Occupancy Sensor


[edit] HacDC Lab Occupancy Sensor

HacDC's lab occupancy sensor is now operational.

Key features include:

  1. Real-time and historical occupancy data is available for your projects. Perhaps a twitter bot, data visualization heat map or remote occupancy indicator?
  2. The underlying architecture demonstrates an approach allowing bidirectional communications between many microcontrollers and many application
  3. The Google Calendar "hacdcdoorman@gmail.com" is updated every five minutes with current occupancy data

[edit] Technical Overview

The current system is a WRT54G with the described hardware below attached to GPIO on the CPU of the router instead of on a PC. Normal functionality was supposed to be done over wireless, however due to AP changes this has not been updated on the device side for altered SSIDs. Currently, to ensure functionality, the WAN port of the router must be plugged in via wired network for operation. Currently, this is a Cisco FastHub 108T due to the failure of the existing switch (In process of being re-capped/repaired, there were 4 bulged capacitors). This is also where the payhone ATA is currently connected to the network as well.

The information below is out of date ----

Martin configured a sensor system consisting of an Arduino, a Radioshack photoresistor (276-1657) and a Quest passive infrared motion detector as shown in the following schematic diagram.


This Arduino is connected to the jukebox computer via USB and monitored by a simple Python script that forwards occupancy sensor data to a Spread messaging system (see spread.org). Several "agent" applications receive occupancy status messages via Spread and perform tasks such as updating a Google Calendar and data logging.

All software developed as part of this project is GPLed and available via LaunchPad at: https://launchpad.net/hacdcoccupancy

A demonstration agent is also included in the distribution, providing a convenient starting point for your projects. This demo agent currently toggles LEDs in my house based on HacDC lab occupancy status.

[edit] HacDC Doorman Google Calendar


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