Apple Bluetooth Design Guidelines

[Rodrigo Lorenzo Leal]

Hi Nordic Forum!

Looking for the right configuration for the connection parameters, found different references to this Apple guide. The problem is that in the 3rd condition it say:

Interval Min + 20 ms ≤ Interval Max Slave Latency ≤ 4

That condition has different outcomes depending on the interpretation of Interval Max Slave Latency. For example, this same question was asked before, but the answer was that:

Interval Max Slave Latency = Interval max * ( Slave Latency + 1 )

witch doesn't make much sense because the first condition states that

Interval max * ( Slave Latency + 1 ) ≤ 2

Additionally, in other answers given in the forum (like this and this), the following interpretation is taken:

Interval Max * (Slave Latency + 1) ≤ 2 seconds
Interval Min ≥ 20 ms
Interval Min + 20 ms ≤ Interval Max
Slave Latency ≤ 4
connSupervisionTimeout ≤ 6 seconds
Interval Max * (Slave Latency + 1) * 3 < connSupervisionTimeout

So my question in particular is: what is the correct interpretation? and, what rules should i follow?

Thanks beforehand.

[Sigurd]

The last interpretation is correct. There is nothing that’s called “Interval Max Slave Latency”. It's just a typo in the pdf document from Apple, where they forgot to add a new line. So the 3rd condition is really

Interval Min + 20 ms ≤ Interval Max
Slave Latency ≤ 4

If you take a look at this Apple Guides and Sample Code webpage, you can see that the typo is not there, and the last interpretation is listed.