So I've been playing with the esp8266 controller lately and today my Usb Host Mini came in that I wanted to connect. So for this I followed the following tutorial https://www.hackster.io/139994/plug-any-usb-device-on-an-esp8266-e0ca8a

The only thing is that I didn't do the following, because I wanted to see that it actually wouldn't work without damaging the Usb Host Mini.

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Now I am wondering, because I didn't do that, and just went on with the wiring, did I actually kill my ESP8266 now? Whenever I remove all the wires, and just connect the ESP8266 to my computer, it just won't show up in the ports.

If I did kill it, what did I actually do here? Did I allow 5V to run through the board and did I fry it that way? If I would've actually made the cut shown above, would it have lived? (Because I think what the cut does, is it stops the 5V from going through the circuit.)

  • Did you connect 5V power source and 3.3V power source to the ESP8266? Sep 25, 2019 at 17:30
  • @FilipFranik Yes I did indeed
    – Jordy
    Sep 25, 2019 at 17:50

1 Answer 1


Well if it doesn't work then it doesn't work so a safe bet is that chip is damaged.

I found this document. It states:

VBUS pad and jumber can be used to provide 5V to VBUS. By default VBUS is connected to 3.3V; certain USB devices may have issue with this.

So I deduce that this is connected directly to 3.3V rail of the chip. Providing 5V without opening the jumper (cutting the trace) is the same as putting 5V at the 3.3V pin.

3.3V. Power pin of the shield. Do not supply 5V to this pin - MAX3421E won't be able to detect devices on VBUS and may also be damaged!

Apparently the "proper" way of doing things is to actually unsolder that jumper or cut the trace.


  • Hmm alright that's a bummer, would this also mean that I killed my Usb Host Mini? Or did I just kill the esp8266? I'll find out tomorrow, once I get a new esp8266, but I thought maybe you know. It would suck if I had to buy another Usb Host Mini, since they're quite expensive.
    – Jordy
    Sep 25, 2019 at 20:20
  • I'm pretty sure that the chip on the mini is fried (if it wasn't then PC would detect an unknown device plugged in) The USB Host Mini clone is just 4 USD on Aliexpress with free shipping. Sep 25, 2019 at 20:52

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