Protecting Inputs in Digital Electronics

Talks about microcontrollers, long wiring, and even high voltage (without defining what is considered "high", afaict) in the context of industrial environments.

Without even mentioning optical isolation?!? (optical fibers for transferring signals, optocouplers on inputs MIDI style). Or another option: isolation using magnetics (signal transformers etc, or even relais for slow-moving on/off signals). Not to mention wireless options that aren't always a good idea, but sometimes are.

The article itself looks written by a knowledgeable person. But personally, because of the above, I'm struggling to take it seriously... hit Wikipedia or head elsewhere for better ideas.

Btw: the article is not wrong! But I'd consider the methods described mostly at circuit board level (peripherals <-> controller on the same board, or between boards sitting next to each other). Head out of the electronics' cabinet, bring in more solid protection measures.

A $0.30 optocoupler easily gives you >4 kiloV of electrical isolation. Nice to have when a damaged 230V AC cable hits a signal wire.

And saves your control electronics when lightning strikes nearby (direct lightning strike -> all bets are off ;-)

Useful in protecting GPIO input pins of a MCU.