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?
> 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.
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.
There are lots of examples on YouTube, this one seems succinct: https://youtube.com/shorts/3Eb315vL9uw . They picked good tones to make it satisfying IMO. I don’t know of anyone who’s reversed the bitstream in public, though, but it doesn’t seem like it should be very hard.
That's a great example, thanks! I was looking for "LG Smart Diagnostics" and "audio" and then "LG Acoustic Diagnostics" and found TVs calibrating their audio playback but not this. Trying "LG Audible Diagnosis" found a bunch like yours.
That's some advanced gatekeeping right there. Where other appliances might have a blink code or several digit error display (Miele) to look up in a manual, the phone method tires you to the manufacturer.
TL:DR; the circuitry could be powered by 5V, but to save costs that 5V is 5V difference to 110/220V, not 0V (earth). Connecting a computer would create a 110/220V difference between the ground of the machine's circuitry and the computer's...
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?
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.
Do you mean by mimicking the noises themselves?
[1] https://github.com/kabelincho/LG-Smart-Diagnostics-modem
https://gemini.google.com/share/8da7ecf202d8
TL:DR; the circuitry could be powered by 5V, but to save costs that 5V is 5V difference to 110/220V, not 0V (earth). Connecting a computer would create a 110/220V difference between the ground of the machine's circuitry and the computer's...