Why on Earth Does a Toothbrush Need a Microchip?!（原声文稿）

Well, would you look at that?

A toothbrush unlucky on a computer, I bet you didn't think you'd see that today, did you?

When I were a lad, toothbrushers were just plastic sticks with some bristles that you shoved in your mouth. But nowadays, it seems they're a little bit more sophisticated.

So I was looking at the brush head on my Philip's toothbrush, and I noticed this little brown dot, and a little bit of research I'd rely on revealed it was a microchip.

So what on earth is a microchip needed for on a toothbrush?

brush. So I have a really simple setup here.

I basically have a USB connection to an ESP32S3 that's this device here and that connects via I2C to the PN532 NFC reader so that's that little device here and you can see it's got this white band around the edge and that's its antenna so it operates at 13 .56 megahertz and it can read cards like this kind of thing And these little tags and of course these toothbrushes.

So I've written a little app to be able to read the card reader. It's dead simple.

It connects to the ESP32 by USB and then it uses the ESP32 to send commands to the card reader.

The clever thing about NFC is that the chip doesn't even need a battery.

When the card gets close, the reader generates a magnetic field that powers the chip.

The chip then subtly changes that magnetic field to send the information back. It's really quite clever.

The reader then decodes this, passes the data over an I2C link, back to the ESP32, sends the information back by USB.

So all this page does basically has a connect button and a read tag and that allows me to clear the data. so let's have a look at that.

So I'm going to connect to the card reader, I'm going to put it into read mode, so I'm going to hit read and I'm going to hold the tag over the top and as you saw on the ESP32 the green light lit up that's a successful read but you can see basically that this card it's just the blank card that came with the reader is blank not much on it just a few bits of hex.

Now let's do the same with the toothbrush.

So I'm holding it sort of vertically above the reader and I'm going to do a read tag.

Boom, look at that. All that information.

So all that information was stored on my toothbrush head. Can you believe it?

So the next thing is really to decode it.

So I'm going to be quite systematic about this.

I've got two brushes I've got the old brush I've been using for quite a while and I've got the new brush which has never been used.

So first up let's just see if there's a difference between those two.

I've actually got in my app a new tab called decode data.

This is actually going to decode that information from the toothbrush so I'm going to put the new toothbrush on now holding it over the sensor read brush so let's see what this is saying so record runtime zero it's a new brush lifetime look at that so it stores the actual usage it stores the actual intensity level on the toothbrush so my toothbrush has high or low it actually stores the type of the brush so if you look at that brush you can actually see it's a Sony care white and that's yeah I remember buying that particular one for no particular reason other than it was cheaper than on Amazon it's got a manufacturer's code it's got a unique ID that's quite a lot of information oh look at that it's even got a web link unbelievable so Philips claim that they actually monitor pressure data I'm not sure how true that is let's do a test.

So what I'll do now is I'm going to take the brush off my actual toothbrush body, the one I've been using for a long time.

So just to give you a comparison, the new versus old, you can see the blue stripe has pretty much all gone the old brush, this one.

I'm going to clear that data and now I'm going to read the old brush head and you can actually see this has been used almost 84 % of its exact life. Five hours, one minute.

That's quite a lot of brushing and it does a maximum of six hours look.

I'll be using it on high, that's the mode of the toothbrush, all the other stuff looks pretty similar to the new one. Let's do a test.

So let's see what numbers change when we actually do a brush. I'm going to connect it back to my handle.

So what I'll do is I've got the old brush head installed back on the handle and now I'm going to do a high power run. I won't make you sit through that.

So there you go it's finished. Spread a bit of water on the table. Let me take the brush head off.

So if you remember if we look at our screen it'd been used for five hours one minute and eight seconds or 83 .65 % of its lifetime.

Putting the used brush that's just had that two minute run on the reader.

So now you can see it's read has gone up five hours three minutes eight seconds interesting.

So what I'll do now is I'll do another two minute run but I'll do a low power this time I'll see what happens and to get low you press the the on button twice so there you are it's running on low now okay it's finished it's a two -minute low power run okay so look it's gone up exactly two minutes and now it's recognized last used slow low power interesting so I'm a little intrigued by this because both the low and high power both just registered a two -minute run and so how is actually the the system logging what pressure you use I didn't really see anything change so I think what I'm going to go do now is I'm going to actually go and brush my teeth with this brush so we'll do a read of it so you can see last used at low power levels and it's got five hours five minutes and eight seconds of usage I'm going to go and really brush my teeth with it so I'm back let's see so five hours five minutes eight seconds usage so I'm going to clear that and put the brush back on the reader so I've just brushed for two minutes on high. Let's have a look now.

Okay, that has gone up quite considerably.

So basically what seems to be happening, he's gone back to high you see, it seems that the brush it's obviously detecting how hard I push because I know that because when I'm brushing my teeth I can it vibrates has a slightly different vibration if you press too hard so there definitely is some kind of pressure sensor there and it seems looked that that's increased the usage time more than two minutes and I know I was pushing quite hard because I could feel that that alarm basically going off so let's go and do some analysis on this data.

So the brush started with five hours one minute of run time and run one and two with dummy runs with no pressure and they both clocked up two minutes of usage time for two minutes of actual run time run three and four clocked at more than two minutes each despite the brush itself actually operating for just two minutes so it seems the toothbrush actually applies a multiplier depending on how much force or pressure you press on your teeth quite interesting way of doing it so the next obvious question is can we actually write to this brush head and if you look down here you can actually see some mention of a password here.

So actually writing to the brush is protected.

You can't easily do it with this NFC reader writer, but there's been some really hard work done by a few other people.

And that includes Marcus Berth.

So he's done some great work on how to actually decode and dump all the information out of the toothbrush head.

look at all those different modes you identified. And also the work of Cyril Kunzey.

So he again actually did some reverse engineering on the brush head and their work together actually made a github repository that you can actually use to be able to write to these devices.

So that's exactly what I've done so that's the data from my last read.

If I go into program mode, watch this.

I take my toothbrush, hold it over the reader and reset it to 50%.

So there it's read it, purples indicates the right and now it's going to read again.

Okay so it's confirmed it's reset it to 50%.

Let's go and do another read.

Clear that old data, put the toothbrush back, read the brush now and look at that.

Recorded runtime, 10 ,800 guest seconds, units, three hours, 50 % remaining.

Not sure what's the point in doing that though because it doesn't make the brush any younger looking but there you go you can actually write to them but that gave me an idea what else can I do with this brush.

Well I certainly don't like making a lot of plastic waste and when I get a horrible toothbrush like this I'd like to find some other use for it so watch this you can actually use it to unlock your computer let's try that again how cool is that like us again get the new brush let's see what happens now no look at all nope only this horrible old brush can unlock that computer pretty cool hey so the question is can we actually get the thing out I think so let's try to get the metal collar out first that came out quite easy look at that so there you go it comes out so easy can we investigate further so excuse the shaking here I am on my phone because my actual camera I used to film the videos is not so good at close -ups.

So there's the antenna, let's try and get it out.

Oh yeah, it lifts out nicely.

So you can see the little antenna ring going all the way around and the little microchip embedded there.

I won't break it down any further.

But this will still unlock my PC, so I better not lose it.

Quite a So just to answer the question, do two brushes need microtrips?

Helm the hoe! They certainly don't, but it is a pretty cool technology.

I like how it records both the time and the pressure that you're putting on to give you an indication of when the brush is used up.

But anyway, I wonder if there's any interesting ideas that you can come up with for the used brushes.

So if you found this video useful please like and subscribe and if you've got any comments put them down below. I'll see you in the next one.