Confronted with the issue of finding a use for his mounting pile of junk electronics, [Rue] set out to build a persistence of vision device using a hardware state machine. We have a suspicion that his original link may go down if there’s too much traffic so here’s a cached link just in case.

Any board that is MSC-51 or MCS-48 based would have worked for his purposes. This is because the addressing scheme of the hardware makes it an easy hack. The image above shows him cutting off the processor from this board. It was chosen because of a 74HC373; it was a mistake at first but since it’s pin compatible with the 74HC374 that he needed a simple swap did the trick. From there a clock source was added, and the address information necessary to display the message was burned into an EEPROM.

Step twelve of his writeup shows a Morse Code message created by attaching the board to a broomstick and twirling it around in an arc. We took  just a minute to decode the message and believe it’s a shout-out to Hackaday. Nice, thanks for reading [Rue]!

[Ryan]‘s cylinder POV display is an amazing piece of work. Right now it’s impressive sitting on his workbench, but we’re sure it would be astonishing hanging above the middle of a dance floor. There are 64 RGB LEDs on this display and they’re certainly bright enough to liven up any space.

Power is provided through a slip ring. The ground is connected to the shaft of the motor [Ryan] picked up at an auto parts store. It’s an efficient way to do things, but the display can only be controlled by whatever image is stored in the ATMega1284′s flash memory. [Ryan] admits this isn’t an ideal setup so he’s working on a ZigBee or Bluetooth connection.

We’ve seen some amazing spinny POV cylinders, but [Ryan]‘s build looks amazingly professional. All the board files, schematics and code are uploaded, as well as an image converter for BMPs and PNGs. Check out the demo after the break.

[Ch00f] spent some serious time figuring out how the Icebreaker POV toy works. This is a pretty cool device about the size of a toothbrush holder. It’s in a clear plastic case, which lets the row of 32 surface mount LEDs shine through. But making light isn’t their only function. You can use the device to scan in a high-contrast design, then ‘play it back’ using the persistence of vision display properties of the LED strip.

Perhaps the biggest question on [Ch00f's] mind was how the sensing is done. He made a series of observations, then started monkeying around with the LEDs to investigate them. It seems that one LED is lit up while the ones around it are used as light sensors. This becomes more confusing once he realized that the display was multiplexed.

His write-up includes a collection of schematics that can be pieced together to conceptualize the entire circuit. The image above was taken during this process, using an LED to check the connections on a part. This let him prove that it’s an N-channel MOSFET. He plans to take what learned and roll it into his own project.

[via Reddit]

So we saw this tip come in and thought–oh, another POV device. We watched the video (embedded after the break), took a sip of coffee, then almost sprayed the beverage all over the computer when we realized that this uses a diy sensor to synchronize the POV image.

[Ch00f] came up with the idea for the sensor after seeing a similar implementation on a commercial POV toy. Instead of using a proper accelerometer to sense the motion, the toy uses a plastic bead in a channel. When you move the body of the toy the bead rolls to one end or the other, covering or exposing a reflective sensor.

A similar sensor is used here. A drinking straw servers as the channel, with a paper-covered nylon screw as the bead. [Ch00f] cut a window in the bottom of the straw for his reflective sensor, then sealed each end with a wad of paper.

This method works, but not as well as he had hoped. It seems the refresh rate and timing of the particular sensor he’s using is rather poor. If it were replaced with one that is simply and IR LED and phototransistor (like the sensors from [Jack's] last video) he thinks it would work a lot better.

via Buildlounge.

We’re no strangers to POV time pieces around here, but something about them never gets old. Whether they use a ring of LEDs to draw clock hands, or an intricately cut HDD platter to replicate LCD segments, we love seeing them. [David] sent in this hard drive POV clock built by a fellow named [Kly], and it’s just beautiful.

[Kly’s] “Propeller” POV clock is named as such due to the design of the circuit board. The board is mounted on the HDD spindle, rotating much like an airplane’s propeller. The construction details are sparse, but from what we can find, it is based around a PIC32MX microcontroller, which is used to control the 66 SMD RGB LEDs mounted on the circuit board.

As you can see in the video below, the tightly packed LEDs result in some pretty amazing visuals.

Aside from watching the video below, be sure to swing by his Youtube channel for a handful of videos showing RGB POV clock in action.

