I'm back for a bit and have found a slight annoyance. Recently I acquired a rather nice multimeter that has a lot of functionality - data logging, a nice screen, and just an all-round improvement to what I had previously. This is made by Uni-T, a brand with mixed acceptance in the community, but the UT181a is one of their flagship models and I must say it is very nice indeed.
This came with a USB cable for transferring data to a PC, which works great. I also ordered the UT-D07A, a small bluetooth adapter that allows wireless communication. Sounds great, right?
Sadly I've found the phone app pretty rubbish - on iOS it crashes, and on Android it seems to frequently disconnect. The PC app has no ability to connect over bluetooth, which I was really hoping to achieve.
So - time to hack together something that does what I want!
After some initial investigation, I downloaded the Android APK package and used an online decompiler to look at the source code - something which was surprisingly very easy to do. This was apparently all written in Java; I mostly hate Java as I really don't understand it, but a lot of it pointed to Bluetooth LE calls. I downloaded a simple bluetooth sniffer app, and I could see that this little guy sends out "advertisements", that I currently have not been able to read (yet).
Recently I've had lots of help from @macaba working with some C# stuff. Handily, there are quite a few C# examples for dealing with Bluetooth LE data. I hope to write a simple app to receive the data the little bluetooth thing streams out and have at the end of it my data remotely displayed!