2k can do anything you need

2 things :

• if you search ni the forum, you'll find quite some ressources concerning that
• we are also working on giving gpios other super powers : reset (when available) or kill an emulator, use retroarch network commands ... Prety amazing stuff in fact

[lackyluuk]

@sirus555 I have a working fan script running in my recalbox. It just turns the fan on at a defined cpu temperature for a certain time to cool it down.
I could post it here when I am at home (if still needed)

[sirus555]

Thanks @subs

Thanks @lackyluuk that would be much appreicated.

[lackyluuk]

Here is an example with GPIO pin 14 for controlling the fan. The indents might not be correct I had a little trouble with copy/paste the code
Hope I can help you with this

#!/usr/bin/env python

import os
import time
import RPi.GPIO as GPIO

GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)
#Set max. temperature of CPU
TEMP_MAX = 67
ON_TIME = 200
#Set pin 14 as transistor gate
GATE = 14
#Set pin 14 as an output and shut down
GPIO.setup(GATE, GPIO.OUT)
GPIO.output(GATE, False)

def getCPUtemperature():
	 res = os.popen('vcgencmd measure_temp').readline()
	return(res.replace("temp=","").replace("'C\n",""))

while True:

		temp_float = float(getCPUtemperature())

	try:
		if (temp_float > TEMP_MAX):
			# ein
			GPIO.output(GATE, True)
			time.sleep(ON_TIME)
			# aus
			GPIO.output(GATE, False)
		else:
			GPIO.output(GATE, False)
		
except KeyboardInterrupt:
	print float(getCPUtemperature())
	print "power off fan..."
	GPIO.output(GATE, False)
	print "cancelling..."

Here you will also find a small drawing for the transistor etc
https://forum.recalbox.com/topic/3704/push-button-on-off-script-problems/11

[marchegiano]

@lackyluuk Thanks bud, super neat.