I gave a talk at Bike Hack Night a couple of weeks ago, and have finally managed to put the audio and slides online. It runs about 12 minutes long and describes how I used the ESP8266 wifi microcontroller, ultrasonic rangefinding sensors, a homegrown iOS app and some data analysis to examine how much space cars afford me when passing me as I ride my bike.
It was a fun project! The big takeaway for me was the accessibility of these tools, both in terms of learning the technology and in terms of price. If you assume a smartphone is already handy, total bill of materials doesn’t even hit the $20 mark.
You can find the slides and audio here: http://sbma44.s3-website-us-east-1.amazonaws.com/bike-hack-night/index.html.