Datasheet

Next is the sensor logging code

int photocellReading = analogRead(photocellPin);

delay(10);

int tempReading = analogRead(tempPin);

// converting that reading to voltage, for 3.3v arduino use 3.3

float voltage = (tempReading * 5.0) / 1024.0;

float temperatureC = (voltage - 0.5) * 100.0 ;

float temperatureF = (temperatureC * 9.0 / 5.0) + 32.0;

logfile.print(", ");

logfile.print(photocellReading);

logfile.print(", ");

logfile.println(temperatureF);

#if ECHO_TO_SERIAL

Serial.print(", ");

Serial.print(photocellReading);

Serial.print(", ");

Serial.println(temperatureF);

#endif //ECHO_TO_SERIAL

digitalWrite(greenLEDpin, LOW);

}

This code is pretty straight forward, the processing code is snagged from our earlier tutorial.

Then we just print() it to the card with a comma seperating the two

We finish up by turning the green LED off