Establish Bluetooth connection in least amount of time

RE: Establish Bluetooth connection in least amount of time

Andy — Fri, 17 May 2019 12:42:08 GMT

How low do you want to bring it? What's your target? Why isn't 35 ms fast enough?

RE: Establish Bluetooth connection in least amount of time

Benjameen — Fri, 17 May 2019 12:35:15 GMT

My peripheral has an advertising interval of 20ms and my central has as scan window of 50ms and scan interval of 50ms. Pushing these values any more seems to cause hard fault errors. I'm still getting around 35ms connection times.

Any other ideas? Or another method possibly?

RE: Establish Bluetooth connection in least amount of time

Sigurd — Thu, 16 May 2019 11:30:11 GMT

There is a trade-off between power consumption and the time it takes for the central to find your device and connect.

If you reduce the advertising interval (i.e. you send advertising packets more often), the central will be able to find and connect to your device faster, but the reduced advertising interval will also increase the power consumption. You might find the Online Power Profiler useful when evaluating what advertising interval you want to use.

Then on the central side you have the scan window and scan interval to tweak.

RE: Establish Bluetooth connection in least amount of time

Benjameen — Thu, 16 May 2019 09:36:14 GMT

That makes sense.

I do have control of the central device. It has the S132 API v5.0. I did increase the scan window to 100ms in an attempt to increase the connection speed.

Ultimately, though, the central device will be a phone app which I imagine would be different.

RE: Establish Bluetooth connection in least amount of time

awneil — Thu, 16 May 2019 09:06:56 GMT

[quote userid="79764" url="~/f/nordic-q-a/47366/establish-bluetooth-connection-in-least-amount-of-time"]if no central bluetooth device is present[/quote]

There is no way for the peripheral to detect that - other than waiting for a Scan Request or connection request.

So it all depends on how quickly the Central gets to "see" your advertising and, then, how quickly the Central can start its connection process.

Do you have control of the Central ?