The aesthetic we were going for was more Apollo Guidance Computer, so 7-segment LEDs were perfect. It turned out to also be a great design choice software-wise because the entire rocket originally ran on an atmega328 which had only 2k of RAM; there really wasn't much room for frame buffers. But the state of a 7 segment digit (plus one decimal point) fits perfectly into one byte, so the entire rocket, which was originally 14 8-digit rows, needed only 112 bytes of frame buffer.
By about 2012 we wanted to write more complex software, so I made new revision of the main controller that took an atmega1284, which has a lot more RAM (16K, vs 2K) and program space (128K, vs 32K).
The big retrofit in 2019 went to a 32-bit STM32 which had a hardware floating point unit, making it possible to do fancier animations. The rocket now supports the classic "snake" game.
The aesthetic we were going for was more Apollo Guidance Computer, so 7-segment LEDs were perfect. It turned out to also be a great design choice software-wise because the entire rocket originally ran on an atmega328 which had only 2k of RAM; there really wasn't much room for frame buffers. But the state of a 7 segment digit (plus one decimal point) fits perfectly into one byte, so the entire rocket, which was originally 14 8-digit rows, needed only 112 bytes of frame buffer.
By about 2012 we wanted to write more complex software, so I made new revision of the main controller that took an atmega1284, which has a lot more RAM (16K, vs 2K) and program space (128K, vs 32K).
The big retrofit in 2019 went to a 32-bit STM32 which had a hardware floating point unit, making it possible to do fancier animations. The rocket now supports the classic "snake" game.
But still just 7-seg LEDs :)