#include <SoftwareSerial.h>
SoftwareSerial mySerial(11,10);
unsigned char data[4];
int distance;
int i;
void setup()
{
Serial.begin(9600);
mySerial.begin(9600);
}
void loop()
{
while (i < 4)
{
if(mySerial.available())
{
data[i]=mySerial.read();
i++;
}
}
i = 0;
int sum=(data[0] + data[1] + data[2]) & 0xFF;
if(data[0] == 0xFF && sum == data[3])
{
distance=(data[1]<<8)+data[2];
Serial.print(distance/10);
Serial.println(" cm");
}
}