A minimalist 130x74mm Numbers Only Enigma Z30 Machine Simulator using an ATMega 328 powered Arduino Nano and a custom PCB
Started to solder both enigmas.
What's wrong with this picture?
The answer and more pictures here:
Head over to the Mega Enigma Simulator project to see them:
Here is the pin assignment for the Z30. Fundamentally it is the same circuit in the Mega Enigma, just smaller.
To understand how this will be illuminated and read, see the following log on the Mega Enigma project page:
Here we go again:
Here is an almost finished design, all it needs it a little tweaking of the bottom silkscreen. Time to add a USB label indicating which way the Arduino Nano is supposed to go.
The footprint for the Nano has been placed with the USB connector facing towards the LED displays. While this design will technically work, the USB port is concealed.
Time for a quick re-design:
Now the USB connector is facing left. Notice the location of the VIN pin, fed from the power switch. The cost of this redesign was two more horizontal traces in the front to get power to the right location now that is away from the power switch.
Time to check all the connections carefully.
Witness the importance of double checking wiring. The menu key (above the 0, is wired to the same select/return line combination as the 0 key (bottom of image). Luckily, another return line passes by and is just a matter of switching the bottom of the pushbutton to a different return line.
By simply connecting the bottom of the key to another return line, the menu key now has a unique select/return line combination.
Since these circuits are wired without using a schematic, very careful checking is needed at the end to make sure everything is wired correctly.
This is the Z30, a charmingly weird Enigma Machine capable of encrypting only numbers.
I have been considering how to make a PCB version of the Z30 for a while. Here is an earlier layout.
And the same layout with tilted buttons, inspired by the hackaday supercon badge.
Designing the Mega Enigma got me thinking about display and keyboard circuits. Version 2 was designed to use components already on hand from the Sinclair Scientific and Art Installation projects The only thing that needs to be ordered is the board (approx $13 for 5).
The first things to be connected were the display segments to a horizontal bus bar. The lamps and keys were separated into return lines with no more than 8 devices each.
Little by little, the design started taking shape (always do the hardest connections first) and 3 hours after starting to lay copper down, all the connections were finalized.
This design passes DRC and amuzingly it was wired only using the default 24 mil traces. Next step is to map the pins to the devices they connect.