Trying to connect Bluetooth BP cuff, but struggling with the "characteristic UUID" stuff

Questions about Thunkable BLE / BlueTooth
1

I’m very new to BLE stuff, and Thunkable, so please excuse my ignorance.

I’m trying to connect and collect data from a BLE blood pressure cuff, but I don’t have a clue what I’m doing.

I’ve got some documentation from the device manufactureres about the BLE structure and all that…

  • my biggest problem is trying to figure out the “characteristic UUID”

The documentation says something like “fff4”

image

  • but when I try and receive that, I get an error saying that the system can’t read that characteristic.
    • When I look for help online, I find LONG strings for the uuid - not 4 character strings.

What am I missing?

  • I’ve gotten as far as:
    • Scanning for a list of devices
    • Selecting and connecting to a device

image
image733×731 69 KB

It’s the UUID thing that’s tripping me up, I’m sure of it.

Anyone got any advice?

  • Thanks so much!
1 Like
2

Use this as your UUID
0000FFF4-0000-1000-8000-00805F9B34FB

1 Like
3

Thank you so much for your help!!

May I ask how you got all the extra characters?

  • Are they industry standard or something???
1 Like
4

This is the default or base UUID for all characteristic IDs if not set by the factory.

The default is 00000000-0000-1000-8000-00805F9B34FB
If the manufacturer is giving you only 4 digit then it is assumed that you need to use the default UUID. It starts with 8 hexadecimal digits and you need to add your 4 digit hexadecimal number as the second part of it. So instead of all zeros it would be 0000 plus your code FFF4

2 Likes
5

Thank you! @muneer

Cheers

1 Like
6

This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.