stin88 wrote: ↑19 Oct 2019, 19:00
succeded to upload arduino code to esp, recalculate the v-divider, R1=1,1kohm and R=100ohm and i get 0,75voltage when esp is not power on, when i power on the esp8366, it gives me around 1voltage, why? :S
For what schematic? The one above your post?
And what voltage do you use? (at what pins in the schematic do you apply the voltage?)
In the schematic above your post, R1 is not really part of the voltage divider, more like a current limiter.
Also it depends on the used ESP module if there is already a voltage divider present.
If you have a resistor between the GND of the power and the GND of the ESP, then you may introduce a higher voltage drop when using more current.
So please show what schematic you are using.