What happens if you have nothing connected to your NodeMCU, except the USB cable to your PC?
Pete.
same as the case, when i first connect it to the laptop and then put on the plugbar. Of course only if I already uploaded my sketch.
When you are able to flash it with code then you should try a simple sketch that just serial prints a “Hello World” message every few seconds then with this uploaded see if you are able to flash it normally.
Pete.
it is really strange. I can flash the ESP (but only in the way mentioned in the quote) and load up an empty sketch. But although i uploaded the empty sketch when i remove the wires fof the L9110s from my ESP the chip runs into the error loop. When I leave everything connected, it works fine (Picture 1). So I tried to remove every single wire one after the other and found out that the problem is with GPIO2 (D4). The ESP only works if the L9110s is connected to GPIO2, ground and to my external battery (Picture 2). Everytime I just remove the wire on GPIO4 or disconnect the L9110s from the battery, the error loop comes again (of course it also comes when nothing is connected to the ESP at all) (Picture 3).
It is so strange and I almost tried every possible wirings but still cannot fix the problem.
I uploaded my schematic so you can have a look at the wiring if you want to.
best regards
Timo.
GPIO2 must be HIGH at boot-up.
Presumably you’ve burnt-out the built-in pull-up resistor. Maybe adding a 10k resistor between GPIO2 and 3v3 will allow it to boot into ‘run’ mode without the other stuff connected.
Pete
It worked! But I needed to add an 1k resistor between GPIO2 and 3V3.
Do you also have a recommedation to prevent such a case next time and still use the wiring mentioned in the quote?
Thank you for your help!
Timo.
I’d put a meter on the connections of your ESP and motor controller and run through a few different scenarios with controlling the motors to see what sort of voltage readings you’re getting.
If you have a meter that can do peak hold then that will make things easier.
You might also want to see what sort of current is being drawn on GPIO2 in particular.
If there’s an issue then maybe an opto isolator is the solution, or a level shifter board.
Pete.
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