HRM monitoring

Posted on Mon 20th, February 2023

• #1

Riccardokhm
Hi guys,
do you know if the value reported by the event 'hrm-raw' and in particular the ones in the Uint8Array
vcRaw are referred to BPMs or something else? Is there any kind of documentation anywhere?
Here attached a screenshot of the data printed to the console.

1 Attachment
• #2

fanoush in reply to @Riccardokhm

Is there any kind of documentation anywhere?

not sure there is anything better but the hrm source is here
https://github.com/espruino/Espruino/tree/master/libs/misc

for VC31 that structure is filled here https://github.com/espruino/Espruino/blob/master/libs/misc/hrm_vc31.c#L832
• #3

Gordon

As @fanoush says really - there's not much in the way of docs and unfortunately the heart rate monitor has had to be reverse engineered.

HRM-raw events are produced for every reading from the PPG sensor, so they are in general not related to BPM, but to the actual light sensor values from the sensor at that point.
• #4

Riccardokhm

Thanks guys for your continous support! I will go through the script you posted!

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