LIST FILES:
demo0.txt
demo1.txt
demo2.txt
...
..
how to open a different file every 1 second?
int N=0;
void loop(){
myFile = SD.open("/data/demo"+N+".txt");
if(time - timA>1000) N++;
}
how to open a different file every 1 second?
Put the filenames into an array either by typing them into the program or reading them from the SD card and putting them in an array in the setup() function.
Each time you open a file save millis() in a variable.
Each time through loop() check whether millis() minus the time opened is equal to or greater than 1000
If false, do nothing.
If true then get the next filename from the array, open it and save millis() again.
If the array index becomes larger than the number of files reset it to zero.
Questions
What will you be doing with the file once open ?
When do you intend to close the file ?