How can I control connection parameters

[Daliwan]

I use example ble_app_uart_pca10028_s130, I want to change the connection parameters by changing #define MIN_CONN_INTERVAL, #define MAX_CONN_INTERVAL, but when I use oscilloscope, I find it stick to a period of 50ms. Why?

[Daliwan]

I found it because the nrf toolbox for mobile fix it. After I use nrf connect, I can change a little. But how can I change the connect interval to 1 second on mobile? thanks!

[endnode]

Hi Daliwan,

Connection parameters are controlled by Master which is GAP Central device. Peripheral can only suggest some parameters through Preferred Peripheral Connection Parameters or by requesting parameter change through Peripheral Connection Parameter Update procedure. However the result always depends on GAP Central. If you are GAP Central but on some rich OS device with many layers of APIs (such as iOS or Android) then you need to check what your particular device and API version support. There seems to be some methods how to ask for lower interval but in general this used to be restricted area decided by handset manufacturers (or to be more specific their BLE chipset+low level stack supplier such as Broadcom and similar companies) and they don't allow top layer application developers to mess up with the parameters as they want...

Cheers Jan

[Turbo J]

What is the central? Apple IOS does not allow lower interval unless you implement HID profile.