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.
The support hotline will ask you to hold your phone towards the device. It is less error-prone (than a human) and contains more info than a blink code. I find it really clever.
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.
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.
Whenever someone brings up washing machines and software, I am always reminded of Forth[0]:
As an example, imagine a microprocessor-controlled washing
machine programmed in Forth. The ultimate command in your
example is named WASHER. Here is the definition of WASHER,
as written in Forth:
: WASHER WASH SPIN RINSE SPIN ;
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.
[1] https://github.com/kabelincho/LG-Smart-Diagnostics-modem
Do you mean by mimicking the noises themselves?
We have a Miele washing machine and a Miele dryer. Solid machines all around even after years of use.
https://en.wikipedia.org/wiki/IEC_62056