We have seen a few cool waterfall displays before but this 96 Solenoid Waterfall Display (Google translated) is the first total DIY one I have seen. There isn’t very much technical details available but from the short writeup there is enough information for inspiration. I can just imagine how much this display would have cost if the solenoids weren’t found at a scrap yard.
“Each of the 3 solenoid valve blocks has assembled a board with shift registers and MOSFET arrays to drive the solenoid valves. A master-AVR pushes the data via SPI to the shift register and thus controls the various valves. The patterns are stored on an EEPROM and can be changed via UART.”
