automatic watering

Hey guys. I was wondering if any of u know how to automate watering down to the point where u can choose how many ml or liters u want to water each time? im growing in a small 2x2 box with 2 autoflower in 11L fabric pots. I can only water the plants in the weekends (Because of work), which...

What do I need to do to use GH drip rings. Like some 5 gal bubble buckets, a pump and timers. Who can give me a detailed low down on a simple system for this. I'm thinking 2 systems min for Bloom and Veg feeding. I'm sick of mixing shit everyday!