How to add a custom characteristic to a standard BLE service?

[Ros]

Hi,

Is it possible to add a custom characteristic to a standard BLE service? I wish to add a CO monitor with ESS (0x181A). If yes, how to add a 128 bit UUID with this service? As per the tutorial provided in the link (https://github.com/NordicPlayground/nRF5x-custom-ble-service-tutorial) the characteristic uses a 16 bit UUID (with a 128 bit base) and the function "custom_value_char_add()" adding only this 16 bit UUID, but I think I have to add 128 bit here since the standard service UUID has only 16 bit in length.

[Vidar Berg]

Hi,

It is possible to add a characteristic with a 128 bit vendor UUID base to a 16 bit UUID service. To do this, you first need to add your custom uuid base through sd_ble_uuid_vs_add(), then reference this UUID base when adding your custom characteristic.

And remember that you need to increment the NRF_SDH_BLE_VS_UUID_COUNT setting in sdk_config adding whenever you add a new 128 bit base UUID. sd_ble_uuid_vs_add() will return a no memory error if you forget this.