Trouble with printing through SD card

[Nazulle]

Since I bought my printer, any time i wanted to print something I would have to take my computer with me to where I have my printer and leave it there for few hours it would be working. I grew tired of doing this mainly because school started and I need my computer for it (I don't want to work while I'm near the printer because of noise and ABS fumes). So, I decided to try printing through the SD card.

I would open up MatterControl, load the stl file, then save it to my SD card as a .GCODE file. The problem appears once i plug the SD card onto the printer in which when I try to load up the file, my printer would just beep and go back to the home screen (where the temps are displayed). What am i doing wrong? Is it a problem with Mattercontrol or is it something I did incorrectly?
Thanks

P.S: I still consider myself relatively new to 3D printing so sorry if this is a dumb question to ask.

[lightninjay]

There are two possibilities here, in my opinion.

1) The file is not being written properly to the SD card and you are trying to start a corrupted gcode file, which the printer will often reject by just flashing a printing confirmation and then acting as if it has finished the print.

2) Your printer was not currently at the temperatures required to begin printing by the Gcode, so your printer merely homed and was waiting for the temps to rise. If this is the case, you can preheat your printer to the specified temps you used in Mattercontrol when saving the file, then attempt to print the file from the SD card, and the printer should begin printing.