I've procured a seven segment, eight-digit, common-anode display, and am somewhat at a loss as to how to drive it.
I understand that the MAX72xx will drive common-cathode displays--is there an equivalent for common-anode parts?
(For whatever it's worth, what I have is the front panel from an Omron ETR-9090 industrial temperature control. It has a flat-flex cable that connects to the body of the controller, and I'm almost done working out the pin assignments. There are also two LEDS--one red and one green--and four tactile pushbuttons that I can't figure out.)
the Phillips SAA1064 can drive 4 CommonAnode 7Segement-Display using the IIC- or I²C- or TWI-Bus. You should be able to use this driver with the Wire-Library of the Arduino.
I will admit, though, that I was hoping for a cheaper solution (involving some 74HC595s or something similar, perhaps) that I might have on hand.
The MAX7219 and the Phillips-IC do the whole multiplexing in hardware.
You could actually do that also with some shift-registers but then the ATMega has to do the multiplexing in software. The question is : what is left of your internal RAM and processing power when you have to implement multiplexing. Some interrupt-timer-programming is required, but if you want to go for it here is a link to the LedMatrix Backpack from Sparkfun:
follow the schematic-link and you see they used an ATMega and some 595's for it.
But the processor is not doing much besides multiplexing the Leds. (sits and waits for data on the SPI- bus most of the time)