I recently designed a PCB to hold an Arduino Nano, IMU and other components. I'm using this platform as the fly computer of a homemade drone. This is one of my first PCB designs and I'm not an expert, so perhaps I'm missing something obvious here.
Now let us get to the problem. I started by testing each component, the Arduino (CPU), CPU + IMU, CPU + HC-05, CPU + HC-05 + RTX(RC receiver). At this last point, the Arduino stopped responding, the RX TX and POW LEDs stay ON all the time. I can't upload new software to it.
I noticed that the ATmega328 was extremely hot! I tried powering the Arduino from the +5V and same result (LEDs stuck ON).
During testing, I had a 3SLiPo battery connected to the PW(top right) of the PCB, and the Arduino was also connected to my PC through the USB port.
Do you see any issues with the PCB design itself?
List of the components tested: