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);
}