The MAX7219 chip uses a simple serial protocol at any speed up to 10MHz. This C code implements the protocol for the Raspberry Pico. It can update an 8-character display at several kHz. Rewriting it to use the Pico’s PIO should make it much faster - the MAX7219 should be able to update at 62 KHz. Of course, this is far faster than human perception, but offloading the bit-banging to the PIO would let the processor handle real-time tasks better.

Our garden in 2020: Snow peas I started these early, spread out daily over a month. They did well for a while, but were badly damaged by heat before they finished producing. This was an unusually hot and dry year. Melons planted near them as they matured did not do well. Melons Two varieties, both started indoors, then transplanted to the greenhouse and clipped to strings to grow vertically. We lost a few to grubs, but protected most with cardboard collars.

I am rebuilding this website using hugo. So far it seems like a well-designed system, though I haven’t pushed its limits for site stucture or appearance yet.