POV On The Flipper Zero

May 23, 2025 by Lewin Day 1 Comment

The Flipper Zero can do all kinds of neat stuff, like helping you cut keys or decode various radio transmissions. However, until now, it hasn’t been particularly adept at persistence of vision tasks. The LightMessenger was designed for that very purpose, and [Derek] recently wrote up a deep-dive into the interesting gadget.

The LightMessenger is a hardware add-on module developed by LAB401 in collaboration with [TIX LE GEEK] for the Flipper Zero. In persistence-of-vision mode, you can plug it in via the GPIO header and display messages in the air by shaking it around. Even better, you can do so in color, with a height resolution of 16 pixels—meaning you can display some nice text or basic graphics. You can key in different text or select and edit bitmaps using the utility on the Flipper screen itself. There’s even a simple flashlight mode, because why not?

In the second part of [Derek]’s write-up, he also goes into detail on the development and manufacturing process for the device.

Files are on GitHub for the curious. We’ve gone over the basics of POV projects before, too.

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RP2040 Spins Right ‘Round Inside POV Display

April 25, 2025 by Tyler August 3 Comments

Sometimes, a flat display just won’t cut it. If you’re looking for something a little rounder, perhaps your vision could persist in in looking at [lhm0]’s rotating LED sphere RP2040 POV display.

As you might have guessed from that title, this persistence-of-vision display uses an RP2040 microcontroller as its beating (or spinning, rather) heart. An optional ESP01 provides a web interface for control. Since the whole assembly is rotating at high RPM, rather than slot in dev boards (like Pi Pico) as is often seen, [lhm0] has made custom PCBs to hold the actual SMD chips. Power is wireless, because who wants to deal with slip rings when they do not have to?

The LED-bending jig is a neat hack-within-a-hack.

[lhm0] has also bucked the current trend for individually-addressable LEDs, opting instead to address individual through-hole RGB LEDs via a 24-bit shift-register. Through the clever use of interlacing, those 64 LEDs produce a 128 line display. [lhm0] designed and printed an LED-bending jig to aid mounting the through-hole LEDs to the board at a perfect 90 degree angle.

What really takes this project the extra mile is that [lhm0] has also produced a custom binary video/image format for his display, .rs64, to encode images and video at the 128×256 format his sphere displays. That’s on github,while a seperate library hosts the firmware and KiCad files for the display itself.

This is hardly the first POV display we’ve highlighted, though admittedly it isn’t the cheapest one. There are even other spherical displays, but none of them seem to have gone to the trouble of creating a file format.

If you want to see it in action and watch construction, the video is embedded below.

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Turn Your Phone Into A POV Hologram Display

February 8, 2025 by Al Williams 17 Comments

It seems obvious once you think about it, but if you can spin your cell phone and coordinate the display with the motion, you can create a 3D display. [Action Lab] had used such a setup to make a display that you could view from any angle. After he showed it, a viewer wrote him to mention that if you spin the picture at the same rate, it will appear in 3D. The results look great, as you can see in the video below.

The spinning mechanism in this case is an inexpensive pottery wheel. Whatever you use, though, you need a way to match the speed of the graphics to the speed of the phone’s rotation. For this example, there are just a few pre-spun 3D models on a website. However, creating your own viewer like this wouldn’t be that hard. Even more interesting would be to read the phone sensors and spin the image in sync with the phone’s motion.

We keep hearing about awesome commercial 3D stuff coming out “any day now.” Meanwhile, you can always settle for Pepper’s Cone.

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2024 Business Card Challenge: POV Fidget Keeps Your Info In Their Hands

June 28, 2024 by Kristina Panos 4 Comments

So what if we’re halfway through 2024? People who needed to fidget all along still need something to do with their hands. So why not hand them a solution with your information on it?

Not only will this spin nicely, the spinning action will use magnets to energize PCB coils and light up LEDs for some persistence of vision action. Designing the PCB was easier than you might imagine thanks to KiMotor, a KiCad plugin to automate the design of parametric PCB motors.

Mechanical testing went pretty well with the bearings and magnets that [mulcmu] had on hand, along with a scrap PCB as the sacrifice. Although a bit difficult to hold, it spins okay with just the bearing and the shaft. Once the boards arrived, it was time to test the electrical side. So far, things are not looking good — [mulcmu] is only getting a few tens of mV out of the rectifier — but they aren’t giving up hope yet. We can’t wait to see this one in action!

Hurry! This is the last weekend to enter the 2024 Business Card Challenge! Technically you have until Tuesday, July 2nd, but you know what we mean. Show us what you’ve got!

