For example, what programming language and/or software would be used to control an automated sprinkler system, or other automated device? I want to know how the software interacts with the machine.
Usually industrial computers us logic programming. A PLC, ie, Progrmmable Logic Controller, is used in many automation uses. They use logic to make decisions.
It all depends. Usually assembly. But no hard and fast rule.
I developed some machine programs many years ago. We used Intel 8080 or Zilog Z80 CPUs. The board was designed with the appropriate support chips, device driver interface and RAM/ROM suitable for the project. We developed the program in assembly language. The typical program goes like this. At power on, self-diagnostics was run. Then the program initialized by setting up the programmable chips and defining constants. Next, the program enters into 'run' mode where it constantly monitors inputs for any changes and the program is made to react accordingly (ring an alarm, turn on a sprinkler, etc.).
