How does the peripherals reconnect to central board when the BLE connection lost

[laumung]

Hello everyone, I am developing a system with multiple peripherals to a central board. How many peripherals can keep connecting with central at one time? I made some peripherals connected to a central board but after several hours, the connection of some peripherals lost and cannot reconnect to the BLE network. How can the peripherals reconnected to the central board? I have enlarge the timeout to 20s but it doesn't work. Any help will be appreciated. 

[Jared]

Hi,

Are the boards still advertising after the disconnection? The S130 should be able to support up 20 links simultaneously.

best regards

Jared 

[laumung]

Hi Jared, thanks for your information. The peripheral boards will not advertise after disconnection. I use S140 for nRF52840 and NUS (Nordic UART Service ) to transfer the data. I think 20 links will be great. Which function did you implement in the project? How to configure the parameter for the multi-link to the central, such as advertising interval? Thanks.

[Jared]

Hi,

How would the peripherals re-connect to the central if they never restart the advertising? 

See this section for suggested connection interval and window.

regards

Jared 

[laumung]

Hi Jared, thank you for your reply. I checked the post you mentioned. I also checked other sections related to it. My project is about multi peripherals to two central. The firmware of the peripherals is based on ble_app_uart. The peripherals have timers and send data periodically to the central. But they can't send data in a stable order like the figure shown in the document because the timer of the peripherals is running independently. 

When some peripherals did not set up links with the central, they will lose connection with the central. 

What should I do about that? Thanks.

[Jared]

Hi,

laumung said:

But they can't send data in a stable order like the figure shown in the document because the timer of the peripherals is running independently. 

Either way, they should only send during the connection interval?! Have you made sure that all of the connection have a common factor for their connection interval as explained in the documentation? What connection parameters are you using?

laumung said:

When some peripherals did not set up links with the central, they will lose connection with the central. 

So they stop advertising after a set time? Try restarting the advertising periodically after some time.

regards

Jared