This module is based on resistance points pressure principle, and it can make the input voltage of red terminal reduce 5 times of original voltage.
The max Arduino analog input voltage is 5 V, so the input voltage of this module should be not more than 5 V x 5 = 25 V ( if for 3.3 V system, the input voltage should be not more than 3.3 V x 5 = 16.5 V ).
Because the Arduino AVR chip have 10 bit AD, so this module simulation resolution is 0.00489 V (5 V / 1023), and the input voltage of this module should be more than 0.00489 V x 5 = 0.02445 V.
– Voltage input range : DC0-25 V
– Voltage detection range : DC0.02445 V-25 V
– Voltage analog resolution : 0.00489 V
– DC input interface : red terminal positive with VCC, negative with GND