Raspberry PI, TTL to RS232 and RS485

[funvill]

Got the boards back and populated all the components. Plugged it in and the board got hot! unplugged it immediately. After a while of searching we found the problem.

It looks like the extra copper that they put around the mounting hold bridged the 5V and GND plane. We temporarily fixed it in this version by cutting a trace and removing 5V from the short, and we will make changes to the board in the next version.

This process has been super interesting and rewarding so far.

[TomKeddie]

@funvill

It looks like the extra copper that they put around the mounting hold bridged the 5V and GND plane. We temporarily fixed it in this version by cutting a trace and removing 5V from the short, and we will make changes to the board in the next version.

@TomKeddie

The supply track looks really close to the right hand mount point of P1.

Argh this was the error in the cad I was referring to when I asked if you ran DRC. This is not a mfg error, its design unfortunately (I’ve forgotten DRC many times - one last change and …).

BTW, always power on a new board with a current limiting power supply set low.