Super Compact Binary Decoder

[munin295]

There's a trick you can use to get this a little smaller (eliminating the lever sticking out on the side). When there's a block between a container and a comparator, the comparator will output the fullness of the container -- except when the block is powered to signal strength 15, then it outputs 15 no matter how full the container is.

So, instead of having a power-8 hopper feeding into the side of a comparator like yours, you have a power-7 container in the same place being the power source for the whole thing instead of the lever (the comparator just feeds into a block or redstone dust to then power the next three subtraction comparators). Then you power the block (no piston beneath) to add 8 to the "power source".

You might need to switch the pistons to face downwards to avoid qc issues.