Doorbell on GPIO script Topic is solved

[marmachine]

Hi Folks,

I've been working on a doorbell script, this should trigger when the specific GPIO pin goes low.

Code: Select all

#!/usr/bin/python

# Doorbell py with read contact uitlezen,
# GPIO 18 to Ground when button is pushed
# Release 1
# Author J. Jeurissen / M. van Wijngaarden
# Copyright (c) 2015  J. Jeurissen  / (c) 2017 M. van Wijngaarden
# Python 3

import urllib
#import urllib.request
import json
import RPi.GPIO as GPIO
import time

# Settings for the domoticz server
domoticzserver="192.168.2.100:8080"
domoticzusername = ""
domoticzpassword = ""

domoticzurl = 'http://'+domoticzserver+'/json.htm?type=command&param=switchlight&idx=189&switchcmd=On'

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')
                response = urllib.urlopen(domoticzurl)
                data = json.loads(response.read())
                print data
                time.sleep(5.0)

It seems to work when i start the script manually, however it won't start from CRONTAB.
Here's my crontab:

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pi@raspberrypi:~$ crontab -e

@reboot /usr/bin/python /home/pi/domoticz/scripts/python/doorbellgpio.py >/home/pi/domoticz/scripts/python/logs/cronlog 2>&1

EDIT: found the solution, using the following crontab entry, now works for me after reboot:

Code: Select all

@reboot /usr/bin/python /home/pi/domoticz/scripts/python/doorbellgpio.py

Here's how i start the script manually and the result when the doorbell (button pressed) rings.
Though, i have to say that i don't understand the line below "button pressed"... does that indicate an error?

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pi@raspberrypi:~$ python /home/pi/domoticz/scripts/python/doorbellgpio.py
Button Pressed
{u'status': u'ERROR', u'message': u'WRONG CODE', u'title': u'SwitchLight'}

As you can see i am no expert, but maybe you can help me figure out what's wrong here?
Thanks in advance.

Marco

[D'rMorris]

It seems that your Domoticz URL is not complete. If you look at the wiki, the syntax to switch a light / switch on is:

/json.htm?type=command&param=switchlight&idx=xxx&switchcmd=On

You only have:
/json.htm?type=command&param=switchligh$.
If you update your URL it should work.

[marmachine]

It seems that your Domoticz URL is not complete. If you look at the wiki, the syntax to switch a light / switch on is:

/json.htm?type=command&param=switchlight&idx=xxx&switchcmd=On

You only have:
/json.htm?type=command&param=switchligh$.
If you update your URL it should work.

Thanks for your reply!
Unfortunately that is not entirely correct, it actually appeared to be correct on my Pi so i guess this was a typo (error with copy-paste).
I've updated my original post (script).

The strange thing is that it works when i manually start the script.
So i wonder why it won't start on reboot.

[D'rMorris]

How do you run it when you run it manually? Do you start it with user pi (or any other user which is not root) logged in? As far as I know, but I might be wrong, is that GPIO needs root. Now, you run it as root when you reboot:

@reboot sudo /usr/bin/python /home/pi/domoticz/scripts/python/doorbellgpio.py >$

but perhaps you could try to add the line above in the crontab for user root? first do a su root when logged in as user pi and then crontab -e and add the line above. That way, you can at least check if it's a authorization issue or not.

[marmachine]

How do you run it when you run it manually? Do you start it with user pi (or any other user which is not root) logged in? As far as I know, but I might be wrong, is that GPIO needs root. Now, you run it as root when you reboot:

@reboot sudo /usr/bin/python /home/pi/domoticz/scripts/python/doorbellgpio.py >$

but perhaps you could try to add the line above in the crontab for user root? first do a su root when logged in as user pi and then crontab -e and add the line above. That way, you can at least check if it's a authorization issue or not.

I run it manually, logged in as 'pi', issuing the following command:
python /home/pi/domoticz/scripts/python/doorbellgpio.py

This results in a triggered virtual switch which is representing the doorbell. So i assume it should work, even without root.
So, i just figured maybe try an entry without logging, so i've altered my crontab entry to the below (still logged in as 'pi'):

@reboot /usr/bin/python /home/pi/domoticz/scripts/python/doorbellgpio.py

Guess what, after reboot, the above is working!
For some reason the previous crontab entry wasn't correct!? Well, i don't care for logging in this particular case, so i'm happy!

Thanks all!

[D'rMorris]

I don't know logging with >$. In my own cron I use >/dev/null 2>&1. Does the same as using no logging I guess, because the log is directed to /dev/null.

[marmachine]

I don't know logging with >$. In my own cron I use >/dev/null 2>&1. Does the same as using no logging I guess, because the log is directed to /dev/null.

Some part of my original code was lost there somehow... below is my original entry (which doesn't work!):
@reboot /usr/bin/python /home/pi/domoticz/scripts/python/doorbellgpio.py >/home/pi/domoticz/scripts/python/logs/cronlog 2>&1