about UUID

[hunter]

Is it possible to make a services like this： services UUID : 55550001-5555-5555-5555-55555555555 characteristic UUID : 55550001-4444-4444-4444-444444444444

[Pål Håland]

Hi Hunter,

It is possible to create a service with characteristics like that, but the recommended way is to create a base UUID at www.itu.int/.../generate_uuid.aspx (so that you get a unique UUID) or you can generate it based on www.itu.int/.../X.667-E.pdf.

When you have generated it, you can use the function call sd_ble_uuid_vs_add.

Example:

Generated UUID 7298d7a0-0c38-11e6-ac45-0002a5d5c51b

ble_uuid128_t vs_uuid = 
    {0x1b, 0xc5, 0xd5, 0xa5, 0x02, 0x00, 0x45, 0xac, 0xe6, 0x11, 0x38, 0x0c, 0x0, 0x0, 0x98, 0x72};
// Notice that byte [12-13] is set to 0 instead of 0xd7a0, 
// this is because the this array is stored and then combined with the ble_uuid_t type.
uint8_t vs_uuid_id;

uint32_t errcode = sd_ble_uuid_vs_add(vs_uuid, &vs_uuid_id);

// Now you can use this uuid for a service
ble_uuid_t my_uuid = {0x0001, vs_uuid_id};
errcode = sd_ble_gatts_service_add(type, &my_uuid, &handle);
// Service UUID read from peer 72980001-0c38-11e6-ac45-0002a5d5c51b

my_uuid.uuid = 0x0003; //Change the UUID for the characteristic
ble_gatts_attr_t my_attr;
my_attr.p_uuid = &my_uuid;
errcode = sd_ble_gatts_characteristic_add(handle, &char_md, &attr_md, &char_handles);
// Characteristic UUID read from peer 72980003-0c38-11e6-ac45-0002a5d5c51b

Similarily you can use the same function to create two differen vs_uuid's like you did in your question, but it is better to stick to one random generated UUID as this will kind of be your unique UUID.

[hunter]

In you way. service UUID：72980000-0c38-11e6-ac45-0002a5d5c51b characteristic UUID: 72980003-0c38-11e6-ac45-0002a5d5c51b

This is not what I want. I want this: service UUID：72980000-0c38-11e6-ac45-0002a5d5c51b characteristic UUID: 72980003-ffff-ffff-ffff-ffffffffffff I can change FFFF to anythings.