Christmas Lights 2024

It’s become something of a tradition at this point that each year I continue to build upon the interactive Christmas lights which I started in 2020.

Previous iterations:

• 2020
• 2022
• 2023

Now that my kid is walking, the baby bouncer control I added last year is redundant, but is given me the idea of continuing to build upon the lights following his progress stages.
So this year I purchased a Playstation dance mat.

The single board computer that I have been using is pretty much tapped out in terms of resources – trying to add a USB hub in order to connect the controller pulled too much power, so in order to do that would mean having another powered USB socket (currently there are 3, which all powered from a single wall socket, 3 port USB charger)

However the way that I have developed the control software is that it is ultimately a small web server on the local network.

Therefore I can connect the dance mat to a different machine then just have it control the lights over the network. It’s perhaps not the most optimal way of doing things, but is ultimately a temporary installation for a couple of weeks.

To connect the dance mat, I am using a Playstation to USB adapter (it’s a PS2 dance mat).

This shows up under lsusb, and using the details taken from there I can connect it using udev, following the same method that I used in order to connect the treadmill from a different project.

 

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Memory Box with lid-triggered audio

After having our son, my partner wanted me to make her a memory box where she could keep all the trinkets and keepsakes from his birth.

As it is something of an old stereotype that such things would be kept in an old shoe box, I wanted to mimic that aesthetic.

The box is made from iroko, sides of approx 1cm, joined with box joints.
The base is simple hardboard, rebated into the sides.

I didn’t really want to add hardware such as hinges as I felt it would detract from the shoebox aesthetic, so I opted for a simple lift off lid.

The lid itself is made from a thicker piece of iroko, with trim added around the edges.

In order to provide a good friction fit, a piece of plywood, wrapped in t-shirt fabric, matching the boxes internal width and depth was added to the lid. This holds the lid on without rattling around, and incidentally hides the “bonus feature” of the box.

The bonus feature

Of course I can’t do anything normal like just make a box.

During his first few weeks, whenever our son sneezed, he would follow it up with a little noise that sounded like he was saying “oh..”. Of course it was incredibly cute and a memory we want to cherish forever.

What my partner didn’t know at the time, is I had managed to catch this on video, and I wanted to surprise her with it. 

A few years ago (around 2015-2016 I think), Sainsburys brought out a Christmas biscuit selection box which included a gadget for recording a message that would play when the biscuit tin was opened.

Somewhere along the line somebody I know must have got one, I scavenged the gadget from the tin once it was empty, and it spent the past few years sat in my electronics junk drawer, waiting for a project to be used in.

 

 

The circuit board is clearly designed as a disposable product – it is powered by 3 button cell batteries, which are riveted to the PCB itself. Whatever microcontroller powers it is hidden under an epoxy blob, and the only other notable features are a small microphone, speaker, a light dependent resistor (which is how it detects if the box is opened), and a small switch used to start and stop recording.

First thing to do was to drill out the rivets and get rid of the dead batteries.
Rather than replace them with more button cells, I opted for wiring in a AAA battery holder, I just had to follow the PCB traces and connect it at the right point.

 The microphone is pretty much as crap as you would expect for something of that size in a ostensibly disposable product, so I needed a better way to record the audio.

To do that I replaced the microphone with a 3.5mm jack and coupling capacitor. Once I’d copied over the recording, I removed that as well to save space, and also removed the record button to avoid overwriting.

 

Then it was simply a matter of hiding the electronics in the box. This was done by carving out a hollow in the middle of the lid. The ‘inner lid’ of plywood that was also used to create a friction latch, added sufficient depth to the lid in order to hide the battery and PCB.

The underside of the lid with hollow for PCB/battery and speaker.

The t-shirt fabric that covered the inner lid also hid the circuitry, while also allowing enough light to pass through to activate the recording.

Krups “Espresso Piano” XP521040 coffee machine repair

Since repairing the Dolce Gusto pod coffee machine a few years ago, I upgraded to a proper espresso machine, The Krups “Espresso Piano” XP521040.

It was another freebie hand-me-down from a relative who no longer wanted it, so I have no particular opinion on whether it’s a great machine compared to the competition or anything like that – it’s merely a step up from using a pod machine (with or without re-usable pods).

The problem
A while back it started acting a bit weird – especially if I was making more than one coffee – it would seemingly enter what I thought was a cleaning cycle.
It just keep pumping water out into the drip tray until I switched it off at the mains.

More recently it failed more completely. As soon as the machine was switched on at the wall (even if the machine had not been switched on by it’s own power button), it would start pumping water into the drip tray – the only way that the pump could be switched off was at the wall socket.

Diagnosis
Starting by opening the machine up from the bottom, I quickly found the controller board. 

For a consumer product, the circuit board is surprisingly well labelled.
There are a number of braided wires, connected with spade type connectors.

After a bit of probing around, I noticed that the PCB had a slight scorch mark at the base of one component. It was very small, I actually didn’t notice anything during the initial investigation - it was only when I’d just about given up and was packing away everything to dispose of that I spotted it.

