Maybe it is not opening the file? You should check.
myFile = SD.open(filename);// Abrimos o arquivo que foi solicitado
if(!myFile) Serial.println("file open failed");
edit: The funny y = ÿ = 255 = -1 = fail.
Maybe it is not opening the file? You should check.
myFile = SD.open(filename);// Abrimos o arquivo que foi solicitado
if(!myFile) Serial.println("file open failed");
edit: The funny y = ÿ = 255 = -1 = fail.