An Arduino Uno provides the processing power and drives the serial monitor. A joystick and a Hitachi H48C accelerometer are mounted on a breadboard and wired to the Uno.

A rolling average of five inputs are used to help smooth the display data, which is shown on the 2.8″ LCD screen seen above. Posted in Arduino Hacks Tagged chest strap , heartrate , monitor , polar ...

If you have allergies than you've likely considered picking up an air quality sensor for you house at some point. However, a good air quality monitor will run you upwards of $290.