gbernal:
This is my first post here, but I have been reading the forums for quite some time.
Then you know that you should post some code.
I'm trying to figure how to create a routine via software or hardware to stop my program from loading analog readings into my sd card.
I was thinking something like I press "A" key and stop or hardware I press a button and that stops it.
I haven't been able to find something close to what I want in my search, I don't know if I'm using the wrong words or what.
I can post the code if needed, but it's not much different from a datalogger from the SD library example.
You know enough to know how to read and debounce a button, right?
If not, have a look at Gammon Forum : Electronics : Microprocessors : Switches tutorial
You know what a if statement does, right?
If not, have a look at http://www.learncpp.com/
If there is some reason you cannot implement these things in your code, feel free to come back with some code you've tried, and we might be able to help.