BT121 evaluating kit update

Bluegiga - now owned by Silicon Labs - makes pretty nice RF modules. I think I've mentioned their WLAN modules previously; not as cheap is those ESP8266-based ones, but at least these come with pre-tested and with actual paperwork needed for properly done CE marking & DoC (although I've heard that some ESPs these days do have necessary CE paperwork too)

Now, I just bought evaluation kit for BT121 (Bluetooth module), hoping to be able to use it to develop my new embedded BT library on PC without having to build actual hardware for it yet. When I can connect development kit with USB to PC and write and run the software there, it makes things so much easier.

I plugged USB in the development kit and ran their own interactive BGTool. Nifty one, that; it allows you to interactively run commands to the module, showing content of command, response and event packets, making starting up with module much easier as you don't necessarily need to read through full loooong API manual to get things started. 

Except no. Didn't work.

The development kit is by default in demo mode where you can connect to it various ways - remotely, serially and whatnot - but not control it directly via API like I wanted to. And the manual says absolutely nothing on how you can actually write - or even upload - your own software package to it!

I almost - almost - wrote entire thing off as wasted money. Just 100-ish € or so, but nevertheless.

Now, the very basic setup the chips (as in, on reel intended for PCB assembly) would be more than sufficient for my needs, though. 115kbps serial link and raw API commands I want to use to control it. With that knowledge (okay, assumption) and few educated guesses I was able to upload the software on the kit anyway. Despite completely useless instructions. Nice.

So if you want to update it too, here's quick how-to:

Set up the board as quick start guide instructs (especially "USB to UART" converter, that's needed).
Set board to be powered by USB.
Plug out current sense jumper labeled BAT, below the BNC connector, and plug it in so that it shorts BOOT0 pin (slightly below and to the left of header you took it from) to 3V3.
Press "Reset module".
Open BGTool, then go to "View -> Upload tool".
Select "project.xml" as project, and "bt121_bgapi_uart115k" as binary.
Change port to correct one, and hit Upload.
And if everything goes well, you should see green bar flashing and shortly it's done.
Take out jumper from BOOT0 and replace it to its original position.
Reset module again.

And now you should be able to connect to it via Interactive view.