This decimal to binary converter is the same as what I used for my item request system on a server. I will eventually get to building and posting that on my own world but for now here is my system.

When you spawn you should be in a room where you will see four levers. These levers are the bits and on or off is indicated by the redstone lamp above them. When you enter a binary number then you will see the redstone lamp on the side light up with what number has been selected in decimal and binary.

This can go from 0-15 (4 bit) however the design can be made bigger like I plan to do for my item request system on a survival server.
PLEASE NOTE: THE REDSTONE LAMPS FOR THE NUMBERS CAN TAKE A MINUTE TO LIGHT UP BECAUSE OF HOW CLOSE TO EACH OTHER THEY ARE AND BECAUSE I DIDN'T USE COMMAND BLOCKS SO REPEATERS WERE USED.