davedarko05/14/2017 at 09:55 0 comments


    I've ordered some of CNLohr's RGBY LEDs for my WeMos shield, will update this once they arrive :)

  • HT16K33 board arrived

    davedarko05/11/2017 at 19:09 1 comment

    Board works :)

  • HT16K33 board for 11x7 LED matrix

    davedarko04/15/2017 at 16:04 5 comments

    I recently bought a cool 11x7 matrix, that is just great to display 4 3x5 digits and I want to control it with the well supported HT16K33 - so here's a not so beautiful and highly convoluted board for that.

  • 2nd try - this time with SK6812 LEDs

    davedarko03/03/2017 at 17:51 0 comments

    Definitely mooooaaar white :)

  • Got scammed on aliexpress? meh

    davedarko03/01/2017 at 11:40 7 comments

    So I thought I've bought the new SK6812 with RGBNW on aliexpress.com, but instead I received some standard RGB WS2812 LEDs - not cool :( but the shield works. Now I've bought half of the LEDs for the same price on eBay, let's see how that will turn out ;) dispute on aliexpress was opened, hoping for at least some refund.

    Order from OSH Park

  • 3 little boards - blinky stuff

    davedarko02/10/2017 at 19:37 2 comments

    Wemos 2812B moaaaar LEDs shield

    After seeing RGBW LEDs on the Adafruit stream I quickly went on Aliexpress to buy some and then designed a Wemos D1 shield for them, just not with only one LED.

    SMD LED bargraph for breadboards (with Resistors)

    A classic, but I was in the mood to design it.

    RGB LEDs charlie-plexed pinout

    This is basically the layout of one column of a 4x4x4 RGB LED cube...

  • HT16K33 to help with my ancient ancient displays

    davedarko10/13/2016 at 09:34 4 comments

    So at first I was about to edge a board and use some L2803s and 595s Shift registers, but then I saw that the HT16K33 matrix controllers are now so cheap that I bought 5 for 6,50 Euros. Lucky me, I've mistakenly marked the cathodes with red pins - but the math checks out. I have 3x5 positive pins and and 3x6 negative pins, so that makes 15 rows and 6 common columns - yay. https://cdn-shop.adafruit.com/datasheets/ht16K33v110.pdf 0x01 notes for the future - can anyone have too many displays?
    0x02 NTTF - Stargate LED matrices0x02 NTTF - Stargate LED matrices [UPDATE]

  • The flux compensator

    davedarko10/13/2016 at 04:35 5 comments

    Please. I know. It's flux capacitor. But that might happen to every german-syncronized-movie-watching person. Maybe it's because of the drawing that says "flux compression". I still want to know what happened there.

    Parts are all 1206 and super easy to solder.

    Version 1

    Version 1 - Rev 1

    Version 1 - Rev 2 - final

    I've updated the design to also have a battery holder and a switch (yay), also soldering points for a clip. Checkout #FLUX capacitor trinket for future updates :) ALSO: there's a four led, more resistors version by @Bastiaan - #Mini flux capacitor prop PCB

    Order from OSH Park

    int outer = 0;
    int center = 1;
    int inner = 2;
    int pwmValue = 22;
    int timeLength = 250;
    int delayValue = 10;
    void setup() {
      // put your setup code here, to run once:
      pinMode(outer, OUTPUT);
      pinMode(center, OUTPUT);
      pinMode(inner,  OUTPUT);
    void loop() {
      // put your main code here, to run repeatedly:
        softPWM (outer);
        softPWM (center);
        softPWM (inner);
    void softPWM (int pin)
      for (int j=0; j<timeLength/delayValue; j++)
        for (int i=0; i<pwmValue; i++)
          digitalWrite(pin, HIGH);
        for (int i=pwmValue; i<=255; i++)
          digitalWrite(pin, LOW);

  • props

    davedarko02/18/2016 at 09:41 5 comments

    Although this is meant to be a board in general, I also have this 3D file that I could totally scale to fit some EL wire or 3mm LEDs. It doesn't seem to be too accurate though.

    but initially this board was intended to be used on the blinking prop seen on 'Empire strikes back'. It's pretty easy to see the 555 with its caps, a 4017 to its right and the two ULN2004s with the 10 resistors for the 10 x 4 LEDs.

    The 4 stages:

     O # O
    # # # #
     # O #
     # # #
    # O # O
     # # # 
     # O # 
    # # # #
     O # O
     # # #
    O # O #
     # # #