Raspberry Pi Python script to email, tweet, or send an SMS if a garage door is left open.

Here is a heavily condensed quick start guide. New users are strongly encouraged to read the full documentation at http://www.richlynch.com/code/pi_garage_alert.

1. Equipment required
2. Raspberry Pi model A or B 1. 2GB or larger SD card for the RPi filesystem 1. Magnetic sensor (e.g. http://www.smarthome.com/7455/Seco-Larm-SM-226L-Garage-Door-Contacts-for-Closed-Circuits/p.aspx) 1. USB wifi adapter (if not using Ethernet) 1. USB power supply for RPi
3. Connect one wire of the magnetic sensor to a GPIO pin on the RPi and the other to a ground pin on the RPi. It is a good idea to put a 1kohm resistor in series with the sensor to protect the RPi from damage if anything is misconfigured.
4. Raspberry Pi initial setup
   1. Follow the guide at http://elinux.org/RPi_Easy_SD_Card_Setup to write the Raspbian image to the SD card.
   2. Boot the RPi and at raspi-config, expand the filesystem, set the "pi" account password, set the hostname, and enable SSH.
   3. Reboot the Raspberry Pi
5. Edit /etc/wpa_supplicant/wpa_supplicant.conf and configure the RPi to connect to your wifi network.
6. Regenerate the ssh keys for security.
7. Update the packages with sudo apt-get update && sudo apt-get upgrade, then install the dependencies:
   sudo apt-get install python-setuptools python-dev libffi-dev
   sudo easy_install pip
   sudo pip install sleekxmpp
   sudo pip install tweepy
   sudo pip install twilio
   sudo pip install requests
   sudo pip install requests[security]
   
8. Optional email configuration
   1. Configure postfix to send mail using Google SMTP, or your ISP's SMTP server
9. Optional twitter configuration
   1. On https://dev.twitter.com/apps/new, create a new application
10. Optional twillio (SMS) configuration
    1. Sign up for a Twilio account at http://www.twilio.com.
11. Copy bin/pi_garage_alert.py to /usr/local/sbin
12. Copy etc/pi_garage_alert_config.py to /usr/local/etc. Edit this file and specify the garage doors you have and alerts you'd like.
13. Copy init.d/pi_garage_alert to /etc/init.d
14. Configure and start the service with
    sudo update-rc.d pi_garage_alert defaults
    sudo service pi_garage_alert start
    
15. At this point, the Pi Garage Alert software should be running. You can view its log in /var/log/pi_garage_alert.log

The script will work with any sensor that can act like a switch. Some alternate uses include:

• Basement or washing machine leak sensors
• Window sensors