Spinning LED Display




Introduction: Spinning LED Display

The Spinning light display uses a motor to spin the board at high speed while pulsing the lights to make patterns in the air as it zooms around. It is easy to build, easy to use, and fun to show off! It also has a header so that you can update the software on the chip to make it display text or different patterns.

This project was designed by microcontroled1204. You can get the kit from Gadget Gangster.  Build time is about 20 Minutes and it's an easy build.

Step 1: FAQ

How does it work?
The LED's on the PCB light up in a specific pattern. As the motor spins the board around, you're able to see the pattern - this is an example of the Persistence of Vision effect.

Does it take batteries?
Yes. The kit comes with a lithium cell battery to power the SX, but you'll need to provide 2 AA batteries to power the motor. The board is designed so you can mount it on other spinning things, like bicycle wheels, also.

Can I put it on something other than a motor?
Yes, the board has a set of holes on both ends, put a string or wire through the holes and you can tie the board to almost anything. I've tied it to my bicycle and it looks pretty cool.

What are the patterns?
You can see an example of the patterns that come pre-programmed in the video on the previous step. Arrows, animation, and text characters are all possible.

Can I change the patterns?
Yes.  You'll need an SX Blitz programming key, but otherwise it's pretty straightforward. The last step of this instructable has as link to the source code that you can modify.

The Spinning LED display was designed by microcontroled1204.

Step 2: Preperation: Parts List

Parts list

If you've bought the kit from Gadget Gangster, check to make sure all the parts are included. If anything is missing, just shoot us an email at info@gadgetgangster.com.

28 pin DIP socket (mouser part # 571-1-390261-9)

small DC Motor (Solarbotics is one source)

An SX 28 DIP (If you buy the kit, the SX will come pre-programmed). You can get this from Parallax

8x 3mm Red LED's

Spinning LED Display PCB (Source: Gadget Gangster)

1 or 2 CR2032 or CR2016 Button Cells

Button Cell holder (mouser part#  122-2420-G)

8x 120 ohm Resistors (Brown - Red - Brown)

1x 10k ohm Resistor (Brown - Black - Orange)

2xAA battery pack (mouser part #

Step 3: Preperation: Tools

This is a great project to learn how to solder. There are a ton of great instructables on how to solder (one here)

You'll need a few tools to assemble the project;

1 - Soldering Iron and solder. Leaded solder is easier to work with, and a 15-40 watt iron is just fine. A conical or chisel tip works well.

2 - Dykes. Diagonal cutters are used to trim the excess leads from components after soldering them down. 

3 - Batteries. You'll need 2xAA batteries.

If this is your first electronics project, I suggest you start with an inexpensive soldering iron. Why? Because you'll be able to get a feel for doing electronics projects without spending a lot of money. If you enjoy yourself, then you can upgrade to better equipment and give your 1st iron to someone else who is just starting out. I offer an Elenco kit that includes a 25 Watt iron, stand, wick, and a solder sucker for $25 (pictured below). You can also get a pretty nice Weller iron on Amazon that includes extra tips and solder (but no wick or solder sucker) for $15.

Step 4: Make Part 1

The 8 identical Resistors (Brown - Red - Brown, 120 ohms) go at R2 - R9. Let's start by adding 2 of them to R8 and R9. Fold the leads at a 90 degree angle, insert into the pcb, flip over, solder it down, and trim off the excess leads.

Step 5: Make: Part 2

Then we'll do the second set of resistors. Again, 120 ohms (brown - red - brown), at R5, R6, and R7. Insert, flip, solder, and trim.

Once the first two rows are in, we'll do the same thing for the last row (R2, R3, and R4). Same resistors, 120 ohm (brown - red - brown).

Step 6: Make: Part 3

The 10k ohm resistor goes at R1. It's brown - black - orange and goes as shown on the photo.

Step 7: Make: Part 4

Let's add the LED's. Note that the LED's are polarized. The longer lead goes in the square hole (to the right). Insert it part of the way and fold it, so the LED goes past the edge of the PCB. Solder it down and trim the excess leads.

Do the same thing for the other 7 LED's. Make sure the polarity is correct - the longer lead always goes through the square hole.

Step 8: Make: Part 5

With the LED's done, let's move on to the DIP socket. Note that the notch of the socket goes closer to the 10k ohm resistor (points left in the photo).

Step 9: Make: Part 6

Flip the board over and add the button cell holder. This device is also polarized, notice how it's inserted in the photo, the 'tower' side of the holder goes through the hole closer to the LED's.

This holder will hold one or two CR2016 cells, or a single CR2032 cell. The SX isn't picky and it will run on any configuration.

Step 10: Make: Part 7

Back to the top side of the PCB, trim off the excess leads from the button cell holder and drop the SX into the DIP socket. We're almost done - the last step is to attach the motor.

Step 11: Make: Part 8

In the photo below, you can see how I've attached the motor. I used a bit of excess leads (from the resistor) to make a loop, and put the Motor spindle through the loop. Once that was done, I used a healthy dollup of solder to solder the spindle to the PCB and to the loop.

It's your choice as to where to connect the motor. If you connect it in the center, like in the photo, it will spin fairly quickly. I suggest connecting it to the edge of the PCB for a larger circle.

You also don't have to connect the motor at all - you can use the holes in the PCB to tie it to nearly any spinning device, like a bicyle wheel.

Last step - connect the AA battery pack to the motor at the 2 tabs on the motor. The battery pack has a red and black lead, but it doesn't matter which lead connect to which terminal.

Step 12: Download

I hope you enjoy the Spinning LED Display - Let me know what you think by commenting on this instructable or sending me an email at nick@gadgetgangster.com. 

Here's the sourcecode for the SX

Here's the PCB Layout
Diptrace format

Get the kit from Gadget Gangster

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    13 years ago on Introduction

     Normally when working with 'persistence of vision' devices you need a sensor of some kind hooked up to the micro controller so it can calculate your RPM's and adjust the timing of the leds accordingly.

    Seeing as i don't see any kind of sensor on this board, or a voltage mentioned that the motor has to be driven by, the 'persistence of vision' effect isn't going to work at all. 


    Reply 13 years ago on Introduction

    from the look of the video there is a definite drift of the stuff moving around the circle each frame of animation.


    Reply 13 years ago on Introduction

     Clean install of win7, so i didnt have flash installed, but now that ive seen it i know what i said was correct.
    Without the sensor for the timing calculations, there is no 'POV effect', just leds spinning.

    Gadget Gangster
    Gadget Gangster

    Reply 13 years ago on Introduction

    There's a bit of drift in the display, but it's timed with the particular motor (GM-3) and 3V.  It's hard to capture with a video, but there's definitely a persistence of vision effect. 


    Reply 13 years ago on Introduction

    As Berserk brings up though, its really easy with a processor that strong to even just use a spare led as a light sensor, a reed switch, a hall effect sensor, or an optical encoder to figure out the rotation speed accurately.

    Gadget Gangster
    Gadget Gangster

    Reply 13 years ago on Introduction

    I just made a quickie video that I think shows the effect better.  Again - it's hard to capture on video, but it gives you the idea;


    Reply 13 years ago on Introduction

    I don't doubt the pov effect - its a proven concept.  I'm on about the drift, where it randomly changes with slight fluctuations in motor speed - which can be easily fixed with a simple sensor...There are even ways to sense the motor position by measuring the pulses in the current used by the dc motor as the commutator switches coils.