SD printing

Hi
I added an LCD controller to my prusa i3 , running marlin firmware.

I didn't understand if it will allow me printing without connecting my printer to the PC at all, using pronterface I can upload files to the SD card and print using the SD card. is there anyway to upload the file using my PC card reader then putting the card into the printer and make it print the file?
the rotary endocer doesn't do anything to the printer. why am I supposed to do with it?
sorry for asking such questions I didn't find a good source of information.
UPDATE
I had to choose the right marlin configuration, simply uncomment : #define REPRAP_DISCOUNT_SMART_CONTROLLER
it is works fine now, I just put the gcode file straight from my PC to the SD card and print? do I need to change the name/extension of the file?
Morad

Edited 1 time(s). Last edit at 07/19/2014 11:13AM by EEstudent.

You can put your SD card into your computer and then move the card to the card reader on the control panel and print without the PC. You won't be able to graphically follow the print. Also, I think there are some naming restrictions. I usually put an extension of ".g" on the file and it works.

The problem is that you're not going to be able to print from the SD card without the PC unless you figure out what's going on with your encoder. While on the main screen, the encoder should increase and decrease your print feed rate multiple (M220 I believe). If you click the encoder, it takes you into a menu where you can, among other things, navigate your SD card and choose a file to print. The menu also allows you a somewhat clumbsy control over the printer allowing you to do things like move the axes, heat up the hot ends and bed, etc.

Thanks.
I haven't tried printing using the SD card yet but I was able to see all firmware setting, controlling axis, heating the bed/hot end and basic things.
I also can see all the files/folder on the SD card but didn't try to print any thing, the file uploaded using pronterface had G extension and names converted to capital letters (NAME.G).
I have used 16GB sandisc SDHC card formatted to FAT32, what other types will it support? I want to buy cheap SD card because what I have is for my DSLR (extreme edition)
I will buy cheap SD card of 2/4GB and update the post.

I don't know other supported formats, but fat32 is supported in windows and Linux. I used to print to the card, but it took too long. I just put the card into my PC and use the Linux command line to copy files there.

Admittedly I don't do this much, but I've never had an issue once I figured out the naming convention.

what is the name convention you use?

As I mentioned before, just make the extension ".g". The rest of the file name is up to you.

I usually don't bother with directories because I only use the SD card as a temporary measure. Rarely do I store files there "permanently"

When uploading files from Repetier, it always requires an old DOS 8.3 name also. Not sure if it's the same when copying from the PC, but the display seems to only support 8 char for the filename, 3 char for the extension. And I think .gcd will also work as an extension.

Bruce

update
I bought sandisk 4GB SDHC card class 4, formatted it as using FAT (not FAT32).
I just copied the gcode file from my PC to the card directly without changing the name of the file (file name = PageHolder-fixed.gcode).
it worked fine