Fibonacci256 Pixelblaze

Posted August 19, 2022


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Table of Contents

Details

Fibonacci256 is a beautiful 166mm circular disc with 256 RGB LEDs surface mounted in a Fibonacci distribution. Swirling and pulsing like a colorful galaxy, it’s mesmerizing to watch.

It consists of 256 WS2812B-Mini 3535 RGB LEDs, arranged into a circular Fermat’s spiral pattern.

I have created several LED art pieces in Fibonacci patterns. They are all very labor intensive to create, and so are fairly expensive and limited in quantity. I wanted to come up with a Fibonacci layout that was at least slightly easier to create, and therefore more affordable.

I have RGB LEDs in just about every form they come: strips, strings, rings, discs, etc. The LEDs on most discs are arranged in very regular rings. Fibonacci256 is different. The LEDs are arranged in a Fibonacci distribution. The makes the layout very organic and seemingly messy. But with the proper animation, spiral patterns emerge with spectacular results.

Each of the 256 WS2812B-Mini 3535 RGB LEDs has its own decoupling capacitor built in. The top and bottom of the PCB are large 5V and GND planes, to allow for the large amount of current required by the 256 LEDs. The max theoretical frame rate is ~130 FPS.

In disc phyllotaxis, as in the sunflower and daisy, the mesh of spirals occurs in Fibonacci numbers because divergence (angle of succession in a single spiral arrangement) approaches the golden ratio. The shape of the spirals depends on the growth of the elements generated sequentially. In mature-disc phyllotaxis, when all the elements are the same size, the shape of the spirals is that of Fermat spirals—ideally. That is because Fermat's spiral traverses equal annuli in equal turns. The full model proposed by H Vogel in 1979[2] is

r = c \sqrt{n},
\theta = n \times 137.508^\circ,

where θ is the angle, r is the radius or distance from the center, and n is the index number of the floret and c is a constant scaling factor. The angle 137.508° is the golden angle which is approximated by ratios of Fibonacci numbers.[3]

Fermat's spiral. (2015, October 24). In Wikipedia, The Free Encyclopedia. Retrieved 02:45, February 24, 2016, from https://en.wikipedia.org/w/index.php?title=Fermat%27s_spiral

Connecting

Your Fibonacci256 should automatically play a playlist of pre-selected patterns endlessly.

For more control, you can connect to it via wi-fi.

To connect your Fibonacci256 to a wi-fi network:

  1. If not already connected to a wi-fi network, your Fibonacci256 will create its own network named Pixelblaze_XXXXXXX, where XXXXX is a code unique to your Fibonacci256. You should see it in the list of wi-fi networks available on a computer or mobile device:

    Note: If you can’t find the Fibonacci256’s wi-fi network, it may not be in setup mode.

    To put it in to setup mode:

    1. Press and hold the button for 5 seconds.
    2. If the status LED on the back flashes 5 times, it’s now in setup mode.
    3. If the status LED on the back flashes once, press and hold the button for 5 more seconds. The status LED on the back should now flash 5 times,
    4. It should now be in setup mode and its wi-fi network should now appear in the list on your computer or mobile device.
  2. Connect to this network from a computer or mobile device.

  3. You should see a pop-up and/or automatically get redirected to configure the Fibonacci256’s wi-fi settings. If not, open a browser and go to http://192.168.4.1

In WiFi Settings you an configure your Fibonacci256 to run in one of two modes:

Client Mode - Connect to a network

In this mode your Fibonacci256 can connect to an existing wi-fi network. Use this mode while at home or another location with an existing wi-fi network that you can connect to.

  1. Choose the wi-fi network to which you’d like to connect, or enter the SSID (Name) if you know it, it’s hidden, etc.

  2. Enter the password for the wi-fi network.
  3. Leave Enable Discovery Service enabled to use the Pixelblaze Discovery Service, which makes it much easier to find your Pixelblaze on your wi-fi network later.

