Arduinos are cool, but...
Back with more digits! A few days ago I posted about a digital I/O expander I was monkeying with for work, and posted an Arduino sketch I used to wring it out. That's all fine and good, and I did learn how to drive the chip around and accomplish my real goal, learning how to use the interrupt on change function. But, when it comes to work, we won't have an Arduino in our product. What we will have is essentially a PC; the computer part of it is a Com Express (Type 10) System-on-Module. While extremely flexible and reasonably priced (and available in industrial temperature range, this thing can actually operate at -40C), it doesn't have a SPI bus. So why did I pick a SPI bus? Well, the answer is long and to steal an expression from the t-shirt I wear to work on Fridays now, I don't have the time or the crayons to explain it to you. We have another, much more expensive I/O bus we also have to attach to, and the most sensible and affordable driver chips for tha
