Central can´t find primary services on Ti SensorTag

[Vehring]

Hello.

I use the BLE multilink central example to connect to 2 sensors. I changed the example in that way that i successfully connect and read data from a Wahoo Cadence Sensor (CSC profile). In addition to that i want to connect to a Ti SensorTag to read out the Gyro and Accelerometer.

I can successfully connect to the Ti SensorTag with the checking the UUID for the motion sensor (0xAA80) in the same way i can connect to the Wahoo searching for the CSC UUID (0x1816).

However if i want to perform a primary service discovery (ble_db_discovery_start) the result is zero, so i can´t find any service. What could be the reasons for that? The SensorTag works fine with Smartphone applications and so on.

[Vehring]

Now i execute sd_ble_gattc_characteristics_discover() before executing ble_db_discovery_start(). In this case the primary service discovery returns BLE_DB_DISCOVERY_COMPLETE but the characteristics of the motion service (0xAA80) all have UUID 0x000, but they should have 0xAA81 for the measurement data, 0xAA82 for the configuration and 0xAA83 so i can´t store any CCCD-handle. How can this happen? If i perform sd_ble_gattc_char_value_by_uuid_read the return value is 0x11. What should this mean? Invalid data?

[Petter Myhre]

CSC uses the Bluetooth SIG base UUID, but I don't think the other UUIDs you are looking for uses it. They probably use a proprietary base UUID. Could it be that you have skipped registering the base with the SoftDevice? And that you give an incorrect UUID to the database discovery module? Have a look at how it is done in ble_nus_c_init() in the ble_app_uart_c example.

[Vehring]

No it doesn´t use SIG base UUID. You gave me a good hint, i didn´t knew i have to register that proprietary base UUID at the softdevice.

I have to check but i have the hope it´s the problem i have.

[Vehring]

Unfortunately i still can´t discover services. I added the registering of the base UUID of the SensorTag which should be F0000000-0451-4000-B000-000000000000 according to link text

Is it sure that every proprietary service uses the UUID Type BLE_UUID_TYPE_VENDOR_BEGIN (0x02)?

In my program i hand over the UUID of the Movement Service (0xAA80) which i also use to identify my sensortag in the adv_report and then connect to it. This should be okay, right?

[Petter Myhre]

The first proprietary base UUID you add will have 0x02, the second 0x03 and so on. It doesn't matter how you connect to it. Maybe a sniffer trace would help explaining what is going on? You can use nRF Sniffer.