Bypass slave latency locally?

[TBone]

This is referring to running a peripheral device on the PCA10028 eval board.

Let's say I have a connection interval of 100 ms, and a slave latency of 5.

So the BT stack only wakes up every 500 ms to interact with every 5th connection event.

Is it possible to force a wake up and to listen to all connection events WITHOUT renegotiating with the master for new connection parameters? (Slave Latency in particular.) I know I can send data out on each connection interval, but can I force the SoftDevice to 'listen' on each interval without going through a renegotiation with the master?

Thanks for any info.

[Ulrich Myhre]

Hi!

No, this is not possible, short of sending something the connection intervals you want to be awake.

What is the use-case for this though? If the central wants to send burst data, but seldom, it could simply change the connection parameters back and forth when this is needed (without any negotiation). Changing the connection parameters will take at least 6 connection intervals, so you need to do this slightly in advance.

[TBone]

Thanks for the reply. The situation is a peripheral on coin battery that must last months, but must report event data vey quickly. So we have a connection interval of 10 ms, and a slave latency of 100. So the peripheral only needs to fire up its radio every second. But when bonding, this process can take many seconds since the peripheral only gets each discovery message every second. If our bonding process can be triggered by a button press, then I'll have the peripheral request a 0 slave latency during the pre-bonded connection, and then after bonding it can request a big slave latency.

[Thomas]

Hi, is this still not possible (SoftDevice s110)? Our use-case is that we only want to utilize the slave latency during our timeslot, outside of that we need a low response time and throughput both ways.

[Ulrich Myhre]

That is sort of the opposite problem. What you can do is to use a slave latency of e.g. 1 combined with a very long supervision timeout, then adjust the local connection latency to a longer one. See ble_gap_opt_local_conn_latency_t in the GAP module. It is set through the options API.

[Thomas]

Thanks for the quick response, I made a mistake in my comment, I meant a "low response time". So I could use a low connection interval with a low slave latency and a high supervision timeout to get a high throughput and use ble_gap_opt_local_conn_latency_t before requesting a timeslot to create a timeslot longer than the original connection parameters allowed?