Your last image shows that your sewing machine plug has no earth ground. I’m not well versed in sewing machines enough to know if this is typical for sewing machines, but typically any appliance with no earth ground will insulate the user from either conductor.

You cannot count on the neutral wire to safely ground anything that the user touches.

Your readings indicate that there’s a small amount of voltage coupling onto the housing. Voltage alone doesn’t indicate much if there’s no current behind it, so it could be safe, but as another user indicated, you probably want external metal bits to be earth grounded. That’s the whole point of earth ground.

Sorry, by precise I mean “specific timing requirements with respect to each other” not “parts per million”

I think ever my clock has a few dozen nanoseconds of slop, but the whole clock pattern is difficult to create without a bunch of discrete logic.

It’s far too fast to do it in software. Thus the FPGA.

But yes, it needs a very specific set of six clock signals. Not something easy to achieve with discrete logic if that’s what you’re suggesting. data sheet

Yeah the reference design uses a display driver from Epson that’s eol.

Haven’t looked at integrated display controllers. That’s certainly interesting. It’s a pretty unconventional display. Sharp memory LCD with 64 colors data sheet. I’ll have to see how configurable the integrated controllers are.

Looked at the max10. Still too pricey. Hoping for something in the <$1 range.

I think that’s a Qualcomm proprietary thing that isn’t supported by standard USB downward facing ports.

Good idea, but the ribbon connects to the other side of the connector.

Yeah, I figure I’ll provide the option of soldering, but I’d just like there to be some other method as well.

Yeah, the GVDCVG is ground, voltage, data, and clock. My board is going to sit between this ribbon cable and the part that normally connects there.

You do make a good point though. I was hoping for an elegant solution where this ribbon cable was the only connected component, but there’s a large exposed voltage testpoint exposed nearby. It’s 1.5mm wide and 3mm from the board edge. I bet I can find a miniature allegator clip or some other way to connect to that.

The iron would probably triple the cost of the kit. The ewaste being diverted here is a $17 vape pen.

Everyone needs to start somewhere. The goal of this project is for an everyman to repurpose some e-waste. Hoping to maybe inspire a few people to learn more.

The circuit in question draws a decent amount of current (probably like 100mA or so), so I thought it better to short the signal line than try to power it directly.

Alibaba is talking directly to the manufacturer. At least in my experience. Haven’t heard of trade wheel.

I might. I already emailed them for another project asking what model screen they were using, and they refused to share that info, so I don’t think they’re too open to hardware hobbyists.

The other project was adding a light. There is a vendor that offers a front-light for that model, but it’s like $60 and the result is too thick to fit in the stock Playdate.

Yeah, I hit up a few on Alibaba. Even one who can apply the black border on the glass. No responses so far and it’s been a few weeks.

Your drawing is a little confusing. Here’s what you need:

There’s nothing special about a setup with a light in the button. It’s literally just an incandescent bulb across the button. If you connect your circuit across the button terminals, it’ll work fine.

The 4 diodes in a loop is a “full bridge rectifier” that gives you DC from AC. The 5V regulator could be something like an LM7805.

The “large capacitor” is to keep power applied while the button is pressed, though you might be better off in that case with some small onboard battery. You just have to make sure that your battery charging circuit doesn’t draw too much power.

So a doorbell transformer steps 120VAC down to a lower AC voltage. That’s what you’re measuring (surprised you can’t tell if it’s AC. Your multimeter should have an AC/DC setting).

The circuit puts the transformer, the button, and the bell (classically an electronagnet that accelerates the hammer) in series. When you close the switch (push the button) the hammer strikes the bell.

An electromagnet is just a coil of wire, and it is possible to pass a small amount of current through it without activating the hammer. If you’ve ever seen a doorbell with a light up button, the light bulb is placed in parallel with the button. That way it’s always on drawing a small amount of current. It also explains why the light switches off when you press the button. You’re shorting across the bulb, so it’s voltage is zero.

If you want to use this power for an electronics project, you’ll need to find a way to draw just a small amount of power from the transformer. It has to be very small or you’ll activate the hammer.

Drop a full bridge rectifier in parallel with the button, then a bunch of caps to give you a steady-ish voltage and then some kind of voltage regulator to make it useable.

Just remember that you can’t draw too much power, and you’ll lose that power whenever the button is pressed.

and nobody knows how to code anything and read datasheets anymore.

You seem a bit bitter which I can relate to. As someone who cut his teeth writing assembly for an 8051, I remember feeling a bit cheesed by people using arduinos to do what could be done with a 555.

My career has gotten comfy, but I can feel my skills stagnating with all this new stuff coming out. I of course would never ship a product with a Raspberry Pi embedded in it, but I’d like to have a feel for how to solve problems using newer more advanced hardware. With that in mind, do you have any recommendations?

The closest planet to Earth is Mercury.

On average that is. Mercury is actually the closest planet to every other planet in average. Because when it’s on the other side of the Sun, it’s still pretty close.

I watched Funny Games in theaters in high school and it pissed me off so much. I literally shouted “fuck you” at a screen in a public theater. It wasn’t until much later that I realized that was the point.

I’ve been meaning to watch it again.

I did!

And now I’m learning it’s based off a short story. Gonna have to pick that up.