I2C communication between arduino and uvga

Projects Networking, Protocols, and Devices
15

What you should have is:

byte old_value = 0;

void loop()
{
   unsigned int turbo = analogRead(3);
   byte new_value = map(turbo, 0, 1024, 0, 30);
   if(new_value != old_value)
   {
      Serial2.write(new_value);
   }
   old_value = new_value;
}

Writing to the uvga only when the value changes is a good idea. Delaying after doing so is not.

Note that the old and new values are based on the mapped values, not those read from the map sensor.

The upper limit of the from range, by the way, should be 1023, not 1024.