Datasheet

to kick start the logging. If you have this on you basically can't have it run away from

the computer so we'll keep it off (set to 0) for now. If you want to turn it on, set this to

The other defines are easier to understand, as they are just pin defines

redLEDpin is whatever you connected to the Red LED on the logger shield

greenLEDpin is whatever you connected to the Green LED on the logger shield

photocellPin is the analog input that the CdS cell is wired to

tempPin is the analog input that the TMP36 is wired to

Objects and error()

Next up we've got all the objects for the RTC, and the SD card chip select pin. For all our

shields we use pin 10 for SD card chip select lines but Ethernet shields use pin 4

Next is the error function, which is just a shortcut for us, we use it when something Really

Bad happened, like we couldn't write to the SD card or open it. It prints out the error to the

Serial Monitor, turns on the red error LED, and then sits in a while(1); loop forever, also

known as a halt

Setup

RTC_DS1307 RTC; // define the Real Time Clock object

// for the data logging shield, we use digital pin 10 for the SD cs line

const int chipSelect = 10;

// the logging file

File logfile;

void error(char *str)

{

Serial.print("error: ");

Serial.println(str);

// red LED indicates error

digitalWrite(redLEDpin, HIGH);

while(1);

}

void setup(void)