NCS based multi role multi link device

[db_lw]

Hello,

I'm working with NCS on a nRF5240 based BLE device.

On the BLE side I want to do something like this:

• Connectable advertising
  
  • Phy: 1M
  • Interval: 200-500ms
  • Concurrent connections ~ 2
• Scanning
  • Phy: CODED
  • Filters service UUID
  • Concurrent connections ~ 20

The device advertises service A and scans for devices with service B. Advertising and scanning should only stop if the maximum number of connections are reached.

I'm not sure what's the best way to use NCS for this application. I couldn't find a suitable multi-role example project so I decided to use the nRF Desktop application sample as starting point. The problem is none of the configurations use both advertising and scanning.

Is there any NCS multi-role example?

Thanks in advance.

[Simon]

The Zephyr example Scan & Advertise demonstrates how to scan and advertise simultaneously. I can see the that the sample does not initiate any connections, please tell me if this sample is not suficcient and I will investigate more.

Best regards,

Simon

[db_lw]

Thank you for the answer.

This example doesn't really answer all my questions, actually the connection handling with the multi-role setup is the part where I struggle the most.

[Simon]

I assume this should work out of the box, just run the necessary functions to start scanning, connectable advertising, and to initiate the connections. I think the BLE stack should handle everything for you then.

If it doesn't work, please get back to me and I'll try to get it working myself.

Just remember to set the following:

CONFIG_BT_MAX_CONN=22

It does not seem like 22 connections are supported if you use the SoftDevice Controller (only tested with 20 connections). However, it seems like it's supported if you use the Zephyr BLE Controller, where you're able to select up to 64 connections. I can ask internally to get more clarification on this if you would like.

Best regards,

Simon

[db_lw]

Thanks for your help!

Additionally to your answers the Enter the Multi NUS a simple wireless UART network article from a Nordic colleague really helped.

Best regards