0

I am setting up an Arduino to collect temperature and pressure data, and I want to broadcast that data via bluetooth.

My question boils down to what allocated UUID is best for my characteristic, and I think it would be great if that UUID specified the unit.

On BlueTooth Sig's website there is a pdf file with a bunch of 'allocated' UUIDs of which there is a column called 'Allocation Type' and under that column there are two categories of interest 'GATT Unit' and 'GATT Characteristic and Object Type'.

The UUID '2A6E' is a GATT Characteristic and Object Type and it appears to be what most people use to define a temperature characteristic.

The UUID '27AC' is a GATT Unit and it describes/allocated for 'thermodynamic temperature (degree Fahrenheit)'.

I am wondering if I can use a GATT Unit UUID to declare my characteristics so that I also get to convey the unit along with the data.

The pdf file showing all the different allocated UUIDs can be found here: https://btprodspecificationrefs.blob.core.windows.net/assigned-values/16-bit%20UUID%20Numbers%20Document.pdf

Improve this question
2
  • Have you checked file:///C:/Users/km72670/Downloads/GATT_Specification_Supplement_v5.pdf to see which one suits your use case better ? It appears that if you're sending a 2A6E, its Celcius. If 0x2A1C, you can send a bit that says C or F. See bluetooth.com/wp-content/uploads/Sitecore-Media-Library/Gatt/… Vs bluetooth.com/wp-content/uploads/Sitecore-Media-Library/Gatt/… Explore and experiment and let us know what you learned.
    – kalyanswaroop
    Commented Jan 12, 2022 at 17:57
  • You are correct in that 2A6E is in Celcius. I have a short bit of code doing that now. I tried using 2A1C to send farenheight, but I am running into problems with formating. I think this weekend I will do some more digging to figure out how to properly format values when accompanied with flags. The GATT Supplement was very helpful.
    – helpful_rabbit
    Commented Jan 18, 2022 at 13:10

0

Reset to default

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.