Multilink Peripheral BLE Services

Question

Hello, 
 for multilink client services Nordic introduced the *_EVT_DISCOVERY_COMPLETE events and the *_c_handles_assign functions. Like the BLE_BAS_C_EVT_DISCOVERY_COMPLETE event and the ble_bas_c_handles_assign function for the Batterie Client Service 
 What is the procedure for multilink server services like the Batterie Server Service? How can I instantiate this service multiple times i.e. one for each possible connection? At the moment the service captures the connection handle 
 static void on_connect(ble_bas_t * p_bas, ble_evt_t const * p_ble_evt)
{
 p_bas->conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
}
 
 So that even when I instantiate the service several times, they all capture the last connection handle. This has the consequence, that when I call ble_bas_battery_level_update only the last connected device received the notification. I have no choice to select a specific device. 
 For the LED Button Service Server Nordic the "button change" function has an explicit conn_handle argument to select the client. 
 uint32_t ble_lbs_on_button_change(uint16_t conn_handle, ble_lbs_t * p_lbs, uint8_t button_state);
 
 How can I use the Nordic server services like the Batterie Service with multiple clients?

Petter Myhre · Accepted Answer

The battery service module doesn't really support multiple instances, so the library has to be modified. The first step would be to add something like this: 
 /** @brief Macro for defining multiple ble_bas instances.
 *
 * @param _name Name of the array of instances.
 * @param _cnt Number of instances to define.
 */
#define BLE_BAS_ARRAY_DEF(_name, _cnt) \
static ble_bas_t _name[_cnt]; \
NRF_SDH_BLE_OBSERVERS(_name ## _obs, \
 BLE_BAS_BLE_OBSERVER_PRIO, \
 ble_bas_on_ble_evt, &_name, _cnt)
 
 And declare the number of instances you want. I haven't look further into the library to see what other changes are necessary. Let me know if you get into trouble.