Create trough detection for IR and Red buffer for DC value

[yukitfoo]

refer to library for inspiration.

We want to input a buffer for IR and red, using one of the buffers, get the peak value and obtain the DC value (trough value).

https://github.com/DKARDU/heartrateNbloodoxygen/blob/main/Pulse.cpp

[YznH1]

Trough detection applied