Here's a series of Digital Dice Towers based on the Heathkit HD-16 Code Oscillator. This kit was available from Heathkit from the late 60's until the mid 70's. It's a battery powered buzzer and speaker in a sheet metal case. HAM radio operators would connect it their morse code key switch to practice.

The HD-16 case is a nice compact size with an excellent speaker. So, I decided to built a series of Digital Dice Towers based on this excellent period case.

The first piece utilizes a nixie tube display and is based on the software and hardware for the revised design for the 1975 Bell & Howell IMD-202 digital multimeters. So, it packs a custom 170 volt power supply, CPU board, amplifier, rotary encoders, roll button, indicator LEDs, and power switch in the little case. The nixies and the 7441 decoders/drivers were harvested from one of my spare Bell & Howell digital multimeters.

The sockets and drivers were hand wired to a protoboard.

Fitting everything into the case was a bit of a challenge.

The bubble seven segment display piece was just as complicated. However the audio only version was noticeably easier to build.

See the files attached to this project for the source files for these digital dice towers. The zip files include all the source and the Atmel Studio project files. Comments in main.c document the pinout on the ATMega 328p processor.

Here's a video demonstrating the operation of all three pieces in this series.