What is RR in the heart rate monitor example?

[tyler]

I am working through the nordic sdk 8.1 peripheral heart rate monitor example.  I am wondering what RR is?  I can't figure out what it stands for or what the purpose of it is.

[Håkon Alseth]

An EKG has a specific shape when looking at the signal, and has several components which are named with a single letter; P/Q/R/S/T.

The R-R interval points to the frequency of one of these named components. Please see this wiki article for more information:

https://en.wikipedia.org/wiki/Heart_rate#Electronic_measurement

Best regards,

Håkon

[tyler]

It look like the wikipedia page you posted just pertains to heart rate monitor programs.  Does that mean if I have just a battery service and not a heart rate service I don't have to worry about it?