Arduino senzor napona

TThis module is based on principle of resistive voltage divider design, can make the red terminal connector input voltage to 5 times smaller.for Arduino analog input voltages up to 5 v, the voltage detection module input voltage not greater than 5Vx5=25V (if using 3.3V systems, input voltage not greater than 3.3Vx5=16.5V). for Arduino AVR chips have 10-bit AD, so this module simulates a resolution of 0.00489V (5V/1023), so the minimum voltage of input voltage detection module is 0.00489Vx5=0.02445V.
Output Interface : "+ " connected 5/3.3V, "-" connected GND, "s" connected for Arduino AD pins
By 3P connector, connect this module with the expansion of board for Arduino, not only makes it easier for you to detect voltage battery, can also use the IICLCD1602 LCD to display voltage.

Reference Code:
#include <Wire.h>

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);
}