Garmin

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Badger Jan 2023 11:38am, 26 Jan 2023 15,958 posts	0 Badger I found some documents saying that precise R-R timing for HRV needs a digitisation rate around 1kHz minimum - a bit lower might still work for showing the shape accurately. I would think the data would compress non-lossily nicely as the waveform is pretty simple compared to audio.
Steve NordRunner Jan 2023 11:52am, 26 Jan 2023 2,604 posts	0 Steve NordRunner I forgot the HRV bit. I've no idea what's in an HRM-Pro but I suppose there is easily some kind of signal-processing chip, considering an ipad is more powerful than a Cray 2.
chunkywizard Jan 2023 1:58pm, 26 Jan 2023 15,769 posts	0 chunkywizard I bet its an M33 approx 100MHz. I haven't seen a teardown but it's BT/ANT+ and modern MCUs with that spec tend to be M33 based.
Bowman 🇸🇪 Jan 2023 2:02pm, 26 Jan 2023 2,295 posts	0 Bowman 🇸🇪 And what does all this mean? There's not enough or the right "capacity", most likely, in the HRM straps?
Badger Jan 2023 6:11pm, 26 Jan 2023 15,959 posts	0 Badger Too many unknowns, not least whether the firmware has enough room for the extra code that would be needed, and how hard it would be to implement that. I think this is a fair representation of what people have said: We have no idea how the strap decides the R-wave position; it could be digitising the voltage it sees continuously and processing that for peaks, it could be an analog circuit that locates it and kicks the main chip every time it sees one, which would rule out this whole idea with current hardware. We think it's highly likely that the unit is capable of digitising the whole waveform standing on its head, in terms of processing and analog-to-digital conversion rates, but we don't know if it sees it, and obviously it isn't currently programmed to hold and transmit that waveform. A lot of current units can store hours of HR data (as heart rates once per second plus R wave intervals, so not much data per beat) and forward it to the watch later, so it wouldn't be a problem scanning the ECG for half a minute or so then forwarding that to the watch, maybe compressing it so it's reasonably quick even with the slow data rates of ANT.
Bowman 🇸🇪 Jan 2023 6:13pm, 26 Jan 2023 2,296 posts	0 Bowman 🇸🇪 Cool thanks !
Badger Jan 2023 11:45pm, 26 Jan 2023 15,961 posts	0 Badger Interesting. The Polar H10 sends ECG over Bluetooth at 130Hz (no other chest strap does AFAIK) github.com Sample rate might be a bit lower than ideal muscleoxygentraining.com But people have got clinically useful information from it e-coretvasa.cz
fetcheveryone Feb 2023 1:16pm, 1 Feb 2023 28,694 posts	0 fetcheveryone It looks like the server that sends us FIT files from Garmin is having a senior moment. 160+ files in the queue at the moment - but FE will keep trying until it recovers. I'll post again when there's news. Showing multiple reports of errors here: downdetector.co.uk
Big_G Feb 2023 1:19pm, 1 Feb 2023 2,261 posts	0 Big_G Yeah, it’s not working for me, and my data hasn’t been pushed to other places either.
Groundhog Feb 2023 1:27pm, 1 Feb 2023 5,284 posts	0 Groundhog My lunchtime walk got uploaded to Garmin and pushed through to Strava. Maybe still in the queue for Fetch?