Planet Arduino

Hackaday readers have certainly seen more than a few persistence of vision (POV) displays at this point, which usually take the form of a spinning LED array which needs to run up to a certain speed before the message becomes visible. The idea is that the LEDs rapidly blink out a part of the overall image, and when they get spinning fast enough your brain stitches the image together into something legible. It’s a fairly simple effect to pull off, but can look pretty neat if well executed.

But [Andy Doswell] has recently taken an interesting alternate approach to this common technique. Rather than an array of LEDs that spin or rock back and forth in front of the viewer, his version of the display doesn’t move at all. Instead it has the viewer do the work, truly making it the “Chad” of POV displays. As the viewer moves in front of the array, either on foot or in a vehicle, they’ll receive the appropriate Yuletide greeting.

In a blog post, [Andy] gives some high level details on the build. Made up of an Arduino, eight LEDs, and the appropriate current limiting resistors on a scrap piece of perfboard; the display is stuck on his window frame so anyone passing by the house can see it.

On the software side, the code is really an exercise in minimalism. The majority of the file is the static values for the LED states stored in an array, and the code simply loops through the array using PORTD to set the states of all eight digital pins at once. The simplicity of the code is another advantage of having the meatbag human viewer figure out the appropriate movement speed on their own.

This isn’t the only POV display we’ve seen with an interesting “hook” recently, proving there’s still room for innovation with the technology. A POV display that fits into a pen is certainly a solid piece of engineering, and there’s little debate the Dr Strange-style spellcaster is one of the coolest things anyone has ever seen. And don’t forget Dog-POV which estimates speed of travel by persisting different images.

[Thanks to Ian for the tip.]

This is the seventh post in my series on how I setup my christmas lights

Links to rest of series:

• Post 1 – The controllers
• Post 2 – The megatree
• Post 3 – Arches, candy canes, small spiral trees and large spiral tree
• Post 4 – Nativity Scene
• Post 5 – Windows, Singing Tree and tune-to sign
• Post 6 – Palm trees, carport and roofline
• Post 7 – LED Shirt

This post focuses on my LED shirt.
To see it in action check it out on youtube

My LED shirt is actually an apron I wear under a plain t-shirt (so the shirt can still be washed ) It is made from a 5m led strip running on 5V The strip is 150 individual WS2811 pixels split into 15 sections of 10 pixels. The entire strip is connected to a Pixel-Wifi (ESPPixelstick clone) powered by a small USB battery. The Pixel-Wifi support E1.31 so the shirt is treated as a small matrix in my display. I made the apron from some fabric scraps my wife had – the strips are then sewn onto the apron with some electrical tape keeping them in spot.

This is the seventh post in my series on how I setup my christmas lights

Links to rest of series:

• Post 1 – The controllers
• Post 2 – The megatree
• Post 3 – Arches, candy canes, small spiral trees and large spiral tree
• Post 4 – Nativity Scene
• Post 5 – Windows, Singing Tree and tune-to sign
• Post 6 – Palm trees, carport and roofline
• Post 7 – LED Shirt

This post focuses on my LED shirt.
To see it in action check it out on youtube

This is the sixth post in my series on how I setup my christmas lights

Links to rest of series:

• Post 1 – The controllers
• Post 2 – The megatree
• Post 3 – Arches, candy canes, small spiral trees and large spiral tree
• Post 4 – Nativity Scene
• Post 5 – Windows, Singing Tree and tune-to sign
• Post 6 – Palm trees, carport and roofline

This post focuses on the palm trees, carport and roofline

We have three large palm trees in the yard – the middle one supports the mega tree while on the two other I have attached two 5m strips (split into four 2.5m sections) to each tree.

Along the guttering I have attached pixel strip. The strip is cable-tied to electrical conduit (to keep it straight) and the conduit connects to clips attached to the underside of the guttering.

I the carport I have attached strips via cable-tie. One strip for each cross-member (four in total)

This is the sixth post in my series on how I setup my christmas lights

Links to rest of series:

• Post 1 – The controllers
• Post 2 – The megatree
• Post 3 – Arches, candy canes, small spiral trees and large spiral tree
• Post 4 – Nativity Scene
• Post 5 – Windows, Singing Tree and tune-to sign
• Post 6 – Palm trees, carport and roofline
• Post 7 – LED Shirt

This post focuses on the palm trees, carport and roofline

This is the fifth post in my series on how I setup my christmas lights

Links to rest of series:

• Post 1 – The controllers
• Post 2 – The megatree
• Post 3 – Arches, candy canes, small spiral trees and large spiral tree
• Post 4 – Nativity Scene
• Post 5 – Windows, Singing Tree and tune-to sign
• Post 6 – Palm trees, carport and roofline
• Post 7 – LED Shirt

This post focuses on the windows, the singing tree and my tune-to sign

This is the fifth post in my series on how I setup my christmas lights

Links to rest of series:

• Post 1 – The controllers
• Post 2 – The megatree
• Post 3 – Arches, candy canes, small spiral trees and large spiral tree
• Post 4 – Nativity Scene
• Post 5 – Windows, Singing Tree and tune-to sign
• Post 6 – Palm trees, carport and roofline

This post focuses on the windows, the singing tree and my tune-to sign

The windows each have a string of 50 pixels hanging up around them. They are connected to the window frame via cable ties to staples. The staples stay in all year so put up/take down just requires adding/removing the cable ties

The singing tree is made from 233 pixels pushed through a sheet of corrugated plastic bought from Bunnings. I drew out the shape of the tree then used a 12mm hole-punch to make suitable holes for the pixels to fit in. I built a small frame around the sheet so I could space it out from the wall. The frame hangs on the wall using two eyelets to some hooks drilled into the brick itself.

The tune-to sign is made from three Freetronics DMD displays (32×16 red leds each).

Controlling the tune-to sign is an old arduino strapped to the back of the beam.

This is the fourth post in my series on how I setup my christmas lights

Links to rest of series:

• Post 1 – The controllers
• Post 2 – The megatree
• Post 3 – Arches, candy canes, small spiral trees and large spiral tree
• Post 4 – Nativity Scene
• Post 5 – Windows, Singing Tree and tune-to sign
• Post 6 – Palm trees, carport and roofline
• Post 7 – LED Shirt

This post focuses on the Nativity scene at the side of the yard.

This is the fourth post in my series on how I setup my christmas lights

Links to rest of series:

• Post 1 – The controllers
• Post 2 – The megatree
• Post 3 – Arches, candy canes, small spiral trees and large spiral tree
• Post 4 – Nativity Scene
• Post 5 – Windows, Singing Tree and tune-to sign
• Post 6 – Palm trees, carport and roofline

This post focuses on the Nativity scene at the side of the yard.

This is the finished nativity scene. The stable is made from two lengths of wood cut and painted accordingly. The cutouts (Angel, Mary, Joseph, Jesus and two dinosaurs) are all made from marine-ply painted white.

Here is a close-up of two of the cutouts – an Apatosaurus and a Triceratops (chosen by my five year old and three year old receptively. They were made by drawing out the shape on a piece of marine-ply, cutting out with a jigsaw and then painting white.

To light the nativity scene I bought a cheap worklight and replaced the innards with three 12V pixel modules.

This is the third post in my series on how I setup my christmas lights

Links to rest of series:

• Post 1 – The controllers
• Post 2 – The megatree
• Post 3 – Arches, candy canes, small spiral trees and large spiral tree
• Post 4 – Nativity Scene
• Post 5 – Windows, Singing Tree and tune-to sign
• Post 6 – Palm trees, carport and roofline

This post focuses on the arches along the front, the five candy canes and the small spiral trees