[Augusto] wrote in to tell us about his keychain-sized persistence of vision project. He built the original prototype on some protoboard, using a PIC 16F627 to drive eight LEDs. Synchronization is managed by a tilt sensor on the board that starts the strobing to match the direction the board is traveling. This is a similar setup as the POV device that used an accelerometer, but it should be quite a bit easier to code for the tilt switch.

Once [Augusto] had the hardware dialed in he set to work laying out a surface mount design. The two AAA batteries were traded for a single 3V coin cell, which is on the back side of the board you see above. This is his first attempt at working with surface mount components and we think he did a great job. Check out the POV in action in the video after the break.

[Zach's] company is all about the safety and to reinforce those ideals they handed out POV display fans to each employee. “Being Safe is Cool”, get it? Gimmicky… yes, but now [Zach's] got a tiny little POV fan to hack. Although he may not have known it, this isn’t the first time we’ve seen this hardware. These fans were handed out as a promotion at Black Hat a couple of years ago and prompted some reverse engineering action. The message is stored on an EEPROM and there’s even a female programming header that makes it easy to write reflash it with your own messages if you know how to craft the data.

This is where the two products diverge. The older project uses a serial connection and PonyProg to dump and data. [Zach] first tried using his Bus Pirate to dump the data but after having no success he grabbed his Arduino and managed to get the job done. Once the message encoding protocol was worked out, he wrote a sketch to flash the EEPROM. So if you can get your hands on one of these the work has already been done. See [Zach's] custom messages in the video after the break.

But we’d like to see this taken to the next level. How about a wall-mounted device that waits for something, like an incoming email or tweet, then spins up the fan to display it?

A user named [BOcnc] on the rcgroups forums just posted his RGB POV helicopter blades.

The two blades are attached to the heli just as any other whirlygig. The electronics, though, are mounted underneath the blade with a battery pack. We covered a build last year that demonstrated weight added to a spinning blade won’t tear everything apart, but that build used only blue LEDs. This build is full color and makes us feel like we’re living in a cyberpunk future populated by Recognizers and Daft Punk.

The images are stored on an SD card that receives data from a USB port. The microcontroller is a PIC32, and from what we can assume from the schematics, the RPM of the blades is measured by an on-board hall effect sensor (don’t quote us on that, though). There’s no hope of a commercial release from [BOcnc], though. He can’t find anyone to manufacture the blades, and the entire build was too expensive. It sure looks pretty though, so check out the video of it after the break.

Last year, when [Alex] was asked by his friend [Martin] to help him out with building some LED POV modules for a race car, his response was a enthusiastic “YES!”

[Martin’s] goal was to involve fans more deeply in the race, so he decided that the POV modules would carry messages from fans on-board, printing them in the night as the race cars screamed around the track. The pair started prototyping and testing a design, wrapping things up shortly before this year’s 24 hours of Nürburgring.

The modules consist of an Arduino-compatible AVR, a GPS module, a 16-LED light bar, and the circuitry for driving the LEDs. While most of the components are pretty standard fare, the we don’t often see a GPS sensor built into a POV display. [Alex] says that the sensor is used to calculate the speed of the cars, ensuring a uniform font size.

They took their LED displays to the 24 hours of Nürburgring, where they were invited by Audi to install the modules on a pair of R8 Le Mans race cars. As you can see by the pictures on his blog and Flickr set, the POV units worked out nicely without having to stretch the camera exposure times too far.

If you’ re interested to hear a bit more about how the displays were built, check out this entry in[Alex’s] blog, where he goes through some additional details.

Update:[Alex] pointed us to the videos!

Hackaday reader [svofski] sent in a fantastic looking hard drive-based POV clock (Google Translation) created by a maker in the Sichuan province of China. The clock, like the one [svofski] built, relies on LEDs placed behind the spinning platter to create the POV effect.

Quite a few carefully placed cuts have been made to the platter, which make up the segments required to display both numbers and letters of the alphabet. This isn’t a simple 16-segment POV display however. The font uses a lot of sharp edges and odd segment lengths, so we’re guessing that quite a bit of care was taken in the production of this clock.

You can see a demonstration of the clock in the video embedded below, which shows off its ability to display numbers, text, as well as a handful of simple patterns. It looks like there are some details available on the designer’s site, however it is all in Chinese, and Google’s translation is questionable at best. If only we knew someone that could give us a hand with deciphering the inner-workings of this clock…

We see lots of persistence of vision projects around here, but we can’t recall any that involve a POV display facilitated by a living, breathing animal (humans aside, if you want to picky). [Michael] has a Miniature Pinscher that just loves to run and run…and run…in circles. Since she generally runs very fast and in large curves, he thought she would make a great POV device.

