My dad donated me a TrackR Bravo and the first thing I did was a brutal teardown. First I desoldered all the components and marked their location. Then I measured their value. Some components I could not yet measure and they turn out to be inductors. My multimeter does not support inductors, but the one at work maybe does do.
Here is the PCB in all it’s glory. The inner layer I cannot tell for sure, I cannot see the wires running their without doing destructive work on it. I want to reassemble the device again so grinding down to the inner layer is a no-go. Maybe an X-Ray image would tell where the tracks are going. With a multimeter I measured which wires are connected where so it is probably a correct representation of what is going on in there.
If all goes well I can resolder the controller, that is the most critical component to solder because it has a huge thermal pad. I will need to use a heatgun to put it on again.
Also I will try to find out which firmware is running and to see if I can also put new firmware in to give it alternative functionality. Like it would be fun if you could pair a couple of TrackR devices together and when you press the button on one of them, all TrackR devices are beeping. Maybe use a morse code to find a specific device. When you have one connected to your keys and another one to your wallet, you cannot find your wallet with your keys, you first have to find your phone and then find your wallet . ..
The schematic needs to be reversed as well, I am working on that now. Also it would be nice to see if I can also readout the firmware of the device. Maybe I can read it using the SWD (Serial Wire Debug) interface.