Topic: Making

Game Boy Speaker Repair

2018-07-29 13:33 - Making

The Game Boy Color, open, with the new speaker installed.

I recently picked up a Game Boy Color for cheap, due to an issue with the sound. This is a common issue, the speakers wear out or break over time. Replacements are easy to come by, and cheap. Here's mine, with the new speaker in. Turns out the cheap and easy to get replacements aren't quite perfect. The original speaker (with the "Z" on the back, outside the console) comes in a plastic case, with some nubs on the outside to hold it in place. The new one fits in that space, but it's a bit smaller. A few dabs of hot glue should keep it from rattling around. And now my Game Boy Color has sound again!

RFID Reader v2 Starts

2018-06-07 23:14 - Making

The first working prototype of the next version of my RFID reader project.

I've used Arduinos for some time now, for electronics projects. They're very easy to get started with, but a little bit limited. As I called out in the VFD clock project I did a few years ago, STM32 is a nice next step up. Pictured is a Maple Mini clone I still had from that project, easily available for around $5. Even better is the (as it's colloquially known) "Blue Pill board with almost the same functionality at around $2, and it's close cousin the "Black Pill". More speed and RAM and Flash, more peripherals. More exciting!

I designed a multi-headed RFID reader project, on top of an Arduino core. After some delays it's finally seen real usage, and revealed several opportunities for improvement. Mostly around the hardware, but if I'm going to redesign, I want to take the opportunity to revisit the software as well.

On my clock project, I found the SDK very detail-heavy and hard to work with. ST Microelectronics, which makes the STM32 chips, also makes a package called STM32CubeMX, a code generator that makes the SDK easier to consume. But it wants to output projects that specifically work with a small handful of professional (read: $$$) IDE packages. I recently discovered that Atollic TrueSTUDIO, which is in that list, is available for free download! I've spent a fair deal of free time, in small chunks, recently getting these all set up and working, and especially understood.

The plan is to take advantage of FreeRTOS, which the Cube tool can include with just a click, to handle scheduling and some other things to make this next version both faster and more stable. For now at least, I've got a proof of concept, working end-to-end, able to read cards and developed with a capable IDE with breakpoints and value inspection built right in.

Custom Game Case, from Unused Koozie

2018-05-29 17:12 - Making

The pair of source Koozies, with the Game Boy Micro on top. Top sewn up, bottom cut open, sides sewn. Flipped right side out. Tucked in. Flap closed.

Several months ago I got a pair of Koozies, which have sat unused since then. More recently I've pulled out my Game Boy Micro, which has no protective case, unlike most of my portable devices. I realized that the Koozie was the right sort of material, soft and padded, and almost exactly the right size. So I cut one side of the bottom off, sewed closed the top, and sewed the sides in closer, to be the right size. After flipping it right side out and confirming a good fit, I trimmed what was the bottom of the Koozie down, to be a flap which I can tuck in to cover the open side. It worked out quite nicely!

The wi-so-serial works!

2018-03-24 21:33 - Making

The first working wi-so-serial, installed.

For months, stalled by a partially broken computer, I've been working on this project. I have a server at home (and another for remote backups, at a relative's house). And I've got full disk encryption which needs a password to unlock, at boot. Which means if it ever reboots I have to physically be there to get it going again. I'd like to be able to administer my servers remotely.

I've looked into commercial IP KVM devices, but they cost hundreds of dollars. Since I'm working with Linux here, in theory all I need is a serial terminal. So I've designed a serial-to-WiFi bridge. The picture above is the first one that I've ever had working, installed. The ribbon cable hooks up to the internal serial port header, the green terminal plugs into an unused USB port header for power. Then there's snaking trails of several other pairs of wires: one each hooking to the case and to the motherboard for the power LED, the power button, and the reset button.

Most newer motherboards power their USB ports all the time, even while the computer is off, this one included. So I can remotely power up or down, restart, and then control the computer. In theory. I've just gotten far enough to test all this, and discover performance issues. I've got all the computer-side setup to manage, yet. But after working on this since August, it's great to have it finally proven to really be workable.

Hokkaido Milk Bread

2018-02-20 14:31 - Making

I recentely learned about the tangzhong bread making method. I pickeda recipe and decided to try it.

The dough is formed. Dough has risen, is divided and rolled and set in (the wrong) pan. Baked!

So I made the dough first of course. Then, I didn't know where my Mom kept her bread loaf pans so I used a Bundt pan instead. And I don't know where the pastry brush is, so I didn't do the egg wash. But it still came out quite nice. Very dense, and certainly tasty. Worth trying again with a few more details "right".

Custom Garbage Bag Holder

2017-12-25 20:24 - Making

The bag holder, "in place" except lifted up a bit for demo purposes.

Just in time* for Xmas, I put together this custom garbage bag holder for my Mom. Following availability at local grocery stores she's switched to plastic bags, and been awkwardly using them on this built in garbage bin, where they're too small to fit properly. Here's a mostly plywood contraption to fit over the existing bin, but with pegs to hold the bags' handles plus some cove molding to help keep the bag open and in place. It's about the same depth but narrower than the bin beneath it to be the right size for standard plastic shopping bags. A cutout in the lower layer of plywood fits around the lip of the bin, while the top layer holds all the bits mentioned above. It's all made from found materials already around the house, which is the perfect kind of gift for my Mom. No new/extra stuff!

