Significant difference in connection time with different adv intervals

[nordicdev]

Hi,

I have the following set up:

The remote: nrf51822 acts as central

The wheels: Each wheel has nrf51822 acting as peripheral.

The remote needs to first connect(at time: T1), then bond with both the wheels, exchange some handshake information regarding wheel status with both wheels, then proceed to active mode at time: T2(where both wheels are controlled by the remote).Connection interval is : 7.5msec to 30msec.

Case 1: When both wheels have advertisement interval as: 50msec, T2-T1 is less than a second.

Case 2: When both wheels have advertisement interval as: 200msec, T2-T1 is approximately 3 seconds.

Why is the huge time difference (more than a second) in case 1 and 2? Is this an expected behaviour?

Thanks.

[run_ar]

Most likely it is expected behavior. But could you also tell us what you scan interval and window is? that could help understanding this. Rememer that the time it takes to establish a connection depends on both the advertiser and the scanner settings.