# Measuring High Voltage DC Using ESP32

I want to read high voltages, around 150VDC, using a ESP32.

I plan to put this as an input into the ESP32 ADC pin. But of course, i shouldn't have voltage that high on the input of a ESP32.

In ESP32 datasheet tells that ADC max input is 3.3 V with 12-bit resolution (0-4095). So, i just need to scale it down from 0-150 to 0-3.3 VDC.

So, i use simple voltage divider to achieve this.

Vout = (R2 / (R1+R2))  * Vin


if i want to scale it down about 1:45, then: R2 = 1kΩ R1 = 44kΩ

My question is,

1. Is this going to work?
2. How is the accuracy and stability?
3. Is it safe (when something wrong, not gonna break my ESP)?