Space state

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Revision as of 12:07, 20 November 2021 by Xopr (talk | contribs) (migration to MQTT)
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Project: Space state
Featured: No
State Completed
Members Vicarious, xopr, Coolepascal, Prodigity
GitHub No GitHub project defined. Add your project here.
Description Show the current state (open or closed) of our space
Spacestate closed.jpg

Marked as outdated
The system-to-be-installed uses Tasmota firmware combined with an [MQTT] script

current implementation

See ESP8266-SpaceState and SpaceAPI. The space state is connected to fuse group A.

previous version


A php script now periodically runs on the server to check when the spacestate has last been set;
if it is has been longer then 5 minutes it sets the state to "?".
This has been done to prevent power outages and loss of internet connection leaving an incorrect state.


Vicarious and Prodigity have revived the SpaceState switch; It now uses a raspberry pi.

The raspberry pi is currently running a python daemon which reads a GPIO pin every 10 seconds. This GPIO pin is connected to one end of the switch and a ground connection from the GPIO header is connected to another. When the switch is in the 'off' position the GPIO pin gets pulled up to +3.3v with the help of a 10K resistor, otherwise (when the switch is 'on') the GPIO pin gets pulled down.

The python script uses the RPi.GPIO, urllib2 and time library to accomplish its task. RPi.GPIO is used to easily read the GPIO pins from within python. urllib2 is used to post the spacestate to the website. Time is used to limit the amount of GPIO polls and more importantly, to limit the amount of network traffic.


Click here to view the source code
import time, urllib2
import RPi.GPIO as GPIO
GPIO.setup(18, GPIO.IN)

# Check space switch for ever and ever ....
while 1:
        input_value = GPIO.input(18)
        if input_value == 1: # Space closed
                        bla = urllib2.urlopen('..')
                        print "Couldn't connect.."
        else:                # Space open
                        bla = urllib2.urlopen('..')
                        print "Couldn't connect.."
        print input_value # for debugging purposes..
        time.sleep(10) # Poll every 10 seconds..

first version

The SpaceState switch is working fine now. This is how it's done:


We found a huge power switch which we mounted to the space wall this switch is connected with a cable to the Space-Mac using an serial to usb converter. On the Mac a perl scripts reads the space state. If the space-state changes, the perlscripts uses wget to call an php script on the ACKspace website. The php scripts sets an space-state variable in a file. The same script is used to read the space-state variable and show the status on the webpage.


This is the perl script that does the thing on te Mac (note that this code is not yet the actual running version)

Click here to view the source code
   #!/usr/bin/perl -wT
   # Title    :
   # Function : read spacestate switch en set action accordingly
   # Author   : Pascal Schiks (C) 2011

   my $serialdev="/dev/tty.PL2303-000061FD";
   use strict;
   use IO::Handle;
   use Fcntl;

   my $TIOCMGET = 0x5415;

   my $spacestate=0;
   my $lastspacestate=$spacestate;
      if(sysopen(SERIAL, $serialdev, O_RDWR))
         my $mdmctl="";
         my $ioresult;
         unless(($ioresult=ioctl(SERIAL,  $TIOCMGET, $mdmctl))==-1)
            $mdmctl = unpack('i',$mdmctl);
            $spacestate = ($mdmctl&64)==0 ? "open":"close";
            print "$spacestate\n" if($spacestate ne $lastspacestate);
            print "Weet ik veel Error\n";
         $lastspacestate = $spacestate;
         print "Error, Could not open $serialdev\n";

Here to put the php script running on the webserver.

      some code

pics or it didn't happen

Location: hACKspace (between the two doors)