I've made a home-made Arduino based on this video. The problem is that I can't upload anything, it doesn't react, only the LED double blinks in every second. What does that mean? How to fix it? Thanks.
It's a reasonably clear photo (another couple would help) however I do see at least one major problem. Pin 8 (and pin 22) are Ground, but I don't see any wires running to that. Also the 22 pF (or similar) capacitors connected to the crystal should have their other sides grounded.
I suggest you look at my page Breadboard Arduino which has clear photos and wiring guides. In particular:
Notice the ground wire, and how the capacitors are connected.
I suggest you double-check all wiring, and make sure it is very similar to this: