What a coincidence, I converted "DAD" hexadecimal to the equivalent "3501" decimal. Happy Father's Day!
Building off my last circuit (https://everycircuit.com/circuit/6109219316826112), I chained a few more Double-Dabble circuits together to get a 12-bit hexadecimal to decimal or binary to BCD converter. For a tutorial on how to Double-Dabble (aka shift add three) algorithm works, check out my simpler 4-bit circuit: https://everycircuit.com/circuit/6548980953251840
It's a little slow, so be patient. The hex number is immediately shown on the left 7-segment displays. Wait for the clock (green waveform) to pulse 12 times for the 12 bits (blue waveform). There will then be a pause as the decimal number is displayed on the right four 7-segment displays. Then it will reset (orange waveform) to take a new reading.
To ensure accurate readings, stop the simulation when you enter a different hex number on the logic buttons and restart the simulation. If you change the hex number as it is running, you need to wait until it resets and read the number in from the beginning.
