pi-dinger

This project allows ringing a bell with varying sequences from a Raspberry Pi using a solenoid. A Hubot plugin is provided so that you can ring the bell from inside a chat room. The Hubot plugin uses Amazon SQS so that your Raspberry Pi can live behind a NAT without any networking changes.

Hardware requirements

• Bell
• A solenoid such as https://www.sparkfun.com/products/11015.
• A transistor or relay so that the solenoid runs on a separate power supply from the Raspberry Pi. Warning: Hooking the solenoid directly to your GPIO pins can damaged your Pi.
• The solenoid will need to be mounted next to the bell. For the time being, this is done using cardboard and zip ties. 3D-printed mount coming soon from @nyxcharon.

Software installation on the Raspberry Pi

This was tested on the latest Raspbian based on Debian Jessie:

• Install AWS CLI: sudo apt-get install awscli.
• Add the user that this will run as to the gpio group: sudo usermod -a -G gpio USERNAME.
• Edit the paths and credential environment variables in the systemd service file raspberry-pi/bell-dinger-sqs.service.
• Install systemd service:
  • sudo cp raspberry-pi/bell-dinger-sqs.service /etc/systemd/system/
  • sudo systemctl daemon-reload
  • sudo systemctl start bell-dinger-sqs.service
  • sudo systemctl enable bell-dinger-sqs.service

Slack / Hubot integration

There is a Hubot script provided under hubot/ding.coffe. You can use the hubot-slack adapter to integrate with your Slack account. If you need a host you can use Heroku.

You will need to provide some envrionment variables to your hubot to access your AWS SQS:

export HUBOT_ACCESS_KEY_ID=YOUR_ACCESS_KEY_ID
export HUBOT_SECRET_ACCESS_KEY=YOUR_SECRET_ACCESS_KEY_ID
export HUBOT_AWS_REGION=YOUR_REGION
export HUBOT_AWS_SQS_URL=YOUR_SQS_URL

Once you have installed the ding.coffee script for hubot you will be able to ring the bell by messaging your hubot ding.

Example log

Alexander Paz [10:28 PM] 
@hubot: ding

hubot [10:28 PM] 
:bellhop_bell:

You can also specify a parameter that will be a sequence of dings.

@hubot ding 
@hubot ding 1001

The number determines the position of the solenoid. The example shown will strike the bell for 1/10th of a second, wait 2/10ths of a second, and strike the bell again for 1/10th of a second. The code only allows 20 numbers inside a single message.

Team Members

• Brian Masney
• Alex Paz - Hubot / Slack integration
• Bobby Martin - 3D printed mount coming soon

Images