This module is designed based on the principle of resistor divider to reduce the input voltage of the terminal interface by 5 times. The maximum input voltage of the Arduin is 5V. The input voltage of the voltage detection module cannot be greater than 5V × 5 = 25V (if 3.3V is used) System, the input voltage can not be greater than 3.3Vx5 = 16.5V). Because the AVR chip used by Arduino is 10-bit AD, the analog resolution of this module is 0.00489V (5V/1023), so the voltage detection module detects that the input minimum voltage is 0.00489V×5=0.02445V.
Voltage input range: DC0-25V
Voltage detection range: DC0.02445V-25V
Voltage analog resolution: 0.00489V