The scorch mark around the leg of the failed component

 

 

 

 

 

 

 

 

 

 

 

The component in question is a BT134. This is a triac, and it is connected to the pad with the spade connector labelled “pump” – So it seemed a likely culprit.

Tracing the connections about the machine appears that the pump has a direct AC connection, so my guess as to what happened is that the component failed and it’s failure state effectively held it open instead of in a “switched off” state.

This does explain why the pump was active only with mains power, regardless of the rest of the machines state.

The fix
The fix itself was plenty straight forward. I sourced a replacement BT134, I swapped it out, which requires no more than a little bit of soldering.

Putting it all back together, I tested it and it works fine.

There’s nothing more to it really than that, I just want to write up and publish this in case it helps anyone else who may be having similar issues with our machine. But as always, these posts should be treated as a diary of what I did, and are in no way a how-to or guide. I am by no expert, what you do with information I provide is at your own risk.

Hardwood slim line LED panel light fitting with accent lights

I recently purchased a pair of low profile LED ceiling lights from a charity auction on Ebay.

It seemed like the kind of thing that I’d find a use for eventually, and it was for a good cause.

After buying I had a message from the seller to tell me that they only had one driver for the two panels – I went ahead with the purchase because at the end of the day I wasn’t expecting them to be new and pristine from a charity auction.

My curiosity was piqued when they arrived. I noticed another label sticking out from underneath the address label. I peeled it back, and revealed an Amazon delivery label to a different address.

Initially I figured perhaps it was an Amazon returned item – one of the drivers was missing, therefore the original purchaser returned it, and it was sold on to the charity as one of those wholesale return pallets that you see advertised.

I did also think that the wires on the mains side of the LED driver seemed a little bit thin. However I tested it with those panels and they actually seemed to work okay, so I didn’t think much more of it.

Losing faith

So, I started to put together a project plan to make a light fitting with them.

I wanted to add in a few extra accent lights but everything I had was 12v, and the light fittings driver was 18v. While I was mulling over options – adding in a separate transformer, the space and heat issues to work round, etc. I noticed a couple of other things.

The case of the driver seems to have fake screw heads stamped on them. Not in itself a problem, but kind of sketchy.

And the panels themselves are stamped with 18w, not 18v.

The output of the driver says 9-18v at 300ma.

W=V*A.

There’s no way that if those panels are 18w, the driver can provide enough power to them.

This made me rethink my theory on the background of these lights.

Having a look on Amazon I can see very similar products, with identical looking drivers – the only difference being that the outputs are rated differently.

My guess is that this set of lights came with incorrect drivers, and the original purchaser damaged one whilst trying it.

It’s only a theory and not enough to make a claim against, it ultimately is enough to destroy my faith in these lights and make me not want to use them as they are.

Rebuilding the electronics

I had built the design around the size of these panels, so I decided to rip out all of the electronics.

On doing so I realized that the panels were just flexible LED strip edge mounted to a diffuser.

I swapped out the LED strip that was there with some white 12v strip LEDs. I had to trim about a millimeter off the sides of the diffuser in order to account for the slightly larger LEDs.

In an initial test the LED light was quite patchy, so I took the diffuser from the second light and doubled up. This makes a notable difference.

To drive the strip I’m using a regular RGB LED control box.

Initially my choice of this was simply because it was available and had a small profile so would fit well in the fitting.

However this also gave me the idea I could run the accent lighting and the main light on different color channels, allowing them to be controlled separately. It would also allow me to dim the light.

The design

Because I don’t want to carve out my ceiling to flush fit the panel I planned to build a small mitred frame, with another frame mounted at forty five degrees behind it. The back frame would contain some accent lights, with the front frame housing the main light fitting.

the fitting needed to fit in with the of our lights in the room, so I disassembled the original fitting and spray painted it black.

For the wood frame I opted to use zebrano.

The frames are simple squares with 45 degree mitres, and a 2mm deep by 10mm wide rebate to fit the light fitting frame flush with the surface.

The back frame was turned at a 45 degree angle, and screwed to the front frame.

The back frame also had a pair of key hole plate mounted to the back, which will be used for connecting to the ceiling.

Accent Lighting

Rather than cut up the filters from the second light, I opted instead to use a stack of filters from an old PC monitor. It was simply a case of measuring out the triangles, cutting them and then gluing them in place with hot glue.

Each corner would have a single segment of white LED strip (3 LEDs per corner). These would be connected in series and then connected to the RGB LED control box, on a different color channel to the main light, allowing them to be used independently.

The rest of the electronics

The IR receiver from the control box sticks out behind the front frame, so it is not visible from ground level, but catches enough reflected light from the ceiling to function.

However, this didn't last long and soon found itself wrapped in black tape because what I didn't realise at the time was that the IR receiver worked on the same encoding as our TV remote and we soon bored of having the lights change as we scrolled through TV guide menus.

PSU

The power supply is provided by an AC-DC “wall-wart” – I had to be quite selective in which one I picked to fit within the frame. The one I opted for had a removable face plate which allowed me to remove the socket pins and wire directly into.

The end result