‘Tis the season for holiday hacks, and [Ben Emmett] is here to remind us that we don’t necessarily need a fancy microcontroller in order to make flashy fun things happen.
Take this Christmas tree for example, which uses a 555 timer and a CB4017 decade counter in order to drive some blinking LEDs. The ICs are through-hole, making the circuit fairly accessible to new players, but there are a few SMD components that need soldering as well. (More on that later.)
Here, the 555 acts like a clock and drives a square wave. Using the clock as input, the decade counter toggles the output pins one after the other, driving the LEDs to blink in turn. Since there are only eight lights, there is a pause in the light-up pattern, but that could be fixed by wiring decade counter output #9 to the reset pin.
Although function was the main focus circuit-wise, [Ben] managed to lay the traces in the shape of a Christmas tree, which looks great. Having done a similar project in the past, he discovered that the craft cutting machine prefers thick traces and wider spaces between them. This is largely why [Ben] chose to use through-hole ICs.
After laying everything out in KiCad, [Ben] exported the copper layer image for use on the cutting machine. Once it was all cut out, he put it on transfer tape to weed out the extra copper, and get the traces onto cardstock, the final substrate.
This is such a fun project, and we love that the CR2032 that powers it also acts as the stand in its vertical holder. Hit up GitHub if you want to make one for yourself. Want something even more 3D? Check out this hollow tree we saw a few years ago.
This should be simpler and easier to built using a thin epoxy etched board, it’s translucent and it’s much stronger than cardboard.
Congrats for using a 555 in place of a µC !
You clearly did not understand the assignment.
A deviant 555 for this simple task? It should of course be a 2 transistor oscillator!
In fact since gain is not to important he should grow his own silicone and dope it in a toaster oven.
I chose card stock paper because it was readily available and is very easy to work with, but the possibilities are endless with adhesive copper traces.
Very neat indeed!
Utterly gorgeous piece of work. It almost looks like art (not just the tree but the parts in the centre and even the blue LED, on white with black parts and copper wiring) really nice pallette.
pff. I could have done this with a raspberry pi 5…
Got an Xmas ornament kit for the kids at the Fab Lab. Had a tiny SMT 8-legger in it which I assumed was an ATTiny. Surprise! It’s a 555.
[Sniff Sniff] Who reminisced?
CB4017? Is that a typo? Didn’t it used to be called the CD4017?
Good catch. I had the typo in my original post which is probably why they have it as “CB4017” on Hackaday. I just updated my post to the correct name, “CD4017”.
For those looking for higher integration there is the CD4060 that has the 555 built in (at least for clock generation). You can make these run slowly enough to make a visible pattern easily enough.
Fun project, well done 👍