The Game: Screen Test

In the last post we successfully cut a hole in the TV screen to make space for the siren, so the next step is to secure it in place and make a translucent filter for the screen.

First though fitting that siren – as luck would have it I had a small metal 90 degree bracket that was exactly the right size to fit between the siren’s mounting bracket and the side of the TV case. The holes needed to be drilled out to hold larger bolts, but with a bit of fiddling it was rock solid.

Next was the screen filter. For this I printed a “TV Snow” image onto an A4 Transparency sheet (the kind you’d use in old-school overhead projectors) and then trimmed it around the existing screen with a craft knife. With everything test-fitted together I placed the assembly in front of the Pi prototype rig so that the Unicorn pHAT would shine through the screen. It looked just the way I had hoped, lots of indirect light and a bit of a glow to the screen, which will hopefully look even better when the inside of the TV is painted white.

Next time we’ll be moving on to the remote and the rabbit ears.

Project updates so far:

1: LCD Shutters
2: LCD Glasses
3: TV Teardown
4: Screen Cuts

Once complete there will be a full YouTube video so you can follow along and make your own!

The Game: Screen Cuts

With the TV dismantled  the next stage is to start fitting the other parts together, firstly the siren. The siren needs to poke through the TV screen, so the first order of business was to cut a hole for it.

Initially I thought of using a hole saw, but the screen is so bendy and fragile I had a feeling that would end in disaster. I decided to use the Dremel to nibble through the plastic, later using a sanding attachment to clean up the hole.

It all went really well, all limbs and digits are still intact and the hole is both the right size and neatly cut. It fits perfectly over the siren, and test-fitted together with the TV it’s really starting to take shape.

Next on the list is fitting the siren permanently in place, and sorting out some kind of translucent image for the screen, one that will display the different lights controlled by the Raspberry Pi but not let you see all the way inside the TV

Project updates so far:

1: LCD Shutters
2: LCD Glasses
3: TV Teardown

Once complete there will be a full YouTube video so you can follow along and make your own!




The Game: TV Teardown

The next stage in the “Game” project is to prepare the portable TV for its new function. Dismantling is always one of the most fun parts of a new project as you never know what to expect when cracking something open for the first time.

This teardown went really well, four screws to remove and a few snips with the wire cutters left just the outer shell, which is the bit we need. There’s also a convenient earphone socket left over that we’ll eventually use to plug in the LCD Glasses.

Now that the TV is in bits the next thing is to very carefully cut a hole in the plastic screen to hold one of the most critical parts of the game – the siren. Once that’s done we can start figuring out where all of the other parts will go, and how it will actually work.

Project updates so far:

1: LCD Shutters
2: LCD Glasses
3: TV Teardown

The Game: LCD Glasses

The Game is coming together, using the fancy new black hot glue I’ve now added the LCD shutters to a pair of old shades for testing. 

They’re now fully wired up to a 3.5mm stereo jack plug and cable, which clips into a socket connected to the Pi’s GPIO. The gif above shows the shades turning opaque and clear based on a Python script.

The shutters are working well, the GPIO control pulls them from clear to dark instantly, so far I’ve tested intervals as short as 0.3 seconds with no problems.

They really mess with your vision when wearing them (which is the entire point!) but the shades make the whole experience a bit darker than I’d hoped – mind you I’ve only tested them in the workshop so far, which is a bit dim.

What’s The Game all about? Keep your eyes on future posts! The next stage is dismantling a 1980s portable TV.

The Game: LCD Shutters

I picked up these LCD shutters a while back from Pimoroni, essentially because they were a new product and I was sure I could use them in a future project.

As they say on the Pimoroni product description:

Essentially single pixel LCD displays, these panels polarise and go black (completely opaque) when you pass 3V through them, and then de-polarise (become transparent) when pulled low or shorted. Easy!

You can treat the LCD shutter like a low value capacitor. Once energised, they will hold their polarised/opaque state, but slowly leak charge over time and become de-polarised/transparent again

The shutters were really well packaged (as you’d hope for something so fragile) and had a clear plastic protector on both sides, which is handy as you’ll handle them a lot.

As you can see in the GIF they go completely opaque when you attach 3v, then slowly become clear again (unless you pull down or short the connections). They don’t seem too fussy about polarity.

This week I finally nailed the concept for using them in a new Raspberry Pi project, which I’m calling “The Game” for now – a long way to go but there’ll be regular updates here and a YouTube video of the whole build when it’s finished.

Begging for Conversion

When rummaging around for old tech at sales some unloved pieces just leap out at you and beg to be upgraded, like this old intercom phone we found at Beccles antique market at the weekend.

It’s a fairly standard old phone, but with a grille where you’d expect the rotary dial to be! The stallholder thought it was originally from an RAF base and it does have that vaguely military / industrial look to it.

It cost around £7, hard to say exactly as I bundled it with some vintage Babycham merch for the Progress Bar. What really appealed to me was how easily this phone could be converted using the Google AIY Voice Kit – it has a grille for the speaker, a built-in button and even a translucent red lens for the indicator LED. Couple of drill holes for the microphones and that’d be it.

With minimal work this could be turned into a unique and practical voice assistant. Most of the work would be on the cosmetics, it’s obviously been exposed while someone’s been decorating as it’s absolutely covered in tiny flecks of white paint.

It’ll clean up though, and with a lick of paint for that grille it will make an attractive bedside voice assistant – especially useful for those weekend “bring me a cup of coffee” broadcasts to the kids.