Small round board for 3D blinking



This small board is basically a breakout board for two DM634 LED driver chips with necessary capacitors and resistors soldered and a handy 5-pin UltiBlink in/out interface present. These boards were initially designed as rounded end-points for the UltiBlink RGB board (to connect the two lines of RGB LEDs on its sides), hence the cutting slot in the middle. While designing this board I liked the circular idea, so it ended up in a simple device for quick lighting projects. Just install 10 RGB LEDs around the BlinkeyBlinkey rim, connect it to your controller board and you’re ready to go!

BlinkeyBlinkeys are stackable on top of each other, making them a perfect choice for 3D-projects, be it a small round column with strings of LEDs around its rim or weird Christmas-tree-likes shown in photos. These boards are a good starting point for acquainting yourself with LED driving stuff: not only do you get to know the basics, you also instantly have something to show off!

And the best controller for these small thingies is the BlinkeyCore: same size, same shape, same holes layout! Just stack some BlinkeyBlinkeys on top of it.

Colors available: green, white.

Normal price: $9.45 + shipping

Sale price: $9.00 + FREE shipping!

Each additional BlinkeyBlinkey at $6.00!


LED controllers 2 x DM634
LEDs supported 10 x Common anode thru-hole RGB LEDs
Operating voltage 3.3 - 5.5 V
Installed REXT resistors 2 x 2.2 kΩ
Interfaces UltiBlink 5-pin
Dimensions 30 x 30 mm (±0.5 mm)

Default package contents:

1 x BlinkeyBlinkey board

1 x IN 1x5 male pin connector

1 x OUT 1x5 female pin connector



The Arduino DM63x library can be found here.

The board comes with a standard 5-pin UltiBlink interface (see manual), so programming it with any core board is pretty straightforward: just change the number of drivers accordingly while declaring the DMdriver object.

If used with an Arduino board, connect the IN interface as follows:

 5v -> 5v
 DAI -> Arduino digital pin 11 (MOSI)
 DCK -> Arduino digital pin 13 (SCK)
 LAT -> Arduino digital pin 9 (or any other free pin)
 GND -> common ground

Note that RGB LEDs tend to consume current, so it is a good idea not to connect the UltiBlink extensions directly to the 5v pin on the Arduino. If you use more than one extension, always use an external power supply!

With other microcontrollers, I suggest using SPI interface, but the drivers can also be bit-banged. Check the DM634 datasheet.


Small round Arduino for LEDs or other compact projects



The Core is a small barebone prototyping board based on Atmega328 microcontroller (Arduino-compatible). The unused pins are broken out around its rim, and in the center is its main UltiBlink/SPI interface connector. This board can be programmed by ISP (including an Arduino running ArduinoISP sketch) or UART (bootloader present) programmers.

Initially designed as a base controller for BlinkeyBlinkeys, the Core is in fact pretty universal board. Nowadays I have half a dozen of them lying around for use in prototypes because of their handy 5-pin UltiBlink/SPI  interface and the presence of a microUSB power connector. These boards can be useful even in projects with no relation to the UltiBlink peripherals: you can connect anything SPI-controlled to the central 5 pins.

There’s a place for the RTC chip and battery connectors on the back. These can be soldered by yourself or ordered as an option.

Available colors: white, green, black(*).

(*) black version has a low-pass filter on AVCC.

Normal price: $10.45 + shipping

Sale price: $9.90 + FREE shipping!

BlinkeyPack (1 Core + 3 BlinkeyBlinkeys): $26.90!


Microcontroller Atmel ATmega328p @ 16MHz
Operating voltage 5 V
Programming voltage 5 V
Available digital I/O pins 8 (marked, on the rim) + 5 (interface)
Available analog pins 8 (A6 & A7 analog only)
Programming interfaces ISP
UART (bootloader pre-installed)
Data interfaces I2C (10K pullup resistors can be installed)
SPI (shared with LED drivers)
Dimensions 30 x 30 mm (±0.5 mm)

Default package contents:

1 x BlinkeyCore board

1 x ISP 2x3 male pin connector

1 x UART 1x5 male pin connector (angled)

1 x OUT 1x5 female pin connector



The board is supplied as a kit byt default. The kit includes the board itself with soldered SMD components and a set of pin headers to be soldered by yourself.
There are additional options you can select at extra cost:

Fully soldered board add $1.00
Female ISP header (useful if programmed using Arduino) add $0.50
10K pullup resistors for I2C interface $0.00
DS3231 RTC chip + battery holder(*)

add $1.50

The options can be combined in any way possible, please contact me with your express wishes.

(*)CR2032 battery not included due to post-office rules. Please provide your own.


The BlinkeyCore can not be connected to the computer directly; like the Arduino Pro Mini it requires a programmer. Any generic Arduino board can act as such thanks to the Arduino ISP sketch.

There are two programming interfaces present:

- ISP (In-System Programming). The easiest way to program the BlinkeyCore, as you’ll just need to connect it to your Arduino following the instructions in the ArduinoISP sketch present among the pre-installed examples in the Arduino IDE. A dedicated ISP programmer can also be used, such as a USBtinyISP one.

- UART (serial). UART pinout includes the DTR line that controls an automatic reset function. You’ll need a programmer for this interface: either the dreaded FTDI or a more safe, affordable and recommended CP2102 one. Bootloader is preinstalled (please note that it is erased when the ISP interface is used).

Any software capable of programming Atmel chips can be used, but I recommend the Arduino IDE to program the board, as it is easy to use and understand. In the IDE, select ‘Arduino Pro or Pro Mini’ in the Tools > Board menu, then ‘ATmega328 (5V, 16MHZ)’ in the Tools > Processor menu. If using ISP (either Arduino or a dedicated programmer) make sure to select the correct option in the Tools > Programmer menu and upload your sketches with Sketch > Upload Using Programmer option (or just Shift-click on the Upload button).

The DM63x library can be found here: