Set Default Channel Map

[Roy Greenwood]

Can the 

sd_ble_opt_set

function be used to set a default channel map in the central role prior to any connection requests to advertising peripherals being made?

[Roy Greenwood]

Apparently an internal request was made about 3 years ago to provide a modified Soft Device to send the modified channel map to the peripheral at connection event rather than on or after the 10th connection event. For instances where devices are operating in close proximity to other ISM band devices it would be nice to be able to set the default channel map of the peripheral at the connection request to prevent any RF at the excluded channels from interfering with the devices utilizing the excluded channels. Perhaps this could be included in a future Soft Device release, in the mean time can you suggest any work around or provide a modified Soft Device?

My use case is 2 co-located nRF52840 radios one operating as a central role GAP/GATT supporting 20 connections and a second nRF52840 radio operating as a Thread Mesh Router. I cannot use the dynamic multi-protocol capabilities due to performance requirements and the use of a central role. The device is a Bridge device between the 20 GAP/GATT peripheral role devices and the Thread Mesh. The Thread Mesh is required to achieve extended range and more nodes.

[ovrebekk]

Hi 

I have sent a request to the SoftDevice team to ask about the current state of this feature. 

Have you tested this yourself to verify that the update doesn't happen until the 10th connection event?
What SoftDevice are you using?

Best regards
Torbjørn

[Roy Greenwood]

Hi Torbjorn,

I have not yet tested it, I was basing my questions on the earlier thread, I am expecting to utilize the latest Soft Device for the nRF52840 so that I believe would be from SDK v15.0.0 , Soft Device s140 v1.1

I have 22 nRF52840 development kits on order to do the testing.

I apologize for not knowing how to link to that thread but I pasted the contents here.

Offline Ole Bauck over 3 years ago in reply to Ole Bauck

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.

[ovrebekk]

Hi Roy

Just messaging you so you know the request is not forgotten ;)

Not much has happened over the summer, but I will follow up with the stack group from now and see if there is something to do about this. 

Best regards
Torbjørn