gap_conn_cfg vs role_count_cfg

[Neo]

I would like to use twenty concurrent connections. As I understand I should set ble_cfg.gap_cfg.role_count_cfg.periph_role_count = 20 and ble_cfg.conn_cfg.params.gap_conn_cfg.conn_count = 20. What is the difference between these two parameters? What happens if I put different values in these two configuration options?

My environment: S132 v4.0.2, SDK v13.0.0.

[Joakim Jakobsen]

Hi Neo!

ble_cfg.gap_cfg.role_count_cfg.periph_role_count = 20;

Defines maximum number of connections concurrently acting as peripherals.

ble_cfg.conn_cfg.params.gap_conn_cfg.conn_count = 20;  

Defines the number of concurrent connections the application can create with this configuration.

Regards
Joakim

[Neo]

Hello Joakim,

Does this mean that conn_count always equals to periph_role_count + central_role_count? Why do I need to specify conn_count explicitly?

[Joakim Jakobsen]

The default value of the conn_count is 1, so you would have to provide a new value to be able to have more than one concurrent connection. And it only makes sense to use periph_role_count + central_role_count, as that is the number of concurrent connections you want. You can take a look at how it is done in the multilink example, where there is defined two variables for the number of peripheral/central connections:

#define CENTRAL_LINK_COUNT         8
#define PERIPHERAL_LINK_COUNT    0

This is later used to set the values for the number of connections:

ble_cfg.gap_cfg.role_count_cfg.periph_role_count  = PERIPHERAL_LINK_COUNT;
ble_cfg.gap_cfg.role_count_cfg.central_role_count = CENTRAL_LINK_COUNT;
ble_cfg.conn_cfg.params.gap_conn_cfg.conn_count     = PERIPHERAL_LINK_COUNT + CENTRAL_LINK_COUNT;

[Neo]

Thank you!