BikeBeamer Adds POV Display To Bicycle Wheels

June 11, 2024 by Bryan Cockfield 16 Comments

Unless you’re living in a bicycle paradise like the Netherlands, most people will choose to add some sort of illumination to their bicycle to help drivers take note that there’s something other than a car using the road. Generally, simple flashing LEDs for both the front and the rear is a pretty good start, but it doesn’t hurt to add a few more lights to the bicycle or increase their brightness. On the other hand, if you want to add some style to your bicycle lighting system then this persistence of vision (POV) display called the BikeBeamer from [locxter] might be just the thing.

The display uses four LED strips, each housed in their own 3D printed case which are installed at 90-degree angles from one another in between the spokes of a standard bicycle wheel. An ESP32 sits at the base of one of the strips and is responsible for storing the image and directing the four displays. This is a little more complex than a standard POV display as it’s also capable of keeping up with the changing rotational speeds of the bicycle wheels when in use. The design also incorporates batteries so that no wires need to route from the bike frame to the spinning wheels.

This is an ongoing project for [locxter] as well, meaning that there are some planned upgrades even to this model that should be in the pipe for the future. Improving the efficiency of the code will hopefully allow for more complex images and even animations to be displayed in the future, and there are also some plans to improve the PCB as well with all surface-mount components. There are a few other ways to upgrade your bike’s lighting as well, and we could recommend this heads-up headlight display to get started.

POV Digital Clock Is The Literal Sands Of Time

May 9, 2024 by Dan Maloney 9 Comments

Sand has been used to keep track of the passage of time since antiquity. But using sand to make a persistence of vision digital clock (English translation) is something altogether new. And it’s pretty cool, too.

The idea behind the timepiece that [Álvaro Gómez Giménez] built is pretty simple drop a tiny slug of fine sand from a hopper and light it up at just the right point in its fall. Do that rapidly enough and you can build up an image of the digits you want to display. Simple in concept, but the devil is in the details. Sand isn’t the easiest material to control, so most of the work went into designing hoppers with solenoid-controlled gates to dispense well-formed slugs of sand at just the right moment. Each digit of the clock has four of these gates in parallel, and controlling when the 16 gates open and close and when the LEDs are turned on is the work of a PIC18F4550 microcontroller.

The build has a lot of intricate parts, some 3D printed and some machined, but all very carefully crafted. We particularly like the big block of clear plastic that was milled into a mount for the main PCB; the translucent finish on the milled surfaces makes a fantastic diffuser for the 96 white LEDs. The clock actually works a lot better than we expected, with the digits easy to make out against a dark background. Check it out in the video below.

Between the noise of 16 solenoids and the sand getting everywhere, we’d imagine it wouldn’t be a lot of fun to have on a desk or nightstand, but the execution is top-notch, and an interesting and unusual concept we haven’t seen before. Sure, we’ve seen sandwriting, but that’s totally different. Continue reading “POV Digital Clock Is The Literal Sands Of Time” →

Tiny POV Turns Right Round For Volumetric Fun

December 3, 2023 by Dan Maloney 13 Comments

Just when you think the POV thing has run out of gas, along comes [mitxela] to liven things up. In this, he’s taken the whole persistence of vision display concept and literally spun up something very cool: a tiny volumetric “electric candle” display.

As he relates the story, the idea came upon him on a night out at the pub, which somehow led to the idea of an electric candle. Something on the scale of a tea light would fit [mitxela]’s fascination with very small and very interesting circuits, so it was off to the races. Everything needed — motor, LIR2450 coin cell, RP2040, and the vertical matrix of LEDs — fits into the footprint of the motor, which was salvaged from a CD drive. To avoid the necessity of finding or building a tiny slip-ring, he instead fixed everything to the back of the motor and attached its shaft to a Delrin baseplate.

The 8×10 array of surface-mount LEDs stands atop the RP2040 with the help of some enameled magnet wire, itself a minor bit of circuit sculpture. There’s also a 3D-printed holder for a phototransistor and IR LED, which form a sensor to trigger the display; you can see [mitxela] using a finger to turn the display off and move it back and forth. It goes without saying that these things always look better in person than they do in stills or even on video, but we still think it looks fantastic. There’s also a deep dive into generating volumetric data in the write-up, as well as an unexpected foray into the fluid dynamics calculations needed to create a realistic flame effect for the candle.

All in all, this is a fantastic if somewhat fragile project. We love the idea of putting this in a glass enclosure to make it look a little like a Nixie tube, too.

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