How I dreamed of haipaning or the story of the “first” POV fidget spinner


It was mid-May, search engines explode from requests related to the so-called fidget spinners, Youtube is overwhelmed with videos about DIY spinners, the world is mired in the hype through these spinning designs.

Somewhere at the same time, a crazy thought came into my head, which shifted all the others to the side and, sitting on a pedestal, spoke: “You have to do a POV fidget spinner!”.

And this story began with a simple query in Google and subsequent surprise, no one has yet made such a device, it really cheered me up and motivated, passion as I wanted to make an electronic device to which the hands of Chinese engineers had not yet reached.

Keeping this fuse in me, I took a pencil and paper. First of all, I limited myself to the size of the case which gave me a certain freedom in the choice of components, but at the same time I would not go far beyond the ordinary spiner. Next was the most interesting - the assessment of optimal functionality and selection of a complete set.

The POV display clearly needs to be done on LEDs, and since our case is small, the size 0603 seemed optimal. The number of LEDs in the line was chosen based on the videos viewed on Youtube about various POV turntables.

I wanted to feed all this stuff from a Li-po battery with the ability to charge and benefit from the last project, I still had unnecessary MCP73831 chips, and the 3.7V and 250mAh battery was also lying idle, so I quickly closed the question.

It was a little more difficult to choose a controller and a sensor to determine the complete rotation of the spiner (at one point I even wanted to tinker and do everything on the accelerometer, but I realized that this was a brute force). There were 2 thoughts in my head - a Hall sensor or an optical sensor. But, having a quick look at the datasheets of the Hall sensors, I was surprised to find that from what I had on hand and what our “rural” radio parts store was selling there is no sensor that would work from 3-3.7V, but optical sensors with their fall on the LED in the 1.2V region they began to look more profitable.

When introducing a model of new infrared sensors into the circuit, I suddenly thought about one nontrivial question: “What am I going to output?”. The ten-minute Brainstorm gave the necessary minimum functionality for such a device. The variant with the harvested inscriptions and symbols was not particularly deliberated (since it was the most commonplace), also the option came immediately to deduce the number of revolutions of the spiner, well, the final idea was to make a time display.

The DS3231 real-time clock chip seemed appropriate - the case is planar, low, time shows, from 3-3.7V works well, okay, I ordered, we wait.

The controller decided to choose from the position better than the smaller and put the ATmega8 , the benefit of the ADC is on board, i2c for DS3231 is implemented, the legs are decent, the memory too. Components are selected, the scheme to make works did not arise.


Simultaneously with drawing the scheme, I frantically dreamed that I would be the first to make such an upgrade of the spinners and I would be able to say “take a little bit” and maybe even get a hundred other people who would be interested in my invention.

The scheme is simple, but the decision to make the board itself made the wiring process a bit more complicated, but for the first time I did a board with a size of 30mm x 20mm and LUT technology gave its limitations.

In parallel with the wiring, I made a model of a simple case with the necessary holes for the micro-USB connector, the power switch, a pair of optical sensors and buttons for minimal setup.

Why two optical sensors? Thinking over the concept, I decided to lay in the future the possibility of automatically determining where the hand of the person holding the spiner is now and to display the inscription in free space (at that time the position of the sensor from below didn’t bother me, although it was clear that it was more logical to place it on top okay, the prototype is still).

At about the same time as I made the board, I realized that I wanted to remake most of the whole scheme, I had an idea in my head using RGB LEDs and a variant with a Bluetooth module through which data could be sent to the spinner, but I’d like to do something That deducing characters and figures prevailed and I decided to leave these ideas for future versions of spiners.


After I soldered the elements into the board, with my old Soviet soldering iron, I immediately remembered that it was time to order the case. The lack of a personal 3D printer always depressed me, but the toad inside, which looked at a price tag of 30-50 thousand for a less-average printer, choked me harder and we agreed with her that I can only afford to buy a new soldering iron.

Electronics is ready, now the most interesting is the controller firmware. Having pretty much twisted, I put on weight the good old giant BH-10 programming connector and toggle switch in order to completely disconnect the power.

I’ll say right away that I killed 2 chips, the reason was inattention (I just forgot that I didn’t have a factory board with metallized vias and because of this mistake, the chips were fed incorrectly and the fusion bit firmware flashed with an error).

While there was a new batch of chips, I managed to remake the wiring a bit and made a new version of the board, clean and beautiful, and part of the tracks retired from the chip past. Also wrote a test firmware, which was supposed to display the line in a static position, and at the same time finalized the incoming body with a file and a scalpel.

A few days passed and I received new chips, blissfully sealed the first chip, rammed everything into the case and flashing the test firmware neatly brought the angular speed to this spiner; .

After a couple of minutes, I calmed down and stopped spinning in order to prolong this feeling. A few hours later, the firmware was written that already displayed a line of 8 digits, according to my calculations, the inscription was to occupy 120-130 degrees, and it turned out, but visually it was not very beautiful and I reduced the angle to a pleasant look.

Further, it was decided to find out with what speed my unbalanced miracle is spinning.

It is spinning weakly, but you need to consider that in this video the spinner is decently unbalanced, the overall load in the form of a toggle switch and BH-10 makes itself felt, although I tried to locate them optimally for the center of gravity.

The next step I wanted to see the time on this device and I clung to the datasheet on DS3231, for a couple of evenings I wrote a firmware code that allowed setting and displaying time. Zadono decided to check whether everything that I created into the case would fit.


It fit perfectly and even tightly closed the lid, well, of course everything was also unbalanced, but for the first sample it suited me, I even thought about making a housing with a different bearing size, which would create additional space for sealing with lead shot or something like that .

And here I am so pleased, thinking that in a few days I’ll finish the functionality of my brainchild and present it to the public as the world's first prototype POV-spiner, I decided to enter this phrase again in the search bar.

It was June 28, the first time a regular search query in Google drove me into depression. The first in the search results was a video on Youtube, where some American guy was already spinning a spinner in his hand, which also, like mine, displays revolutions per minute and all sorts of greeting inscriptions, and most importantly this video was uploaded to YouTube on June 25.

Spoiler header

Then there was another link where the guy set himself the goal of making a “pumped” POV spinner with RGB LEDs, an accelerometer and a mikruha for IoT, began to implement the idea on June 9 and already has a beautiful board with RGB LEDs on hand.

I can't help wondering how, after all, in one fairly short period of time (especially considering that the HYIP on spinners has been going on for more than a month), several people thought about one idea and began to frantically implement it, this is funny.

The workmanship of the American colleagues is much better, of course, it undermined my motivation to further refine this device. The idea that “they have already done everything more beautifully and more functionally” has smoothly shifted the past full of confidence and excitement. Yes, and a couple of other "first in the world" devices that were paused for the sake of this spiner, have not yet had time to create foreign colleagues in the shop, which means there is a chance that at least I will do them first.

P.S. Sorry for the quality of the video and photos, in the hands of only a Chinese phone.


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