I connected my rpi3 to a 10" touchscreen. I connected the backlight of the touchscreen to a relay which I'm controlling via the GPIO pins. This is working fine for the first couple of minutes. But after for a while (>15 minutes) there seems to go something wrong: the backlight turns on/off unexpectetly.
I have a python script running on the background with a timer. Of you touch the touchscreen, the backlight turns on. After 120 seconds of not touching the screen, the backlight turns off again. It remains off until you touch the screen again.
This is my source code:
#!/usr/bin/env python from threading import Timer import os import time import evdev from evdev import InputDevice,categorize,ecodes def blank_screen(): global backlight backlight = 0 #print 'Backlight OFF (', time.ctime(), ')' os.system("/home/pi/scripts/gpio_off.py") # Call blank_screen in 120 seconds backlight = 1 timeout = 120 t = Timer(timeout,blank_screen) t.start() device = InputDevice('/dev/input/event0') for event in device.read_loop(): if (backlight == 0): backlight = 1 #print 'Backlight ON' os.system("/home/pi/scripts/gpio_on.py") else: t.cancel() t = Timer(timeout,blank_screen) t.start()
#!/usr/bin/env python import time import RPi.GPIO as GPIO GPIO.setwarnings(False) GPIO.setmode(GPIO.BCM) GPIO.setup(17, GPIO.OUT) GPIO.output(17, GPIO.HIGH) time.sleep(0.25)
#!/usr/bin/env python import time import RPi.GPIO as GPIO GPIO.setwarnings(False) GPIO.setmode(GPIO.BCM) GPIO.setup(17, GPIO.OUT) GPIO.output(17, GPIO.LOW) time.sleep(0.25)
The script touch.py is started automatically when booting the rpi. I tried to debug it. But if it's running in the background and only failing after a while, it's difficult to find my problem. Some support would be highly appreciated.