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•1h ago
> 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•1h ago
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.
opello•55m ago
That's pretty cool. I found a write-up[1] on it but unfortunately didn't come across any examples of the communication.
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.
opello•33m ago
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.
imglorp•53m ago
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.
landr0id•39m ago
>so a customer without a smartphone could relay the diagnostic session to a technician
Do you mean by mimicking the noises themselves?
wpm•31m ago
No you see you just need to buy specially marked boxes of Cap'n Crunch that have a plastic whistle in them that plays the tones for you.
mjochim•21m ago
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.
landr0id•1h ago
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•1h ago
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•1h ago
opello•55m ago
[1] https://github.com/kabelincho/LG-Smart-Diagnostics-modem
bri3d•51m ago
opello•33m ago
imglorp•53m ago
landr0id•39m ago
Do you mean by mimicking the noises themselves?
wpm•31m ago
mjochim•21m ago