How to build a super-slim smart mirror | Hacker News Reader

How to build a super-slim smart mirror

raspberrypi.com

177 pointstambourine_man51 comments

How are there exactly zero photos showing how slim this thing is/isn't!?!

EDIT: In other news, the settings menu of Pi Imager is brilliant. It automagically fills in your RSA public key, your WiFi details, and other time-saving details. I can't believe how hard we had to fight the RPi devs to make the feature usable and stop hiding it behind a weird keypress combo (to the point we released a fork). They were obsessed the extra options in there would confuse newcomers too much. Those devs were weirdly condescending and really hard to work with, I won't bother again.

They link to the display to use on Amazon. It's very thin at 1 cm.

But then they use spacers to make it thicker in order to fit the RPi inside.

It's sad that the Raspberry Pi, which was originally conceived as a simple and accessible computer for people to learn new skills, has become so intertwined with the user-unfriendliness of Linux. (The comparison with the simplicity of the original BBC Micro is comical.)

You give one example of how the devs (who, of course, fully 'get' Linux and are fully bought in to the experience) have seemingly little insight into how this impacts less able users. (Somehow they think that creating ssh and wpa_supplicant.conf files in the boot folder are less confusing then an extra option in the installer!?)

Other examples (from my very recent experience) include simply trying to install fairly mainstream libraries on a Pi: it took (literally) several days, multiple retries, multiple failed approaches from blogs or stackoverflow, before I could get a working install of python-opencv. (And my final 'success' was just sheer luck, plus trial-and-error, I think).

And there are other examples; every time I start a new project thinking the Pi is the perfect starting-point, the ultimate time taken is 5-10x what it probably should have been.

If the user experience is this bad for someone with otherwise strong IT ability, how on earth do they expect anyone with less expertise to succeed?

I don't think Linux is user-unfriendly if you want to learn how computers work. Also, if you want computers for the use cases that a RaspberryPi is intended for, then what other OS choice is there? Heck, just having an OS is an overkill of luxury for most of those projects to begin with.

It's unfortunate that you had such a bad experience, but it sounds like you might have had unhelpful expectations.

Probable that easy reinstall and mass deploy are the goal as opposed to "less confusing".

Somewhat hilariously they only relented on their refusal to make it easy to set WiFi and ssh up in the imager after somebody forked it and added those features.

Anyway I totally agree with you. I wish the Pi had decent support for writing bare metal code in the same way you would write microcontroller projects. 90% of the time all you want it to do is connect to wifi, and run one single program.

Running full Linux for that makes it actively worse than a unikernel / FreeRTOS style solution. But I expect the difficulty of making WiFi, USB, cameras, etc. work without Linux is too great.

I upvoted your comment because it challenges the assumption that Linux is The Only Possible Platform.

Reflecting on this assumption, I realize that Linux is the most widely supported platform to which the Raspberry Pi Foundation can retain some measure of control.

Some. But the Foundation can't fund the development of all the software, and their tweaked Linux is good enough for them, so that's what we've got.

> How are there exactly zero photos showing how slim this thing is/isn't!?!

There is a render[1] with the 2mm and 3mm acrylic they call for. Judging off of that, this thing is probably 11-12mm thick

[1]https://www.raspberrypi.com/app/uploads/2023/01/Screenshot-2...

I made one of these (not this fancy, just a recycled Android tablet mounted behind one-way mirror glass, running a home-made app) and highly recommend it. I was 100% prepared for it to be a novelty that we got bored of in a few months, but eight years later it's still awesome! You can see my mirror and app code at https://github.com/ineptech/mirror but the version in the play store is outdated (weather and stock ticker apps are broken due to the free APIs going away) and I've lost the Play store signing key needed to update it.

edit: biggest "lesson learned" I'd add here is, I experimented with both touch and voice support but didn't like either. I already have laptops and tablets aplenty to interact with, I prefer to use this mirror like a clock - glance at it when I want to information, and otherwise ignore it.

> I experimented with both touch and voice support but didn't like either. . I already have laptops and tablets aplenty to interact with, I prefer to use this mirror like a clock - glance at it when I want to information, and otherwise ignore it.

Clearly the answer is machine vision/camera/gesture input :)

Maybe expression recognition - smile for weather, frown for stock ticker... :)

I went to do this sort of thing the other day.

First thing I did was try and find a Pi Zero 2 W. Discovered most models of Raspberry Pi are completely unavailable. And so, another side project was canned.

Wow, you're not kidding! I checked ebay and saw one bid to $50 and another buy-it-now for $93. For a Pi Zero!

That has been the situation ever since the worldwide chip shortage hit. Raspberry Pi (the company) decided to prioritize companies that use Raspberry Pi's in their products over consumers. So it became almost impossible to get a Raspberry Pi, unless you were willing to pay a huge markup to a scalper.

The situation should improve this year though.

> As a result, we can say with confidence that, after a lean first quarter, we expect supply to recover to pre-pandemic levels in the second quarter of 2023, and to be unlimited in the second half of the year.

https://www.raspberrypi.com/news/supply-chain-update-its-goo...

It's not entirely their fault. The Raspberry Pi foundation has very close ties to Broadcom, who make all of their CPU SoC's. The original Pi was made with super cheap chips Broadcom was struggling to sell to anyone else. Either a batch of SoC's that didn't sell as well as expected, and later fabrication capacity reserved at a foundry that it later turned out wasn't needed.

The Pi foundation basically sucks up overproduction of chips from Broadcom, in return for low prices. But when there is a chip shortage and no overproduction, they don't get any.

