Vacuum flourescent displays are a beautiful piece of retro technology. Noritake Itron and a few others still build them as dot-matrix or full graphic displays. But the technology dates back to the 70’s and you can find some surplus units available on eBay.
...To keep things short: I’ve had an Anet A8
3D printer for a while now and wanted to flash an updated version of its
Marlin firmware.
For some reason however, the bootloader was broken. So I couldn’t flash it with
avrdude by simply using a USB cable. For this case you can find lots of
tutorials on how to flash Arduino boards with a second Arduino. I didn’t have a
second Arduino at the time though … so why not just bit-bang it from a Raspberry
Pi instead?