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Hacking my “smart” toothbrush

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Re: Hacking my “smart” toothbrush

#301

Post by Kirby64 »

willyt wrote: post #300
Kirby64 wrote: post #266

Earlier quoted context omitted.

Nobody would attach the timer to the actual moving drum, so the worst it has to deal with is physical vibrations from use (which, admittedly, can be quite violent if you have an unbalanced load). There are very few digital circuits that are actually meaningfully sensitive to vibrations. At worst, it's a manufacturing problem to make sure the PCB/solder joints don't crack from vibration. In comparison, the mechanical…

In a fridge the typical failing part is the plastic shelves in the door. The compressor almost never fails and discarded fridges are a great source of cheap pumps if you need to scavenge them. Source: The episode of 'The Secret Life of Machines' on fridges. Search it on YouTube.

Maybe for certain models. Personally I've never had a shelf break on any fridge I've used, which makes it sound like that's a user error to me.

On the compressors, there was a vast swath of Samsung and LG fridges that had known defects on compressors causing them to fail. Right now, the ice machines are probably most problematic. If you own a Samsung fridge with an ice maker you know what I mean.

Re: Hacking my “smart” toothbrush

#302

Post by SV_BubbleTime »

maratc wrote: post #168
SV_BubbleTime wrote: post #42

Earlier quoted context omitted.

It can’t be far off that they ship a BLE or Wifi enabled Sonicare that reports your best brushing habits to the app that then posts it on Facebook for philipPoints you compete with your friends on… oh shit… what have I done!? Anyhow, blocking unofficial heads is just an OTA firmware update away.

There are no "OTA firmware updates" for Sonicare toothbrushes. There are no other firmware updates either.

Yet. That was the entire point of my post.

Also, how would you know? I have an IOT product that can delta OTA, so only the bytes of the firmware that change are sent to the device, I can do firmware updates that are crazy fast. ESP if it’s just something like turning a feature on.

Re: Hacking my “smart” toothbrush

#303

Post by shard »

error503 wrote: post #272
JadeNB wrote: post #270

Earlier quoted context omitted.

I'm willing to believe that the best electronic switches can last longer than the best mechanical switches, but there's so many more ways for an electronic switch to fail that it's a lot easier for me to trust an off-the-shelf mechanical switch than an off-the-shelf electronic one, especially if the cost of failure of the mechanical switch is just an easy swap in of another one.

In what ways can a purely electronic, no moving parts, switch fail? There are so many different mechanical things that can break, jam, get gummed up...

Capacitors can die, for example. Anything with a battery backup, the battery can leak and damage components. Electronics are more prone to ESD and water damage than mechanical parts.

Going into the realm of unlikely scenarios, electronics are more susceptible to EMPs.

Re: Hacking my “smart” toothbrush

#304

Post by midoridensha »

gonehome wrote: post #296
Kirby64 wrote: post #252

Earlier quoted context omitted.

Mechanical timers are fine, but digital circuitry is by far going to be more reliable if designed properly. There isn't anything physically moving, so the failure modes are much more restrictive. Also, digital provides advantages with offering variable timing on a dryer, for instance, based on the input of a moisture sensor. Mechanical methods for that are more complicated. Additionally, I would be very surprised if…

Yeah, I’m always skeptical of “it was better in the old days” type arguments (even though I recognize the aesthetic appeal of analog). People make similar claims about cars, but old cars broke down all the time and new ones are basically appliances that “just work” without the driver needing to know anything. Similar for computers to smart phones (though obviously both digital in that transition)

Back in the "good old days", a car was ready for the junk heap after 50k miles. These days, that's barely broken-in. "But you could fix it yourself!" Who cares when the thing has such a short lifespan? It's really strange hearing people pining for the days of shitty old cars that you needed to constantly adjust the carb, set the points, etc. Insane.

Re: Hacking my “smart” toothbrush

#306

Post by EdwardDiego »

Kirby64 wrote: post #301
willyt wrote: post #300

Earlier quoted context omitted.

In a fridge the typical failing part is the plastic shelves in the door. The compressor almost never fails and discarded fridges are a great source of cheap pumps if you need to scavenge them. Source: The episode of 'The Secret Life of Machines' on fridges. Search it on YouTube.

Maybe for certain models. Personally I've never had a shelf break on any fridge I've used, which makes it sound like that's a user error to me. On the compressors, there was a vast swath of Samsung and LG fridges that had known defects on compressors causing them to fail. Right now, the ice machines are probably most problematic. If you own a Samsung fridge with an ice maker you know what I mean.