Our trailer has a 'cloud gateway' that allows you to see/control it from the internet. The box that does that is a raspberry pi with a dedicated hat to power it, in a custom box. They want $450 for a new one when the Pi's SD card poops out.

It’s been the situation for years, I drove 30 miles for a zero like 6 months after they were released. I bought an A because the B was sold out in 2014.

As it's not mentioned yet: https://rpilocator.com/ might help getting a Pi at its intended price.

Yep. I got all excited to set up a PiHole at one point during the pandemic and then realized how impossible it was to actually buy a raspberryPi and gave up. Hopefully one day

Linus Tech Tips recently listed like 10 raspi alternatives.

Yeah, but take all of those with huge grains of salt. Some of them will only run the vendor’s custom kernel, others have library/driver incompatibility issues, the non-Pi SBC ecosystem is a bit of a crapshoot. And I say that as someone whose primary non-Pi experience is with the fairly well-supported Jetson Nano. You quickly realize why Raspberry Pi is so beloved.

Don't bother with that video, he completely ignores the software aspects of the boards.

If you've got an old dead/useless iPad lying around then taking the screen out and reusing it can be good fun. https://youtu.be/ENKhizrCuPU

The guide is a bit lacking - I made such a foil based smart mirror and the mirror you get from just a foil is not good. I would more call it a reflective grey surface than a true mirror.

So I would suggest getting a proper partially silvered glass sheet and getting the money for that by not using a currently overpriced and hard to get raspberry pi.

Where can i buy that is premade so all i have to do is hook my PC / Pi up to it.

I'm betting IKEA will have such a product in the next 1 or 2 years.

There is still no touch input. If the display has PCAP that can't reach through the mirror then this type of module would add touch on top of the mirror.

https://neonode.com/technologies/zforce/touch-sensor-modules

Fingerprints on the mirror won't look that great though.

Oleophobic coating mirror but that will add to the cost

My wife had a monitor die early (16 months?) and I'd LOVE to turn it into a screen. The problem is that I'm betting the panel is fine, and the power is fine, but finding a driver board is near impossible, and I don't know enough about driving a screen to roll my own. (It's a 24" 2k screen, which would be awesome, and I kinda don't want to recycle it if I can conceivably reuse it.)

You're probably best off looking for the same model monitor with a broken panel but working driver board.

there is a roaring trade on ebay/aliexpress configuring generic HDMI/VGA->LCD panel driver boards. once you strip down the monitor, get the model number of the actual panel and google/ebay/aliexpress search for <panel model> + hdmi driver and you will probably find one in the $20-$40 range. a typical example is take a 1st/2nd gen iPad which has been locked out (and therefore useless to anyone trying to unlock it without the original iCloud account) usually sell for about $/£10 on ebay, strip out the panel and pair with a $20 HDMI->LCD interface for a standalone 9.7" IPS monitor (albeit at 1024x768 res but the clarity is amazing)

This is all great but don't underestimate these mirror displays: A friend built a similar one and disabled it when he saw the energy consumption. And this was a few years back. Still waiting to pull the trigger on an appropriate e-paper display.

At least I'd suggest to measure the setup before you commit to the whole crafts project.

Use a PIR motion sensor to only turn on the screen when someone is around. Mine has been running for years with a 27" LCD inside, the average power use is negligible when it's in <1W standby most of the time.

I was thinking about a similar project once and the electricity cost was about $1 / month. Am I way off on my calculations?

At the current electricity prices we're paying here (~$0.35/kWh), this would be around 4 W of continuous consumption. That's not a lot, you can basically power you Pi with it, but not the screen... count at least 10x more costs to operate the screen 24h a day. But as mentioned by someone, if you use a sensor to only turn on the screen when there's someone in front of it (and if you actually turn OFF your screen when there's nobody, and not just display a black screen), then you can almost remove the display power from the equation, unless you spend your day in front of the mirror.

On the Raspberry Pi, you can pretty easily switch off the HDMI output via shell commands, which sends most displays into low-power standby. It takes a couple seconds to switch back on and wake the screen when activity is detected, but the tradeoff is easily worth it.

How much energy to run a microphone, waiting for "Mirror, mirror, on the wall..."

I don't think an e-paper display would work in this case, though? The nature of two way mirrors requires that the screen actually emits light (instead of just reflecting it) for it to come through.

Maybe an OLED panel would do the trick though, since most of the screen will be turned off. Probably much more expensive to get one of those, though.

For a mirror no, for displaying the same information yes.

Just a few days ago, I thought to myself... "We are in 2023 but still no smart mirrors" like in "The 6th Day" Arnold Schwarzenegger film. ^_^ Very cool project.

I have some friends that have a bedroom wall TV that is a mirror, when it's off.

I suspect that it cost quite a bit. They have a nice crib.

All my TVs are mirrors when they're off. Just really bad mirrors.

It's not that expensive to buy a mirror that covers your TV. I'm not suggesting I have any clue what your friends setup is and if they used a dielectric mirror it was probably pretty spendy compared to the price of TVs today: https://www.twowaymirrors.com/tvmirror/

The text says not to go lower than 300 nits for the display, but the linked display is 250 nits?

Something like this looks so cool, but I worry about the security of it, and the energy consumption.

About which security risks do you worry?

its a computer that connects to the internet. What isn't their to worry about?

I suppose none of your other computers connect to the internet, otherwise you'd be in a constant state of worry.

It's just a screen behind a mirror. No cameras.

Doh! I was expecting something about mirroring databases.

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