Hey guys I want to port sprites I made on the computer. I heard that you can use Petit Modem. Any tips?

It's probably easier to just manually copy over the sprites, specially with editors like Th. GRP Editor.

Well I have A LOT of sprites to copy. Is there an better program for it?

My advice for Petit Modem is to put the 3DS in a quiet place, turn off any devices that could make a sound, plug in headphones and set them beside the 3DS Mic, and then start. While it's transferring, you should leave the room and close the door, then play a game for 3 minutes.

or if you have removable cord on headphone side, simply plug that in to the 3ds and dont worry about noise.