How to change GAP event length options in sdk_cofig.h?

[DL_November]

I'm using SEGGER Embedded Studio with nRF5 SDK v16.0.0.

For the purpose of high-speed data transfer, I've searched about the BLE throughput.

Now, I want to figure out how the parameters like MTU size and GAP event length affect my application.

I found the variable NRF_SDH_BLE_GAP_EVENT_LENGTH from the sdk_config.h file and want to change it.

However, if I increase the GAP event length according to the increased connection interval, the code fails to the NRF_BREAKPOINT_COND.

This does not happen if I decrease GAP event length, let's say 6 -> 3.

The only thing I tried is just changing text in header file.

Is there any specific method I have to follow to change sdk_config.h?

[Simonr]

Hi

What are you trying to increase the GAP event length to and what is the connection interval set to? Please keep in mind that you can't set the GAP event length to more than 100%. Please check out my colleague's bandwidth on BLE link connection blog post as well as this thread on GAP event lengths in DevZone.

Best regards,

Simon

[DL_November]

Thanks, Simonr!

I'm using MIN_CONN_INTERVAL = 7.5 ms, and MAX_CONN_INTERVAL = 15 ms.

Usually, the GAP event length is set to 6, which is the 100% case for 7.5 ms I guess.

So, to increase the GAP event length, should I set minimal connection interval more than 7.5 ms?

PS. According to the second link, does it mean that 100% GAP event length is 7 if I communicate with Android device?

[Simonr]

Correct, the GAP event length can not exceed the connection interval you're using. Regarding the Android question, this depends entirely on what the connection intervals are set to in your application and Android device. You can increase the GAP event length if the connection interval of both central and peripheral allows you to do so.

Best regards,

Simon