/* SD card datalogger
This example shows how to log data from three analog sensors to an SD card mounted on the YunShield/Yún using the Bridge library.
The circuit: * analog sensors on analog pins 0, 1 and 2 * SD card attached to SD card slot of the YunShield/Yún
Prepare your SD card creating an empty folder in the SD root named "arduino". This will ensure that the Yún will create a link to the SD to the "/mnt/sd" path.
You can remove the SD card while the Linux and the sketch are running but be careful not to remove it while the system is writing to it.
created 24 Nov 2010 modified 9 Apr 2012 by Tom Igoe adapted to the Yún Bridge library 20 Jun 2013 by Federico Vanzati modified 21 Jun 2013 by Tom Igoe
This example code is in the public domain.
http://www.arduino.cc/en/Tutorial/YunDatalogger
*/
void setup() { // Initialize the Bridge and the Serial Bridge.begin(); Serial.begin(9600); FileSystem.begin();
delay(5000); // wait for Serial port to connect. Serial.println("Filesystem datalogger\n"); }
void loop() { // make a string that start with a timestamp for assembling the data to log: String dataString; dataString += getTimeStamp(); dataString += " = ";
// read three sensors and append to the string: for (int analogPin = 0; analogPin < 3; analogPin++) { int sensor = analogRead(analogPin); dataString += String(sensor); if (analogPin < 2) { dataString += ","; // separate the values with a comma } }
// open the file. note that only one file can be open at a time, // so you have to close this one before opening another. // The FileSystem card is mounted at the following "/mnt/FileSystema1" File dataFile = FileSystem.open("/mnt/sd/datalog.txt", FILE_APPEND);
// if the file is available, write to it: if (dataFile) { dataFile.println(dataString); dataFile.close(); // print to the serial port too: SerialUSB.println(dataString); } // if the file isn't open, pop up an error: else { SerialUSB.println("error opening datalog.txt"); }
delay(1000);
}
// This function return a string with the time stamp String getTimeStamp() { String result; Process time; // date is a command line utility to get the date and the time // in different formats depending on the additional parameter time.begin("date"); time.addParameter("+%D-%T"); // parameters: D for the complete date mm/dd/yy // T for the time hh:mm:ss time.run(); // run the command
// read the output of the command while (time.available() > 0) { char c = time.read(); if (c != '\n') { result += c; } }
return result; }