As embedded computers have become ubiquitous, so too the need for human machine interfaces has grown. Once found in only complex control systems, like distributed control systems in refineries and other process plants, HMI systems are now found in many guises and many locations, from games to industrial machines and tooling systems, with many stops in between.
HMIs have mutated and changed with new requirements, and they have become more flexible and capable. And while they've been doing that, theyve become smaller and more useful.
So what is an HMI anyway? Strictly speaking, any way for a human being to interface with a machine is an HMI. The touch-panel on your microwave is an HMI, the dial on your washing machine, and the cable remote-operated software selection guide on your TV is an HMI.