For his Hackaday Prize entry, [castvee8] is making seven-segment displays out of vintage neon ... cycle through the numbers 1 to 4. The actual code to do this is running on a microcontroller ...

seven-segment display (Image courtesy of LXD, Inc.) In their natural state, liquid crystals line up with the orientation "rubbed" into the front and rear glass panels. The rubbings are microscopic ...

Some vendors make I2C controllable seven segment displays, but they cost about $10 ... similar purpose which could easily be adapted. The code implements a software I2C slave, which reads data ...