it's alive and talking to me!
as usual, the SPI peripheral implementation in it is kinda finicky, and it actually doesn't work with the default #GlasgowInterfaceExplorer SPI controller (because it's not fully compliant with SPI, oops)
i'll fix the SPI controller in a bit
this thing doesn't seem to have a magnetometer or a barometer, it's just an accelerometer and a gyroscope. not even very good ones, they're probably on par with what your cellphone has, if not worse
i think some enterprising company (possibly Shenznen Firepower Control Co. Ltd. based on @poppyhaze's research) has realized they can make a lot of money selling ADIS16488-style devices that only barely work at a half of their sticker price from AD
oh... it has a GD32F103 inside. there are even, conveniently, pads with SWD routed to them
firmware dumping time? firmware dumping time.
it looks like sometimes it works and sometimes it doesn't
very bold of a vendor to call it a "good device" when in fact it seems to be bad
did someone build the firmware with -funroll-loops or what
this is a part the code that copies static mutable data into RAM from Flash. it goes on for kilobytes
OH I GOT IT
i finally tracked down the source of this device, and also the gyroscope vendor
the WM_KT-EX9-10_2.12_GD103.bin in the firmware name most likely refers to the gyro:
https://en.ktjmyq.com/html/2024/MEMS_0526/141.html
i'm wrong. the KT-EX9-1 device has a public datasheet and some key values don't match
this could be a custom one-off or something?