First of all, thank you.
I already used the SdFat library downloaded from here: https://github.com/greiman/SdFat/tree/master/SdFat/src/FatLib
I hope it is the right version.
I am trying to reduce the power consumption of my project, but I still have some problems.
One of them is the rx led, which is always on when the SD has been initialized.
I used the following code (I was inspired by the Gammon's webpage http://gammon.com.au/Arduino/Temperature_Monitor.ino ):
// Data saving
dataString = String(pause) + "," + String(timer1) + "," + String(timer2) + "," + String(sR1)
+ "," + String(sR2) + "," + String(sR3) + "," + String(sR4) + "," + String(sR5) + "," + String(sR6) + "," + String(sR7); // convert to CSV
myFile.open("data.csv", O_WRITE | O_CREAT | O_AT_END);
myFile.close(); // close the file
} // end of data saving
The SD card is correctly initialized, but the rx led is always on and it is responsible for a higher power consumption.