Pairing Latency and Current consumption in Advertising Mode

[DD_connectivity]

Hi,

We are in process of picking the right part from Nordic portfolio and are looking at nRF52 Series parts.

We are looking for best performance in below two aspects:

1) Pairing Latency.

2) Current Consumption during advertising.

Do guide us and share insights on below 2 queries.

a) How long does it take to pair and establish connection where one end will be using Nordic and other will be a mobile phone.

b) How much will be the current consumption during Advertising.

Do propose the best suitable Nordic part which excels in above mentioned aspect.

Thanks.

[Simonr]

Hi 

1. The pairing latency should be the same for all nRF52 devices, as they're using the same radio for BLE activity.

2. As for current consumption, the nRF52810 has the lowest total current consumption, with the nRF52832 close behind.

a) The connection interval will decide this factor. I believe Android phone has a minimum connection interval of 15ms, while iPhones need 30ms or so. The nRF52 devices are able to have connection intervals between 7.5ms and 4 seconds, so the limiting factor here is on the phone's side.

b) You can use our Online Power Profiler to see estimates of the current consumption for a variety of scenarios, including advertisements with various payloads and connection intervals, and connections for both central and peripheral.

So. If the device is just used as a peripheral that is going to connect to a phone, I would suggest using the nRF52810, but if you need more Flash and RAM space than it can offer, I'd suggest using the nRF52832.

Best regards,

Simon

[DD_connectivity]

Hi Simonr,

thanks for the inputs.

Can you guide me to any document where we can help me establish a standard pairing latency for nRF52 Device ( Say one nRF52 to another nRF52 device for simplicity) ?

Also, do you mean in case of phone, i cannot adjust connection interval at the phone end to be anything less than 15ms for Android ?

so best case scenario for a pairing between 2 nrf52 Devices is 7.5ms ? i think this is just the minimum transmitting interval there would be some overhead in terms of time for pairing also , WHAT WILL BE THE TOTAL TIME TAKEN TO PAIR 2 NRF52 DEVICES OR IF YOU CAN JUST GUIDE ON THE OVERHEAD then i guess i can make out the latency for phone as well ( Eg. 15ms + Overhead in ms = total pairing latency)

Look forward to your guidance.

Thanks

[Simonr]

Hi

This will vary between which kind of pairing method you are using. Seeing as there are quite a few ways to pair two devices, we don't have exact numbers on how long this takes I'm afraid. You can check out the peer manager library for more details on pairing.

In any case, the pairing process itself should not take very long and is estimated to be ~100ms + any extra time like connection intervals, entering passkeys, etc.

Best regards,

Simon