Busy hands | Disquiet mind

Divoom Pixoo Slingbag is nice looking bag, with a 16x16 RGB LED screen in it. I was curious and wanted to look inside. (I must caution you if you buy one for yourself; there are always discounts, don't pay full price. And their after-sales marketing is often overwhelming.)

The bag is constructed well, of decent quality materials. The LED grid works very well. The app for it, on the other hand, is absolute hell. Other people have made alternative clients for them, like the DivoomClient for ESP32, Divoom Timebox Evo, but the only one I personally tried out was the Windows Diwoom client. Which worked pretty well, but made me realise the bluetooth communication isn't protected at all. If there isn't a client currently connected to the bag, there's nothing stopping anyone else from connecting and changing the displayed image. So clearly the hardware had to come out.

( Details )

Outside view of the bag, new display in place, running Rainbow example
Photo by chebe

This bag is quite eye-catching, and people have asked me questions about it whenever I've brought it out. I look forward to customising the animations, eventually. There are repos that will decode the actual animations from the app, but there doesn't seem to be a ready library for implementing them in MicroPython (I saw a promising one for CircuitPython, which alas is not MircroPython), but I'll keep investigating. Also, the original display is still functional, so that might find a use somewhere that isn't public.

I'm not of an Alpine culture, I didn't know what a Krampus was, but I mean look at how cool this Merry Krampus surface-mount soldering kit looks! I wanted it. (It's also available on Tindie, but the Challenge version seems permanently sold out.) I found and ordered it last year, but it arrived in January, so I put it in a drawer until recently. I got the Challenge version, because a little challenge in your life can be good for you.

Slight hitch being, I didn't have any surface-mount soldering tools. So I had at the kit with my regular soldering tools. The instructions are thorough, and it even comes with a programmer that you need to assemble. But when I got to the point where I could program the board it just wasn't working. The LEDs at the eyes would blink, but then the Arduino IDE would complain that it couldn't communicate with the board. I emailed the creators, and was surprised when they replied, with even more detailed info to help me through the process! Seriously, they are lovely people.

I examined the circuit diagrams, figured out which pins on the board were which on the diagrams. I multi-metred my way through all the connections. It all seemed good. The next step was removing the transistors. I did not fancy that with my standard soldering iron, so I ordered a SMD Repair station (a.k.a. a very hot air gun). Before trying to remove the components I hit every single solder joint with the hot air. I couldn't see anything happening, but the plastic parts of the switches are very toasted, so stuff was happening. Then I tried programming the board, and it worked first time! My guess is I had made connections (multi-metre said so) but that they weren't good enough. Reflowing the solder must have helped strengthen the connections. After that you can add decorations and ways to attach the board to things/you. (There is also the challenge of changing the programming, but I might save that for next year.)

( Pictures )

Finished, and programmed board, all lit up
Photo by chebe

Of course, if you don't enjoy this kind of challenge you could buy the presoldered version, or even the solderless version, which is new this year. But as frustrating as it was doing this kit without the proper tools, it really does feel like an achievement to have it working!

Three years ago I posted about a little Tree of Lights that consisted of conductive paint and auto-changing RGB LEDs. Over the years I had to mend some of the connections with wire glue. But, again, this year, I found that most of the connections, all but one actually, had broken. The LED legs had physically broken the traces by pulling away from the tree-form.

So I gave in and soldered silicon wire between all the connections. As wire has much lower resistance I needed to add resistors as well. I also added proper wire connectors for ease of adding power, and added so much hot glue to try and hide the wires in the pre-existing paint traces. The main benefit of the wires is that now the whole thing runs happily off 3Vs, whereas before I was struggling to get half-decent brightness with 9Vs.

( Photos )

A long time ago, during Makevember I made a galvanised coated garden wire shamrock, for use as a sign at events. Here it is at Congress. To make it I printed the shape I wanted on A4 paper, put that on top of some cardboard, and used a pattern tracing wheel to transfer the outline to the cardboard. Then I cut the cardboard along that outline. And used pliers to bend and shape the wire to follow the outline of the cardboard shape. Including some feet so it could stand.

( Process )

Lit up LED shamrock sign, brightest setting
Photo by chebe

I find myself, like many of us, sitting at my desk a lot. I sit there for work. I sit there again for the many video and/or voice socials that have been set up. I sit there to play games or watch films. I even clear off the computer stuff and sit there to solder and work on projects. I am, in fact, sitting there now as I write this. So basically, I sit there a lot. And it got so that I found it difficult to know what time it was, whether early or late, start of the day, or end. I know, I thought, possibly aloud, no-one will ever know, I need a clock.

But I didn't want to go buying lots of unnecessary things, or wait until my usual suppliers were back in full swing. So I dug around in the piles of boxes that comprise my electronics stash. Back at GaelHack (seven years ago) I started on a clock, but it never left the breadboard. I dusted that off, and found most of what else I needed.

( Making it all fit together )

Given the purpose of the device, and age of most of the components, I had half a mind to refer to this as a Time Capsule, but Time Cuboid seems more self-explanatory.
Overall it looks something like this;

Time Cuboid, on
Photo by chebe