GPIO Switch not working

[Josvds]

I want to create a managed light switch in my garage.
I have one pipe where i have put the electricity cable and also a 2mm cable for the switch.
The switch is connected with to wires directly to the raspberry.

When i tested it on my desktop it worked file.
After conencting the switch in my garage the item returns the message 'Button Pressed' without stopping when switching...

What can i do?

See the attachment for how i connected it in test.
A drawing of how i connected it in the garage.

Code: Select all

import RPi.GPIO as GPIO
import time

GPIO.setmode(GPIO.BCM)

GPIO.setup(18, GPIO.IN, pull_up_down=GPIO.PUD_UP)

while True:
    input_state = GPIO.input(18)
    if input_state == False:
        print('Button Pressed')
        time.sleep(0.2)

[Moe]

Looks like it's dropping voltage. How long is the cable? Can you measure the voltage at the switch?

[Josvds]

Details from the project:
* The wire is about 10 meter near the 230v cable.
* The 230v cable is three wires of 2.5mm.
* The switch is connected by two 0.5mm wires.
* Both are in the same pipe
* Switch wire 1 is connected to pin 18, switch wire 2 is connected to GRND.

This is how i connected it in test.

The attachment Photo.jpg is no longer available

The attachment Photo.jpg is no longer available

[drgeoff]

The GPIO wires will be picking up a substantial AC voltage from the mains cable.

You can try adding an external pull up resistor, say 330 ohms, at the RPi.

[Josvds]

Ok, thanks i will try this tonight..

[Josvds]

I was able to fix it by using a 10k resistor.. But after a while the button flipped without using the switch..
I did change my connection to this https://www.raspberrypi.org/learning/ph ... l_up_down/

3v > switch > (300 resistor > Pin 18) AND (10k resistor > Grnd)

Thanks for your help..

[drgeoff]

If the switch cable is a flat twin eg bell-wire, that is much more susceptible to pickup than a twisted pair.