Heart rate monitor microbit project

Hi am wanting to make a heart rate monitor using the microbit. From reading different websites I believe that I need a heart rate monitor sensor to do this. Therefore I am wondering what could I use? I am also doing this on the ipad using the makecode website for coding.

Hi Sarah,

I would recommend using something like this Grove Ear clip:

and some alligator clip to male pins to easily connect it to the Microbit:

Here is an example sketch that should work to measure a heartbeat when button a is pressed. It kinda works as is by just putting your middle finger on P0 and pointer finger on GND.
https://makecode.microbit.org/_5H6W54dpW3h8