We are working on a custom board based on DA14681 and a unusual problem occured.
We are currently testing 4 to 5 boards with same hardware and same firmware. But only one of them is restarting and upon debugging we found out that, that particular is going into hard_fault state. Upon more debugging it is found that when ad_i2c_write() is called, it goes into hard fault state.
Two wierd things regarding this :
1 - it is only happening on one board out of 5 boards, same hardware same firmware.