* I definitely had an idea to do this over the Thanksgiving visit. And earlier in this visit. And forgot, despite a coded (to not give away the surprise) note to myself. Then I thought of it again, and realized what the note meant, and built this up over (mostly) a long afternoon on Xmas Eve.


KQ Button Tester; nee Turbo Button

2017-11-16 22:19 - Making

My KQ Turbo Button device, on a messy desk.

I've never posted here about this device I made. I made it earlier this year, mostly as a joke. On the right, now mostly hidden by the fan, is a solenoid. It sits poised above a yellow arcade button, also mostly hidden by the fan. On the front of this view is the electronics and the controls are on the top, all glued to a huge 12 volt lead acid battery.

The original point was to be able to press that button with inhuman speed and accuracy. I managed to leverage that to contribute to some of my videos about Killer Queen. More recently I've been interested in figuring out how to pick good arcade hardware. The moving parts wear out and need replacing. Which ones to buy as replacements?

So I updated the device, not only can it push the button — normally the one in the real arcade, now (in the extra little bit of wood it's sitting on) a dedicated one — it can read its value. So it can be used to derive fine details about the performance of the button, when pressed. I want to do quite a bit with this. Here's one example:

ED 0
D 12272
U 12280
D 12284
U 12540
D 12832
U 12836
D 12844
EU 0
U 8364

That starts ED 0 for "event down zero". Then a bunch of lines D and U indicate the timing of "down" and "up" events observed, in microseconds since we started the "down" event. All real mechanical switches "bounce" a bit when activated (and deactivated, usually). In this case, the button first went down about 12 milliseconds after we started (it takes some time for the solenoid coil to charge up, then to physically move) and the switch contacts bounced apart and back together three times after that, taking just over half a millisecond to settle down into its final resting state. And in this case when it came back up, there were no bounces. In my limited experience so far, this looks like good performance for such switches.

This is just one bit of data but we can compare quality in the "bounciness" category pretty easily: how many bounces, and how long before the last one is done? I intend to follow this with a post containing a detailed summary of this, for several switches. I need to make a final call on exactly what I want to measure, and make sure my tool will do that if at all possible, so it will take a little time.

PCB Prototyping Service Review: JLCPCB

2017-10-01 10:46 - Making

Scan of a board produced by JLCPCB.

Disclaimer: the PCBs pictured and discussed in this article were provided to me at no cost, in return for writing this review. I've received no other compensation and this is my own personal un-altered opinion.

Recently I was contacted about a new PCB prototyping service called JLCPCB and asked to do a review. I've done a few of these over time, and this is much the same. Pictured at left is four copies, two front and two back, of the board that I had made for this review.

It's a simple board so I can't comment on high density pads, but all of the traces, holes, and solder mask appear to be well aligned. The silkscreen is solid and legible everywhere. Overall, I would say these are perfectly fine boards.

I got ten copies, and they were all generally fine. Look (very) closely at the far bottom right of the image, though. You'll have to go full resolution to see it, but there's some scuffing around the pads near the bottom middle and bottom right. Cosmetic only, it seems, and the other nine boards had no issues or only even more minor scuffs/scrapes.

Cost

JLCPCB's claim to fame appears to be their $2 minimum cost. This applies only to the first board in any given order, and shipping from China applies to any order. So really you can get a few copies of one board made for $2, but you can only get it delivered for more like $12. Add a second board to the same order (e.g. to share the shipping overhead) and it will be $5.

Customer Numbers

Just like EasyEDA, this is some sort of batching service, which adds customer numbers in the silkscreen. They do say this ahead of time, but as I've called out in earlier reviews, I really don't like it. Especially here. I explicitly put in the in the "remark" box that I'd prefer this number to be located under U2 or U1. It would fit in either place. But instead, it was put out near the edge in the most visible place.

Final Call

These are fine boards, there's (almost) nothing wrong with them. But if I'm going to pay a couple bucks for the boards, plus $10 to $15 for shipping, I'd rather go with Elecrow's "special" service, ten copies up to 10x10cm for $5 — with no extra customer number printed.

Quarto Game Board

2017-08-11 12:57 - Making

I recently discovered (via the awesomely named YouTube channel I Like To Make Stuff) of a board game called Quarto. It's got simple rules and it's pretty easy to make a set yourself. I'm visiting my Mom in New Jersey, and that means access to some tools I couldn't keep in the city.

Rounding the material for half the pieces. The pieces are all rough cut out.
The board is a grid routed into some already-finished wood. Complete!

I picked some already-one-inch-square scrap available, it seems to be PVC. I rounded off the corners on the router table, then cut out eight short pieces and eight tall pieces, half of each from the rounded over section and half from some raw square section. Then half of the pieces got holes drilled in the top, and half got spray painted black.

The board is another scrap piece, of wood that was already finished. A grid of shallow lines, again with the router table, formed the play spaces. I chamfered the edges and with the paint dry, it was done!

This was a quick and dirty project. The grid lines were not routed the best, and the spray paint leaves a lot to be desired. But they're definitely good enough to play with. So I'll give that a try, and then decide if it's worth trying again, with perhaps better materials and more care.