Hello Fizzle. I have to agree that automatic feeders are not the way to go. One's I purchased in the past always clogged. Your fish should be fine without food on Saturday and Sunday and then you can feed them when you get home on Monday.
Peas act as a laxative and are high in protein. It may take a time or two feeding them the peas before they realize that it's food. If you have time before you leave you may want to consider a
water change/vacuum to remove all the access food in the substrate so that you don't get an
ammonia spike. Use fresh or frozen peas and not canned peas that contain salt. Blanch them or heat them up for a minute to soften them a bit. Slice them in half and remove the skin. Then you can slice them to about the size of the fishes eye. (as their stomach is about as big as one of their eyes).
Travel safely and try not to worry too much.
Keep us posted.
Ken