He has a small fleece “jacket” for his dog, and on it, he mounted a Lilypad Arduino, the associated power supply, and five bright white LEDs. Naturally, conductive thread was used to wire up the circuit, and after a bit of trial and error, things came together nicely.

With the vest complete, [Michael] unleashed his dog at the park, letting her run to her heart’s content. All the while, her vest was writing out [Cory Doctorow’s] “Makers” while he snapped some pictures.

We can’t think of a more appropriate text to write with LEDs in the night, but in the spirit of the book, we were hoping to see a circuit diagram or the project’s code posted. If he shares it, perhaps we could convince [Cory Doctorow] to run about the park in a vest, writing out [Michael’s] code in bright white LEDs!

We’ve already added the components needed to build [Rucalgary's] tiny POV device to our next parts order. The little device sets a new standard for tiny persistence of vision boards. Instead of relying on the user to find the best speed and timing for swinging the board around, [Rucalgary] used an accelerometer. This is the point at which we’d usually groan because of the cost of accelerometers. We’re still groaning but this time it’s for a different reason.

The accelerometer used here is a Freescale MMA7660. It’s an i2c device at a super low cost of less than $1.50. The reason we’re still groaning is that it comes in a DFN-10 package that is a bit harder to solder than SOIC, but if you’ve got patience and a good iron it can be done. An ATmega48 drives the device, with 8 LEDs and one button for input. On the back of the board there’s a holder for a CR2032 coin cell battery and a female SIL pin header for programming the device.

Check out the video demonstration embedded after the break. We love it that the message spells and aligns correct no matter which way the little board is waved.

[Thanks Paul]

We love spinning POV displays but have yet to build one to call our very own. This project might be the one that we end up building. It’s looks good and it’s the only persistence of vision display that comes to mind which can be built in twelve hours.

The spinning is taken care of by a PC fan. This actually helps with some of the calculations as this fan spins at a know RPM. That information, along with a bit of geometry, can be used to calculate the timer interrupts for syncing the display. A reference point for this device is provided by an IR receiver/emitter pair which is easy to wire up since you already need a voltage source for the fan itself. The rest of the hardware is pretty common: a battery holder is centered on the axis for proper weight distribution and protoboard houses the components such as a PIC 18F252, 74LS373 data latches, and the LEDs themselves. The circuit is wire-wrapped, and works like a charm as evidenced in the clip after the break.

[via Hacked Gadgets]

[Powder4u] wanted to make a persistence of vision display for his bicycle but with 50 cm of snow on the ground it’s hard to get out and ride right now. Instead he made this persistence of vision ski-pole accessory. We asked him to share some details and he obliged. It’s made using an Arduino compatible ATmega168, LEDs with resistors, and installed on some protoboard. The enclosure is a clear pencil case, which isn’t water tight but he’s tried to bolster that with some creative scotch tape placement. There’s no sensor to detect which direction the board is moving in so displaying alpha-numeric messages will have some issues, but as you can see he managed to display image data without issue.

We’re used to night skiing with floodlights along the slopes. This would be a fun little thing to have along with you on those dark lift rides.

This digital display is made from several analog clocks with thick hands. Together they make something of a 7-segment display, which can be used to display the time. It reminds us of the “Shared Time” installation we covered previously. [Thanks Drum365 via Anonimiss Files]

Quickly desolder lots of parts

[Rhys Goodwin] is grabbing parts from junk PCBs but he’s not using a rework station. Instead it’s a hot-air gun and a brisk tap on the bench to send the parts flying. Well, at least he’s not using a blow-torch like [Ben Heck] does.

Binary Hero

This bank of 8 toggle switches is the controller for Binary Hero, a geeky take on Guitar Hero. When you see a decimal number come down the screen set your toggle to the binary equivalent in time or the game will be over before you know it. [Thanks Fabien]

Quick fan POV

[GMG] took a small persistence of vision board and slapped onto an oscillating fan blade. Along with a couple of magnets on the safety cage this display is a persistence of vision hack you can pull off in an hour or two.

Speed up laser etching

[James] figured out a way to cut down on the time it takes to etch multiple copies of one item with a laser cutter. It doesn’t run the laser faster, but orients the pieces in a way that means less movement of the head while the laser is not on. Read through his article and see if this method can help you out when doing some CNC work.