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Hi, friends!!! I need some help here.

I'm experiencing some strange issues when I try to log my CT readings to an SD card.

Somehow it seems that EmonLin is not compatible with the SD library.

My wiring is exactly the one presented here: http://openenergymonitor.org/emon/buildingblocks/how-to-build-an-arduino-energy-monitor-measuring-current-only

The sketch works fine when:

- the sd card is not present (so, SD is not really being used); or

- the analog input used to read the CT sensor is grounded.

With the original circuit and the SD card present, the arduino resets all the time.

Here is my code:

#include <EmonLib.h>
#include <SD.h>

EnergyMonitor emon1;

void setup()
{
Serial.begin(9600);
Serial.println("\n\nStarting...");

// initialize sd card
Serial.print("- initializing sd card...");
pinMode(10, OUTPUT);
if (!SD.begin(4)) { // chipselect is pin 4
  Serial.println(" failed.");
} else {
  Serial.println(" done.");
  Serial.print("- opening datalog.txt...");
  File dataFile = SD.open("datalog.txt", FILE_WRITE);
  if (dataFile) {
   Serial.println(" done.");
   dataFile.close();
  } else {
   Serial.println(" failed.");
  }
}
Serial.print("- initializing energy monitors...");
emon1.current(0,30);
Serial.println(" done.");
Serial.println("Started!\n");
}

void loop()
{
// read current
float irms = emon1.calcIrms(1480);

// publish results
Serial.print(irms * 127.0);
Serial.print(" ");
Serial.print(irms);

// log results
File dataFile = SD.open("datalog.txt", FILE_WRITE);
if (dataFile) {
  char aux[12];
  dtostrf(irms * 127, 10, 8, aux);
  dataFile.print(aux);
  dataFile.print(",");
  dtostrf(irms, 10, 8, aux);
  dataFile.print(aux);
  dataFile.close();
  Serial.println(" >> saved");
}
else {  // if the file isn't open, pop up an error:
  Serial.println(" >> save error");
}

}

And here is the wiring: