Dublin cheapish Lunches/Dinners

Hi,
Figured it'd be best to post it here. I'm a trinity student and I'm going to be in Cabra for the year, near the North Circular Road. By some miracle I got a room in a house but I will have access only to that room, which would have very basic facilities, basically a microwave and a kettle. That's fine and I can do some improvisation for around 3-4 days of the week but I'd have to grab some grub in town at some point. The campus places are alright but they close earlyish and I often stay in the library until late.

Basically, I'm looking for decent cafes/restaurants in the city centre and Cabra. Not too dear, just something simple like a soup/meal and a drink.

Thanks for any advice.