Minecraft. I got it in May, didn't really start playing it until about June, didn't start messing with Redstone until about a month ago, and didn't start getting into more complicated Redstone until about 2 weeks ago. Now I'm working on a digital clock.
I've built the display, the decoders, and the hours counter, so all that's left is the minutes counter and the clock generator.
The display. I decided I wanted to make a clock entirely out of wood in the middle of a forest. The display uses pine and oak logs, and all other structures are built using wood planks.
Behind the display. For the minutes, each digit has its own 7-segment decoder and each will have its own counter. For the hours, there's only one 9-segment decoder hooked up to one counter. I decided this would be easier than making two decoders, since the tens digit in the hours only ever makes a 1, and it's only used for 3 hours. The other segments in the tens place are always inactive.
The hours counter underneath the hours decoder. Originally I used a relatively simple counter which used a minecart track, but I soon got really frustrated because animals kept jumping on the track and in the cart, which would fuck up the count and it would take forever to fix it. It took a while to figure out, but I came up with this counter which uses pistons. Each time it receives a pulse, either one piston turns on, or if all of the pistons are on, all of them turn off. By receiving a pulse every hour, the counter cycles through 12 states every 12 hours, with each state corresponding to which number is displayed. It's much more reliable and much easier to reset if it does somehow screw up.
This has been a really fun project, and it makes me wish I'd gotten into digital circuitry sooner.
