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sensornetwork

The proposal is to replace wall-e with a distributed network of sensor and output devices.

  • in/out switch with LCD message
  • RFID swipe
  • temperature
  • light levels
  • PIR proximity sensor
  • IR remote control gateway
  • 13A socket switches
  • speaker
  • Club Mate counter
  • Fridge door sensor (could this be implemented as an internal fridge light level? :-))
  • Web-based dashboards
  • RRD-style graphs
  • laser cutter sensors: on/off, water in/out temperatures
  • LAN data: devices active, Internet bandwidth usage

Sensors can be connected using wifi, ethernet or radio modules (XBee or RFM12B). Tim favours the Jeenode architecture, using ATmega328P or ATtiny84 with the low-cost RFM12B radio modules.

Tim proposes the use of an AMQP or Redis messaging bus to handle all the sensor data. This would allow other Hacklab users to integrate their own sensors easily, and enable anyone to write scripts to consume the data created by the lab.

Aaron would like to discover more about the RFID cards used to access the building - can we use them to accurately identify users even without decrypting the content. Are they mifare? I have an ACR122U reader/writer en route and will research further. Proof of concept was successful.

  • Summerhall's access system appears to be from Paxton and not MIFARE compatible. ACR122U is unlikely to read the cards, but a cheap ID-2 or ID-20 might. – Tim (following discussions with Aaron in IRC)
  • The Paxton cards may be non-standard and ID-12 doesn't read them. The next approach is to use the ACR122U with NFC stickers, as a parallel system. – Tim, 2013-02-14

A Raspberry Pi could be used to host the messaging bus, and to mediate between RFM12B and TCP/IP protocols. Aaron has one that can be used to prototype.

Aaron built a housing for a new in/out switch, and the prototype build is in the lab but needs work.

Status

An AMQP server (RabbitMQ) is running on amqp.hacklab (one of the virtual machines).

timpi (Raspberry Pi in G1) is running a script to play sounds and speech.

doorpi (Raspberry Pi in G1 Door switch) - see below.

Publisher scripts:

  • ip/mac sightings from the LAN (timpi)
  • open/closed switch (wall-e)
  • PIR sensor (wall-e)

Subscriber scripts:

  • sound sample player (timpi)
  • speech player (timpi)

Code has been uploaded to https://github.com/edinburghhacklab/hacksense and local copies cloned to /srv/hacksense (on whichever servers are used).

Doorbot

Aaron's new in/out switch is now operational. It houses two buttons, a two-line LCD, a 13MHz RFID reader and a Raspberry Pi (“doorpi”).

  • /srv/hacksense/services/doorpi/buttons - reads the buttons via GPIO and generates events:
    • doorbot.buttons.{red,green}.{up,down,shortpress,longpress}
  • /srv/hacksense/services/doorpi/lcd - listens for events and updates the LCD:
    • doorbot.lcd.display - {“line1”: “Hello”, “line2”: “World”}
    • Optionally, add “delay” field to wait a number of seconds before continuing
    • Optionally, add “flash” field to display the message for a number of seconds before restoring the previous display.

Todo:

  • Move the PIR sensor to Doorbot and add it to the buttons script.
  • Move the speaker to Doorbot and copy the existing scripts from timpi.
  • Implement the RFID card reader

Interested parties: Aaron, Tim, Rob

sensornetwork.txt · Last modified: 2015-10-05 15:55 (external edit)