In the world of big-box retail, December 26th is a very special day. The Christmas music playing on the overhead speakers switches back to the family friendly Top 40, the store’s decorations get tossed in the compactor, and everything that’s even remotely related to the holiday is put on steep clearance. No more money to be made on the most commercialized of all holidays, so back to business as usual.

Given how popular they are, I was surprised to see a lone Home Accents Holiday Multi-Color Light Projector on the clearance rack at Home Depot for around $14 a few days after Christmas. This was a 75% price reduction from normal MSRP, and right in that sweet impulse-buy price range. Let’s see what’s hiding inside!

The red laser is mounted in the smaller heatsink, positioned 90 degrees from the other lasers. This positioning is necessary for the beam combiner (the small angled piece of glass visible in the center) to send both the red and green beams out of the same aperture.

The attentive reader might notice from this picture that the lasers are way out of focus: at 3 meters, the spots looked as large as dinner plates.

Once focused, it becomes pretty clear that these lasers are quite a bit more powerful than the < 5 mW listed on the product’s warning sticker.

In fact, once the blue laser was focused I was easily able to burn pieces of paper and punch holes in black plastic.

As for the green laser, it is at least twice as bright as my green laser pointer which is labeled as 50 mW.

If your biggest take-away from this post is that the Home Depot is selling a 440 nm laser you can use to burn stuff, I certainly don’t blame you.

For $14, I’ve got to say this is a pretty decent score:

From the optics section we’ve got a nice little geared motor, a beam combiner, and four optical gratings. Three laser modules and a driver board than can power any combination of them at once. Two heatsinks, one with an integrated temperature sensor. A tiny little heat pad, and finally a rugged looking 5V/2A adapter.

‘Tis the season to stick Arduino’s in festive places, and what better place than a Christmas tree! In this project, we are going to be making a Christmas tree that can sing a bunch of different Christmas songs and light up in conjunction with the music! Attached is an audio file of the tree in action to give you an idea of what it sounds like.

Use Arduino to run a spectacular Christmas light show.

Control any of the 55 RGB LEDs on the tree, let Santa twerk for you, control a model railroad, or display custom text on an LED dot matrix.

Isä ja tytär kietoivat kotinsa ympärille yli 20 000 lamppua – “Tässä käy välillä sellainen autorundi, että hyvä kun sekaan mahtuu”
Samu Hohdin taloa on käyty ihmettelemässä jopa linja-autolla.
https://yle.fi/uutiset/3-9980954