Darkness Map Data Collection Device

Step 1: Parts You Need

Step 2: Solder Your Breakout Boards and Kits

Step 3: Set up the GPS Module

–5V pin to Arduino 5V pin
–Ground to Arduino Ground pin
–Clock pin to Arduino’s pin13
–DO pin to Arduino pin12
–DI pin to Arduino pin11
–CS pin to Arduino pin10

Now you’ll want to open an example from the SD card library, which comes with Arduino. We’ll be checking whether our MicroSD breakout board is wired up properly, and if the SD card is formatted correctly using the CardInfo sketch. Before you upload the code to the Arduino, make sure you change one line of code. The chipSelect pin should be set to 10, not 4.

const int chipSelect = 10;

Upload the code to the Arduino and turn on the serial monitor. If your serial monitor gives you a message that it can’t initialize the card, try reformatting it to FAT32 or FAT16 using your Disk Utility application. If you have further problems, follow the steps in the Adafruit tutorial.

Next let’s see if we can write files to our SD card. Open the Files example from the SD library. Make sure to change chipSelect to equal 10, not 4. Upload the code and turn on the serial monitor. If it successfully creates and removes the example.txt file then congratulations, you’re able to write to an SD card.

Next we want to see if we can get the Arduino to save our GPS readings to the SD card. Disconnect your Arduino from the computer. Put the GPS module back in place. In order to connect both the GPS and MicroSD card breakout board to 5V and Ground on the Arduino, we’ll want to bring the power and ground to the breadboard, and then connect it to each module.

Now, upload the following code to your Arduino. It’s best if the Arduino is back out on your window ledge so you can get a GPS reading. You can check to see what’s happening by opening the serial monitor, but make sure to change the baud rate to 115200 or else the characters won’t make much sense. You should be seeing rows of three values. First the longitude coordinate, next the latitude coordinate, and finally the unix timestamp.

#include “Wire.h”
#include “SD.h”
#include “SoftwareSerial.h”
#include “TinyGPS.h”
#include “RTClib.h”

const int chipSelect = 10;
RTC_Millis RTC;
File dataFile;

TinyGPS gps;
SoftwareSerial ss(3, 4);

void setup()
{
Serial.begin(115200);
Serial.print(“Initializing SD card…”);
ss.begin(9600);
pinMode(chipSelect, OUTPUT);
RTC.adjust(DateTime(__DATE__, __TIME__));

// see if the card is present and can be initialized:
if (!SD.begin(chipSelect)) {
Serial.println(“Card failed, or not present”);
// don’t do anything more:
while (1) ;
}
Serial.println(“card initialized.”);

// Open up the file we’re going to log to!
dataFile = SD.open(“GPStest.txt”, FILE_WRITE);
if (! dataFile) {
Serial.println(“error opening GPStest.txt”);
// Wait forever since we cant write data
while (1) ;
}
}

void loop()
{
DateTime now = RTC.now();
bool newData = false;

for (unsigned long start = millis(); millis() – start < 1000;)
{
while (ss.available())
{
char c = ss.read();
// Serial.write(c); // uncomment this line if you want to see the GPS data flowing
if (gps.encode(c)) // Did a new valid sentence come in?
newData = true;
}
}

if (newData)
{
float flat, flon;
unsigned long age;
int year;
byte month, day, hour, minute, second, hundredths;
gps.f_get_position(&flat, &flon, &age);
gps.crack_datetime(&year, &month, &day, &hour, &minute, &second, &hundredths, &age);
char sz[32];
sprintf(sz, “%02d/%02d/%02d, %02d:%02d:%02d,  “,
month, day, year, hour, minute, second);

Serial.print(“”);
Serial.print(flon == TinyGPS::GPS_INVALID_F_ANGLE ? 0.0 : flon, 6);
Serial.print(“, “);
Serial.print(flat == TinyGPS::GPS_INVALID_F_ANGLE ? 0.0 : flat, 6);
Serial.print(“, “);
Serial.println(now.unixtime());

dataFile.print(“”);
dataFile.print(flon == TinyGPS::GPS_INVALID_F_ANGLE ? 0.0 : flon, 6);
dataFile.print(“, “);
dataFile.print(flat == TinyGPS::GPS_INVALID_F_ANGLE ? 0.0 : flat, 6);
dataFile.print(“, “);
dataFile.println(now.unixtime());
}

dataFile.flush();
delay(500);
}

Now unplug your Arduino and eject the MicroSD card from the breakout board. Find the SD card adapter and insert it into your computer, either with a card reader or directly if you have an SD card slot. See if there is a text file called GPSTEST.TXT. If there is, yay! If not, then I’d try reformatting your card and trying to write to it again. Open the text file and make sure the data has been written. Sometimes the file gets created but no data gets saved, and if this is your case, check your wiring, and try following LadyAda’s SD card tutorials.