A Raspberry Pi device to share a message on a slack channel when a door is opened.
1) Slack & Webhooks
Create a slack team for prototyping purposes and your first slack App. You will need a incoming webhook url to send the POST request with your message to slack.
Resources
https://api.slack.com/tutorials/slack-apps-hello-world
Try out your incoming webhook in the terminal:
curl -X POST -H 'Content-type: application/json' --data '{"text":"Door :door: is open! :open_hands:"}' https://hooks.slack.com/services/YOUR-SLACK-WEBHOOK
2) Raspberry Pi and PIR (passive infrared) motion sensor
Build your Raspberry Pi device. You will need:
- Raspberry Pi
- PIR sensor
- USB Wi-Fi adaptor
- Jumper wires (female to female)
Note: male to female will work too if you have a Breadboard
IMPORTANT: Setup
You will need access to the RPi via screen (HDMI), mouse and keyboard.
 |
 |
|---|---|
|
 |
Resources
https://www.hackster.io/hardikrathod/pir-motion-sensor-with-raspberry-pi-415c04
https://www.raspberrypi.org/learning/parent-detector/worksheet/
3) Download the sensor-butler repository in your RPi
In the Terminal:
$ cd Desktop
$ git clone https://github.com/nenoch/sensor-butler.git
Open pir.py and change the webhook url to the one in your slack app.
Resources
https://projects.raspberrypi.org/en/projects/getting-started-with-git
4) Schedule tasks with Cron
Follow the instruction in the cron-config.md file.
With this setting the sensor will be active at reboot and then everyday after midnight. Remember that the sensor will be 'triggerable' only once per day.
Note: remember change the path if your directory is not in the Desktop
Resources
https://www.raspberrypi.org/documentation/linux/usage/cron.md