I’m a newbie, but I successfully installed a d1 mini with dc power shield and relay shield to switch 12 volts. However, the next time I tried to duplicate the d1 mini worked at first and then smoke. I thought I must have shorted something. I started over and had the same experience. I’ve now checked several of the dc shields. 12.6 volts in to the barrel jack and 5 v on the 5 volt pin, however I don’t measure any voltage on the 3 v pin relative to ground. I also had some boards that convert 12 v to 5 volts or 3.3 v. Much to my surprise some of the boards delivered 12 volts to the 5 volt pin.
Any suggestions, I now fried two, d1 mini boards.
Thanks,
Steve