Hi, I'm new to this forum so I hope I'm not breaking any rules or posting in the wrong place.
I'm having an issue pairing the Wemos D1 Mini (v2.2.0) and its DC shield (v1.1.0).
So far I have killed 3 DC shields and 2 ESPs.
What I have figured out is that everything works great when connected with 12v to the DC shield, but connecting 5v from USB when the DC shield is connected but not powered overheats, kills and shorts the DC shields 5v supply.
Since the USB port is used to update the firmware, it's really annoying that I can't use the USB port after soldering everything together.
Is it my fault for not understanding that the USB port if completely off limits when the DC shield is attached? Or is this not the expected behaviour with the shield?
I don't know the exact sourcing of the ESP and the shield as I'm buying it from a local reseller, but to my inexperienced eyes, they look legit. The Wemos D1 Mini might be missing a diode between the usb port and the rest of the board, but that should only prevent current from going back from the board to the usb port and not affect anything in this situation, right?
Appreciate any help as I'm quite confused why 2 parts that are built to work together do not seem to be compatible with each other.
I've yet to use my Wemos D1s but i'll have a go at answering your question. The schematic for the DC Power Shield on the Wemos website shows the 5V output going to the VBUS pin on the D1 Mini.
My guess is that the USB 5V going into the Wemos board is fighting the 5V coming out of your DC board.
It's a bit of a hack, but you may be able to get around the issue by having a short extension USB cable (say 10cm) that you can cut open the outer cable covering to expose the USB wire. Assuming standard USB colour codes on the cores, cut the red one and that should stop USB power getting to your board. The problem you then have is that the USB wire cores are quite fragile so you may need a bit of duct tape (or similar) to wrap around the cable to give it a bit of its strength back.
I have only tested it with only USB 5v connected, so there shouldn't be a fighting current. My thinking has been, based on the same schematic you linked, that the 5v current going back to the DC shield is frying it. If the shield had a diod between the regulating IC and VBUS, it might have been fine.
That is a solution I have also though of but not used. The problem is that I am not the only one that is going to interact with it and I fear that if someone sees a USB port, they might try to use it and fry everything.
