Analog Awesomeness
It's easy to run out of analog pins on your Arduino far too soon when you are working on a project. Add a multiplexer or two, though, and you're back in business.
Reading and writing from an analog multiplexer
Lead Image © Oleksiy Tsuper, 123RF.com
Analog Multiplexer
In a previous article on how to hack the Robosapien [1], I showed how a digital multiplexer, such as the MCP23017, could help you out. The limitation was that, although you could control several DC motors from a couple of pins (no mean feat) and you could have them change direction on the fly by adding H-bridges, you could not control the speed or use the multiplexer to read in analog input, such as from temperature sensors, light sensors, and so on.
Plenty of analog multiplexing shields are available out there, but it is cheaper and more fun to use the chips themselves. You get to learn the ins and outs (literally) of the Integrated Chip (IC). This knowledge can come in handy for projects in which a shield simply won't do because of cost or space constraints.
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