A Raspberry Pi, an echo sensor, a camera, a couple of resistors and wifi connectivity is all you need to build your own PiDoorbell. Well, that and some Python code.
In April 2014, I was a TA and Instructor for a workshop on PiDoorbell at PyCon in Montreal. (A link each to the tutorial video and source code is at the bottom of the page.) The objective of the tutorial was to bring up the hardware kit provided to each participant to successfully sense an object, and click a picture or video.
Over 20 folks were at the workshop and the TAs were on their feet helping everyone. I instructed the class on network setup on Raspbian with different ways of connecting to the network and helped bring up network connectivity via internet sharing from the laptop, via direct ethernet connection and also wifi hot spot access. To tide over the spotty wifi access, I had set up our own access point router fed from intenet sharing from my Mac, which in turn was connected to PyCon's wifi access.
Here is the full team of TAs and Instructors:
PiDoorbell at PyCon 2014 was a huge success! The preparation for this workshop was intense in the weeks preceding the event and it was great fun watching it unfold and consumed eagerly by participants.
Workshop video: https://www.youtube.com/watch?v=i62piPQkUtA
Python source for the project: https://github.com/CodeChix-OpenSource/PiDoorbell
CodeChix post: http://www.codechix.org/2014/05/pycon-2014-pidoorbell-tutorial/
Rupa's blog post: http://rupadachere.blogspot.com/2014/06/recap-of-pycon-and-pidoorbell-tutorial.html
Lyz's blog post: http://princessleia.com/journal/?p=9314
