ANT+ Broadcast Interval Question

[DXCanas]

ANT+ Broadcasting is one of the biggest reasons I was so excited about this project. So thanks a ton for this y'all

openrowingmonitor/app/peripherals/ant/FEPeripheral.js

Lines 23 to 24 in 940489d

	const broadcastPeriod = 8192 // 8192/32768 ~4hz
	const broadcastInterval = broadcastPeriod / 32768 * 1000 // millisecond

Is there a particular reason we went with this broadcast interval? intervals.icu reports in the UI that the updates aren't happening at 1 value per second, which makes sense here — Would cranking this up be too resource intensive? Or is the 4hz an ANT+ FE standard thing?

[JaapvanEkris]

It is a standard ANT+ thing. We follow the spec here.

Please note that in the Garmin world position reports are indeed normally recorded once per second, but that crossing splits and intervals aren't. And the fit-specification explicitly allows for a trigger-based recording (like we do for our fit-file, which records on stroke completion, as then all metrics are updated and final).

[Abasz]

4hz is 4 times per second. what do you mean cranking up?

this means and this is what the ant specification requirers that we send one pocket four times a second but the pocket order and how often you need to broadcast one pocket type is strictly set. this means that there are pockets there are only send for instance only every 4 second like battery information.

but the most important general data that changes often are sent more than once per second (twice to be precise) : https://github.com/JaapvanEkris/openrowingmonitor/blob/main/app/peripherals/ant/FEPeripheral.js

[DXCanas]

That makes sense. But the icu interface complained about it being less frequent than one per second. I assumed this was happening on the ORM side but it seems it might be the watch 😊

[JaapvanEkris]

That makes sense. But the icu interface complained about it being less frequent than one per second. I assumed this was happening on the ORM side but it seems it might be the watch 😊

When a direct upload tin Intervals.icu is enabled, this indeed is the case. It is deliberate as in rowing metrics (aside time and distance) do not change in between strokes (this is because we present all metrics averaged across the stroke, instead of instantanuous, as pace/watts/velocity/strokerate/etc.. all vary a lot within the stroke). So reporting per stroke also allows decent counting of them, etc..