On the Samsung fridge aspect...

A few years ago I was renting a house that came with a Samsung fridge that provided chilled water / ice. My kids loved the chilled water.

However, our usage of it caused the paint to start bubbling below the dispenser, and the owners of the rental wanted me to replace the door at a cost of ~$800 USD(!).

I argued that we were using the fridge as designed, so we weren't liable, instead they should discuss what looked to me like an obvious design flaw with Samsung.

They disagreed, so we ended up in court. My defence was about 12 pages printed from an appliance review site of people specifically complaining about this paint bubbling.

Easiest win ever, but seriously, how do you put a device that works with water into a fridge and fail to ensure it can't leak under the paintwork?

Re: Hacking my “smart” toothbrush

#307

Post by beezlewax »

nuancebydefault wrote: post #205
tzs wrote: post #193

Earlier quoted context omitted.

This has long been a temptation for engineers. 40 years ago the textbook in the digital electronics class I took at Caltech had a chapter called "The Engineer as Dope Pusher" that talked about it. It gave as an example clothes dryers. The way most home clothes dryers working back then was you put the clothes in, you turn a dial on a timer to the number of minutes you want the dryer to run, and you press start. The me…

What do you mean by "reliable" wrt mechanical timers? I'm pretty sure the clothing dryer is a harsh environment for such a component (moisture and heat can easily cause corrosion and mechanical stress). Also, I guess timing gets less accurate over time. If there are rubbers preventing moisture from entering and oil from leaving, those rubbers will wear out.

I have one that is like 40 years old. The heating element is similar to those in an oven.

The only things that broke are plastic door hinges.

Re: Hacking my “smart” toothbrush

#308

Post by tzs »

gonehome wrote: post #296
Kirby64 wrote: post #252

Earlier quoted context omitted.

Mechanical timers are fine, but digital circuitry is by far going to be more reliable if designed properly. There isn't anything physically moving, so the failure modes are much more restrictive. Also, digital provides advantages with offering variable timing on a dryer, for instance, based on the input of a moisture sensor. Mechanical methods for that are more complicated. Additionally, I would be very surprised if…

Yeah, I’m always skeptical of “it was better in the old days” type arguments (even though I recognize the aesthetic appeal of analog). People make similar claims about cars, but old cars broke down all the time and new ones are basically appliances that “just work” without the driver needing to know anything. Similar for computers to smart phones (though obviously both digital in that transition)

It wasn’t the old days. At the time the book was written and at the time I took the class mechanical timers in dryers were ubiquitous. Digital was new, expensive, and didn’t offer any advantages for that application.

Eventually digital became cheap, and enabled new features like dryers that had various sensors that could be used to optimize drying, but that was several years down the road.

Re: Hacking my “smart” toothbrush

#309

Post by gwbas1c »

fire wrote: post #291
gwbas1c wrote: post #176

Earlier quoted context omitted.

I bought one of these toothbrushes almost two years ago. It really makes a difference: - The connection to my phone helps coach me in making sure I'm brushing my teeth properly. Bad habits sink in easily, and my various dentists all point out that my teeth and gums are much, much healthier. Given that I am cursed with some bad oral genetics, it's "money well spent" for me. - The counter helps remind me when to change…

ironically the special blue bristles in the philips heads that turn white when the brush head needs to be replaced is exactly what you want, I think?

That's not the same, because it's gradual, as opposed to a beep / notification.

When things change gradually, I tend to ignore the change.

To put it in a different context, I've had the fadeout brush heads for years, but I had to get in the habit of changing my brush head when I went in for a dental cleaning because otherwise, I'd just keep using it forever.

Re: Hacking my “smart” toothbrush

#310

Post by josephcsible »

luma wrote: post #242
josephcsible wrote: post #218

Earlier quoted context omitted.

> You're saying that a microcontroller should never have a certain feature because you don't like how it has been implemented by a single company. It's not the implementation. I don't want hardware to ever be able to permanently make itself less useful, no matter how it's done or what it's being used for.

You're making an argument that PROM, WORM, efuses, etc all shouldn't be allowed to exist. They're used for all sorts of features, not just security. You might do well to apply the lesson of Chesterton's Fence before you call for a ban on things you don't actually understand.

For legitimate cases of write-once media, it should be legal if and only if it's separate from the rest of the device and easily replaceable (e.g., a socketed chip or a DVD+R). Anywhere that write-once media is permanently attached to something else, it inevitably ends up being used for evil.
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