compiling error with attiny45

i use now serial.write instead of serial.print. But i retrieve '??øfxfx??'. Could i translate that into the right data ?

I think you use the wrong baudrate.

If you are using TinyDebugSerial you can only use 9600, 38400 or 115000

The outputpin used by TinyDebugSerial is PB3, so if you move the sensorpin to PB4, you have a working sketch.

http://arduino.cc/forum/index.php/topic,91125.0.html

int sensorValue = 0;
int sensor = 4;
float var = 0.0;
float temp = 0.0;
void setup()  
{
    Serial.begin(9600);
  Serial.println("Hello, world?");
  pinMode(sensor, INPUT);
}
void loop()
{
sensorValue = analogRead(sensor); 
var = (sensorValue * 5.00) / 1024.00;
temp = var * 52.0833 - 20.833;                     
Serial.print("Temp ");
Serial.println(temp);
delay(1000);
}