Devices! Devices! Devices!
By Mark Hermeling
That is what embedded systems is all about: handling devices. An embedded software system has input devices and output devices and some amount of software running on operating systems, running on hardware that turn input into output. The trick is to handle the input in a fast an deterministic way and generate output in a fast and deterministic way. Determinism is important all the way through the system, from the device, to the hardware, to the operating system to the software running on the operating system.