I have built an MI Clouds that I am having some issues getting to work.
I installed the power circuit first, followed by the MCU circuit. I then flashed the stm32 using the mutable vagrant dev environment and an ST-Link V2 (via JTAG), but I made the mistake of only putting the bootloader on.
I continued to then finish off installing components to the board, but when finished and i came to power up I started having issues.
The LEDs would light up in a random fashion each time the board was powered. I was unable to flash the chip again, so I downloaded STFM32 ST Link utility and erased the chip. I was able to flash the bootloader (I think), but the rest of the flashing would fail. I tried this many times.
While trying to diagnose what was going wrong I found that the LM1117 (IC7) was getting very hot, and that pin 2 was only outputting about 0.85v instead of 3.3v
I have removed this regulator and tested it off the board and it appear to work ok, outputting the correct 3.3v, though it is not under any load when doing this.
I have checked for shorts to ground using the Eagle files as reference, but I am unable to find any. Not saying they are not there, I just cant find any
Resistance from the 3v3_A circuit to ground is 2.5K - I have no idea if that is relevant?
I am presuming I am unable to flash the STM32 properly as the +3v3_A power circuit is not fuctioning correctly, and the chip isnt getting the required voltage to work correctly.
I am not sure what to do next to try and solve this issue, and would appreciate any suggestions on where to look next.