Instructable for Raspberry Pi e-mail push button device
by Peter and Owen Czerny at Yukonstruct
Don’t have access to a commercial mobile e-mail communication device or laptop / desktop computer? Need an inexpensive way to e-mail a routine message to someone on a regular basis?
The goal of this project: To use a Raspberry Pi to send a preset message to a predetermined e-mail address via Gmail with the push of a button.
What we set out to learn through this project: 1. connecting a button to a Raspberry Pi, 2. learn some programming in Python, 3. connecting the Raspberry Pi to the Internet and communicating with an e-mail server.
Raspberry Pi 2 Model B with access to a screen and keyboard (via USB cables)
tactile button switch, see: https://www.adafruit.com/products/367
2 Male to Female jumper wires, see: https://www.adafruit.com/products/367
USB drive for storage
Also: know your existing Gmail address and password as well as the address you want to send your message to. Note: you need to allow your Gmail account to let less secure apps log on. See your settings under 'Connected apps&sites / Allow less secure apps (switch to 'ON')' at: https://myaccount.google.com/security?pli=1#connec...
Source for code: www.razzpisamples.oreilly.com/ch07.html
Step 1: Wire Button to Raspberry Pi
Connect switch to a power pin and a GPIO pin - we used pin 1 (3.3 VDC power) and pin 16 (GPIO4)- see photo and example at http://razzpisampler.oreilly.com/ch07.html - see pin layout diagram at http://razzpisampler.oreilly.com/ch07.html
Step 2: Enter the Code
Boot up Raspberry Pi and login (default username: pi and password: raspberry)
Type ‘NANO /tmp/button_test.py’
Enter code (see first program in the attachment).
Note: ensure that you keep the tabs in the sample code as the Python language needs them to run the program.
Note: ensure you put in the code - in the spaces indicated - i) your message to send, ii) your Gmail address and password, and iii) the address where you want the e-mail message to be sent to.
Press 'control-o' to save [in tmp subdirectory, e.g. /tmp/button_test.py]
Press 'control-x' to exit text editor
Step 3: Run the Program ... Send the E-mail!
To run program, type ‘sudo python /tmp/button_test.py’ - and press the button to send the preset message!
Press 'control-c' to exit program run mode.
If nothing happens, check to make sure that the wires are connecting the right pins to the button. See the second program in the attachment in Step 2 for suggested code to test the button.
Note: Gmail will stop the Raspberry Pi from sending too many of the same message.
Ideas for improvements to evolve this Raspberry Pi device:
Include a time-out cycle in the program code to avoid sending repeated e-mails when button is pushed.
Combine preset text phrases into a message to send to a preset e-mail with the push of several buttons.
Create a case for a more handy device with labeled buttons.
Autorun the program after the Raspberry Pi boots or reboots.