Internally his heart rate monitor is using an Arduino Pro Mini, a small OLED screen, and a turn-key pulse sensor which was originally conceived as a Kickstarter in 2011 by “World Famous ...

He wanted to do a little more with the equipment so he ditched the watch and built an Arduino-based heart rate monitor. He’s still using the chest strap and was happy to find that SparkFun sells ...

The Geek Pub guide will help get you started with an Arduino pulse sensor. While sensors like this are reliable, it's worth keeping in mind that your heart rate can tell you a lot of different things.

If you would prefer to build your very own DIY heart rate monitor, rather than purchase an expensive smartwatch or fitness tracker. You may be interested in a project published to the Hackster.io ...

The Samsung Galaxy S5 phone comes with a built-in optical sensor to sense fingertip pulse and was accurate even at a heart rate of 190.