[landr0id]

Pretty cool for BSH and Miele to hop on a call with the researchers just to make sure there were no issues they were unaware of. Sounded like it was productive and positive for everyone involved. Hopefully they don't start doubling down on hardware security though :p

The optical communication for the Miele was pretty interesting too. I'm assuming it's to prevent moisture from corroding a port of some kind. Does anyone know of other devices this is used in or other benefits to this?

[opello]

> I'm assuming it's to prevent moisture from corroding a port of some kind.

The primary value discussed in the talk was electrical isolation since there's mains voltage in the appliance and the potential for shorts or inadequate isolation would require some kind of isolation, so a path that optically isolates the communication makes quite a bit of sense.

I'm also curious if other devices have gone this route.

[bri3d]

LG appliances at least used to use acoustic signaling for diagnostics: hold a phone up and the washer makes some modem-esque (I think it’s 4-tone / 4-FSK) noises and the app or technician can diagnose issues. It was originally engineered to even work over voice codecs, so a customer without a smartphone could relay the diagnostic session to a technician.

[mjochim]

Electric meters often blink a signal LED for every X kWh, so other devices can read the signal. I'm not sure if this is used for bidirectional communications, though.

[eru]

Alternatively, I guess you could also use really thin cables to carry the low voltage paths; and that act as fuses, if ever a lot of current at high voltage was flowing across them? But probably not very reliable both in regular operation and as fuses.

We have a Miele washing machine and a Miele dryer. Solid machines all around even after years of use.

[MisterTea]

> The optical communication for the Miele was pretty interesting too. I'm assuming it's to prevent moisture from corroding a port of some kind.

IRDA was very popular at one point and still lives on in applications like these. It's an IR serial port hung off a UART. It's stupid simple requiring no cables, pairing, or complex protocol stacks. Some smart phones have IR blasters built in so its a total win for ease of deployment in cases like these.