How often should I read accelerometer data?

Does the Ruuvi tag advertise momentary, individual and independent accelerometer readings?

Say I put it in a fridge door and want to detect when the fridge is opened. Given the advertising interval of 1s, the opening will last <1s and the closing too. If the readings are independent, it will mean that there will be only one packet that shows some acceleration for the opening, and another one with the opposite sign for the closing.

However, I’m concerned because BT advertisement is unreliable, losing a few packets is completely normal. So I can easily miss these events.

It might be a lot better if the Ruuvi summed up the movements over say 10 seconds, and then kept advertising this data for 10 seconds. It would send the measurements 10 times in equal packets so it would be unlikely to lose the information.

How does it exactly work and do you think my idea makes sense?

Hi,

FWIW, I have been using a version of the firmware that I modified to get real-time accelerometre data. It has worked flawlessly so far (almost a year) and I reliably detect my front door opening.

Cheers,
François

1 Like

I just noticed that the next firmware will have a movement counter, guaranteeing that movements will not be lost: Proposed next high-precision Data Format