How to correctly set channel map of next connection?

RE: How to correctly set channel map of next connection?

Ole Bauck — Wed, 02 Dec 2015 13:09:33 GMT

An internal request have been made.

RE: How to correctly set channel map of next connection?

Ole Bauck — Tue, 01 Dec 2015 12:27:31 GMT

I will check this.

RE: How to correctly set channel map of next connection?

Gregor Bader — Tue, 01 Dec 2015 12:14:23 GMT

What are our options to get a softdevice which is able to set the channel map beginning with the CONNECTION REQUEST packet? Our communication cycle is not longer than 10 connection events!

RE: How to correctly set channel map of next connection?

Ole Bauck — Mon, 30 Nov 2015 14:28:58 GMT

When setting the channel map, it applies to all current and future connections, so you can set it whenever you want. The packet with the channel map will be sent to the peripheral 10 connection events after the connection request packet. This means that if you use a connection interval of 20ms, the channel map will not be updated before at least 200ms after the connection request packet. The reason for this is backwards compatibility with previous nordic devices.

RE: How to correctly set channel map of next connection?

Gregor Bader — Mon, 30 Nov 2015 09:55:21 GMT

It is important to know which event or when the channel map is updated. I'm working with very short connection durations (~200ms) and thought the channel map is used from beginning of connection.

RE: How to correctly set channel map of next connection?

Ole Bauck — Mon, 30 Nov 2015 09:51:44 GMT

I was just using the connection parameter update request event to read the channel map since I knew this happened 5 seconds after the connection. The channel map have been updated some time in between. Feel free to start a timer (e.g. app_timer) on connection and read the channel map sooner to see when it changes.

RE: How to correctly set channel map of next connection?

Gregor Bader — Mon, 30 Nov 2015 09:46:41 GMT

Regarding your test, is the channel map only updated with "connection parameter update request"???

RE: How to correctly set channel map of next connection?

Ole Bauck — Mon, 30 Nov 2015 09:32:38 GMT

I tested it before calling sd_ble_gap_connect(...) as in your question and it worked. I checked in the connection parameter update request event (5 seconds after connection) . For the time it takes to change the map, this is from the bluetooth spec: "If this command is used, updates should be sent within 10 seconds, of the Host knowing that the channel classification has changed. The interval between two successive commands sent shall be at least 1 second."

RE: How to correctly set channel map of next connection?

Gregor Bader — Mon, 30 Nov 2015 06:23:30 GMT

Your reference seems to only apply when changing the channel map during an active connection. But I want to change it before a connection.

And what is "some time" ? 1s or 1 minute?

RE: How to correctly set channel map of next connection?

Ole Bauck — Fri, 27 Nov 2015 13:09:27 GMT

Setting the channel map may take some time, see here. Try to call sd_ble_opt_get(...) at a later point in time.