Input Voltage * Volts (V)

Reference Voltage * Volts (V)

Resolution * Bit depth

3.3V on 10-bit, 5V ref 2.5V on ESP32 (12-bit, 3.3V)

—

ADC value

Voltage → ADC

66%

0 Mid: 50% Max

ADC Value * Counts

Reference Voltage * Volts (V)

Resolution * Bit depth

ADC 512 on 10-bit, 5V ref ADC 2048 on ESP32 (12-bit, 3.3V)

— V

Input voltage

ADC → Voltage

50%

0V Mid: 50% Ref

Input Voltage (Vin) * Volts (V)

R1 (Top) * Ohms (Ω)

R2 (Bottom) * Ohms (Ω)

ADC Reference * Volts (V)

ADC Resolution * Bit depth

12V → 1.09V, 10-bit ADC 24V → 2.18V, 12-bit ADC

— V

ADC input voltage and value

Divider

Vin 12V → R1 10kΩ → Vout 1.09V → R2 1kΩ → GND