# Trying to connect Bluetooth BP cuff, but struggling with the "characteristic UUID" stuff **URL:** \ **Category:** BLE / BlueTooth\ **Tags:** bluetooth\ **Created:** [April 26, 2022, 1:57pm UTC](https://community.thunkable.com/t/trying-to-connect-bluetooth-bp-cuff-but-struggling-with-the-characteristic-uuid-stuff/1849525 "2022-04-26T13:57:07Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![multitech-visions](https://sea1.discourse-cdn.com/flex015/user_avatar/community.thunkable.com/multitech-visions/32/130537_2.png) [@multitech-visions](https://community.thunkable.com/u/multitech-visions)\ **Post date:** [April 26, 2022, 1:57pm UTC](https://community.thunkable.com/t/trying-to-connect-bluetooth-bp-cuff-but-struggling-with-the-characteristic-uuid-stuff/1849525/1 "2022-04-26T13:57:07Z")
_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](https://us1.discourse-cdn.com/flex015/uploads/thunkable/original/3X/3/b/3b79bd92a63a21c0056f4401eb1152df282f63d6.png) - 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](https://us1.discourse-cdn.com/flex015/uploads/thunkable/original/3X/5/3/53a418dc9e8dc00f30b2e5fa8c0208774ba0a1e7.png) _It’s the UUID thing that’s tripping me up, I’m sure of it._ ## _Anyone got any advice?_ - _Thanks so much!_ ---
**Author:** ![muneer](https://sea1.discourse-cdn.com/flex015/user_avatar/community.thunkable.com/muneer/32/75210_2.png) [@muneer](https://community.thunkable.com/u/muneer)\ **Post date:** [April 26, 2022, 2:05pm UTC](https://community.thunkable.com/t/trying-to-connect-bluetooth-bp-cuff-but-struggling-with-the-characteristic-uuid-stuff/1849525/2 "2022-04-26T14:05:38Z")
Use this as your UUID **0000FFF4-0000-1000-8000-00805F9B34FB** ---
**Author:** ![multitech-visions](https://sea1.discourse-cdn.com/flex015/user_avatar/community.thunkable.com/multitech-visions/32/130537_2.png) [@multitech-visions](https://community.thunkable.com/u/multitech-visions)\ **Post date:** [April 26, 2022, 2:18pm UTC](https://community.thunkable.com/t/trying-to-connect-bluetooth-bp-cuff-but-struggling-with-the-characteristic-uuid-stuff/1849525/3 "2022-04-26T14:18:42Z")
_Thank you so much for your help!!_ # May I ask how you got all the extra characters? - Are they industry standard or something??? ---
**Author:** ![muneer](https://sea1.discourse-cdn.com/flex015/user_avatar/community.thunkable.com/muneer/32/75210_2.png) [@muneer](https://community.thunkable.com/u/muneer)\ **Post date:** [April 26, 2022, 2:27pm UTC](https://community.thunkable.com/t/trying-to-connect-bluetooth-bp-cuff-but-struggling-with-the-characteristic-uuid-stuff/1849525/4 "2022-04-26T14:27:28Z")
> [@multitech-visions](#): > > May I ask how you got all the extra characters? 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 ---
**Author:** ![multitech-visions](https://sea1.discourse-cdn.com/flex015/user_avatar/community.thunkable.com/multitech-visions/32/130537_2.png) [@multitech-visions](https://community.thunkable.com/u/multitech-visions)\ **Post date:** [April 26, 2022, 2:47pm UTC](https://community.thunkable.com/t/trying-to-connect-bluetooth-bp-cuff-but-struggling-with-the-characteristic-uuid-stuff/1849525/5 "2022-04-26T14:47:04Z")
# Thank you! @muneer ![Cheers](https://us1.discourse-cdn.com/flex015/uploads/thunkable/original/3X/0/6/069e94c3b98441b6cd469b921fc25d2405d29581.gif) ---
**Author:** ![system](https://us1.discourse-cdn.com/flex015/uploads/thunkable/original/3X/0/f/0f59f292712368bce16ff80133ae10de8a6f27e8.png) [@system](https://community.thunkable.com/u/system)\ **Post date:** [July 25, 2022, 2:47pm UTC](https://community.thunkable.com/t/trying-to-connect-bluetooth-bp-cuff-but-struggling-with-the-characteristic-uuid-stuff/1849525/6 "2022-07-25T14:47:50Z")
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