If you had to choose between SPI and I2C on a single board, which one would it be?
I'd use SPI if I had one or two chips and only needed simple transfers of data from one internal register. Use I2C if you have a chip such as the Analog Devices AD7991, which has several registers to set operating modes. I2C is the only way to connect to it. Look for the external devices you need first and let them govern the type of MCU interface you need. --Jon
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This discussion will examine what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.