Introduction:
This module is based on a resistive divider principle design, make the interface terminal input voltage reduced 5 times, A rduino analog input voltage up to 5V, then the input voltage of the voltage detection module can not be greater than 5V × 5 = 25V (if used 3.3V system, the input voltage can not exceed 3.3Vx5 = 16.5V). Because A rduino AVR chips used in 10 AD, so the resolution of the analog module is 0.00489V (5V / 1023), so the voltage detection module detects a minimum input voltage of 0.00489V × 5 = 0.02445V.
 
Parameter:
Voltage input range: DC0-25V
Voltage detection range: DC0.02445V-25V
Voltage analog resolution: 0.00489V
Wiring:
DC input connector:
 
the positive terminal connected to VCC,
the negative connected toGND
Output interface:
"+" is 5 / 3.3V,
"-" then GND,
"s" A rduino connected to the AD pin
Code:
#include

int val11; 
int val2;

void setup() 
{   
 pinMode(LED1,OUTPUT);   
 Serial.begin(9600);   
 Serial.println("Emartee.Com");   
 Serial.println("Voltage: ");   
 Serial.print("V"); 
} 
void loop() 
{       
 float temp;       
 val11=analogRead(1);       
 temp=val11/4.092;       
 val11=(int)temp;//       
 val2=((val11%100)/10);       
 Serial.println(val2);          
 delay(1000);