Hi all! This should be simple, but I am hitting a snag and can't find an answer with google. Objective I am using ESP01-S to measure if an external power source is sending me 12V or 0V. I use a voltage divider to drop the voltage down. Here is the circuit (I use a nano in the diagram but in reali…

As long as you don't use Serial in your code (which you didn't post) you can use GPIO1 and 3 as regular I/O pins. How do you communicate with the device, to know whether you detect voltage or not? What voltages does your multimeter show at the ESP-01 pin? When using a NodeMCU you can use D1, D2, …

ESP01-S voltage divider short circuit?

Projects General Guidance

LarryD January 22, 2024, 2:41am 3

Are you connecting anything to the lower power + rail, maybe 3V3 ?
If 12v, is there a common GND to the controller ?
Images of actual wiring is helpful.

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ESP01-S voltage divider short circuit?

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