Time for a bit more soldering, I think. I couple of months ago I bought a little MAX7219 LED array kit from ebay for a couple of pounds. They are all over ebay and aliexpress.

As kits go it is very simple – a resistor, two capacitors, some sockets and some optional connectors. Soldering it was pretty easy. The only things I needed to be careful about were leaving enough “leg” showing on the electrolytic capacitor so that I could bend it down to avoid fouling the LED matrix module and making sure the sockets for the LED module were nice and straight. The “pins” on the module are really just bits of wire sticking out of some epoxy, so they need to be carefully aligned with the sockets to avoid bending.

As for what to do with it I’m not too sure. Although the pins are not labelled in the same terms, I’m pretty confident that the interface is SPI. I guess I’m going to have to work out how to drive SPI devices!