As I described in my previous build log, I messed up on the first PCB, however I reworked this to correct my mistake, but when I powdered the board up it was tripping the current limit on my bench PSU (set to 100mA), I assumed (incorrectly) I had messed up the distance sensor when I rotated it. As it turns out, the accelerometer was faulty.

Moments after sending the files to OSH Park for this project I went to order the parts only to discover the accelerometer I used was out of stock everywhere. I knew I had one in my parts bins but I wanted more. Fortunately, or unfortunately as the case should be, I managed to source 20 from a seller on AliExpress. I took no notice when assembling the first PCBs to the state of the pads on the accelerometer, but after some fault finding I decided to take a closer look. Photos below with AliExpress sources accelerometers on the left, and the new one i had from Farnell.

As seen through a little microscope...

The accelerometers have clearly been used and then removed, they were repackaged in tape to look original, I got lucky on the second one, but the first never worked, and to make matters worse, I found a stash of 10 new ones when I went to assemble a few more boards so I didn't even need the ones I ordered from AliExpress in the first place!