This week I worked on completing the layout of our PCB and ordering all of our parts. We ordered the rotary encoders, MAX7219 7-Segment Display, SD Card readers, and sourced the remaining miscellaneous parts (Micro SD cards, adapters, buttons, LEDs) . Due to a shortage in stock we could only order 2 rotary encoder instead of 3 so we updated our design to only include 1 rotary encoder.
Nancy and I reorganized our PCB layout to be much cleaner, more historically accurate and updated power considerations. We updated the layout of our PCB to be historically accurate to the actual Enigma machine’s lampboard (different from the standard qwerty keyboard – attached). We also adjusted spacing for 10 mil traces as a safety precaution, updated our button footprint with the new tactile button we settled on and changed the layout to float above the FPGA at a diagonal so the onboard buttons and 7-segment display can be accessed as a fallback option. The in progress PCB layout is attached below.
I worked with Amelia a little on the logic of our PS/2 protocol that she wrote and also worked on finding the solution to a setback when our current PS/2 keyboard didn’t work with the power supplied from the FPGA. Nancy and I are planning to mitigate this potential setback with the SD Card reader by testing the required power level for a measurement to be read. Accordingly, we can build in a voltage regulator to our PCB so we don’t have power issues during integration.
This week I will order remaining small parts including 100 Ohm resistors and right angled header pins. I also plan to finalize PCB layout with updated power considerations, finish the traces and add silk screen labelling for user friendliness. Once PCB work is done, I will work on formatting and writing our MicroSD cards so they adhere to a format that is readable by our SD Card reader and hence our SPI protocol can accurately extract information.