  4. Click Submit to connect.

  5. Once it has connected, it will have an IP address on your wi-fi network.
  6. The computer or mobile device you’re using should automatically re-connect to its previous network (your home wi-fi, mobile data, etc).
  7. If you left it enabled, use the Pixelblaze Discovery Service to find your Fibonacci256.
  8. If you’re unable to find your Fibonacci256’s IP address, you can use these instructions for finding a Raspberry Pi.
AP Mode - Create a stand-alone network

In this mode your Fibonacci256 will create its own wi-fi network that you can connect to from another device. Use this mode when outdoors or away from other wi-fi networks.

If you’ve already chosen Client Mode and followed the instructions above, skip down to Next Steps

  1. Enter an SSID (Name). This is the name of the wi-fi network that you will connect to from other devices to configure your Fibonacci256.
  2. Enter a password at least 8 characters long. Passwords with fewer than 8 characters will not work.
  3. Now you should be able to use a computer or mobile device to connect to the wi-fi network with the SSID (name) you entered in step one above.
  4. Once connected, open a browser and enter the address http://192.168.4.1

Congratulations! You should now be able to connect to and configure your Fibonacci256!

Settings

After you’ve gotten your Fibonacci256 connected to a wi-fi network, there are a few settings you should check and be aware of.

Open your Fibonacci256’s web app and click on the Settings tab.

We won’t go over every setting on this page, just the ones that are important for the use of your Fibonacci256.

  • Name: you can give your Fibonacci256 a unique name to differentiate it from others. This is especially useful if you have multiple Fibonacci256s and/or Pixelblaze controllers on the same network.
  • LED Settings:
  • Limit Brightness: Warning! we recommend you keep this at or below 50%! It is possible for high brightnesses and patterns that use a lot of white or desaturated colors to draw a lot of power, potentially causing high temperatures and reducing the LED life time.

These settings should always be set to the following values to match the type and quantity of LEDs in your Fibonacci256:

  • LED Type: WS2812 / SK6812 / NeoPixel
  • Pixels: 256
  • Data Speed: 800 Kbps 270ns/630ns
  • Color Order: GRB
  • CPU Speed: 240 MHz (Fastest)

Mapper

You shouldn’t need to change anything on the Mapper tab. This page just contains the pixel map, which is the location of each of your Fibonacci256’s LEDs. It’s used by the Pixelblaze controller in patterns.

If you ever do need to reset to the Fibonacci256’s default map, use these values:

[[122,126],[99,120],[90,109],[87,96],[90,82],[97,69],[108,57],[123,49],[141,45],[160,45],[179,50],[198,59],[214,74],[227,92],[236,114],[240,138],[238,163],[231,188],[218,211],[199,231],[132,255],[159,248],[182,235],[202,218],[217,198],[227,175],[231,152],[230,129],[224,107],[214,89],[200,74],[184,63],[166,57],[149,56],[133,59],[119,66],[109,76],[103,88],[103,102],[112,116],[117,103],[119,88],[127,77],[140,71],[154,68],[170,70],[185,77],[199,88],[211,103],[218,121],[222,141],[221,163],[214,184],[202,205],[186,222],[165,236],[141,245],[115,249],[88,247],[29,208],[51,224],[75,235],[101,241],[126,240],[149,234],[170,223],[188,209],[201,191],[209,172],[212,152],[211,132],[205,115],[195,101],[183,90],[169,84],[155,82],[142,86],[132,95],[127,114],[138,107],[151,98],[165,98],[177,103],[188,112],[196,126],[201,142],[201,159],[196,177],[187,195],[173,210],[155,222],[134,230],[112,233],[88,230],[64,223],[43,209],[24,191],[9,168],[0,142],[4,98],[4,125],[10,151],[22,174],[37,194],[56,209],[77,219],[99,223],[121,223],[141,218],[159,208],[173,195],[182,180],[188,164],[189,148],[185,134],[177,122],[166,114],[152,112],[144,123],[161,128],[171,138],[175,151],[174,165],[169,180],[159,193],[146,203],[129,211],[110,214],[90,212],[70,206],[51,194],[35,178],[22,158],[14,134],[11,109],[14,83],[23,58],[38,35],[76,11],[54,28],[38,48],[26,71],[20,95],[20,120],[25,142],[35,163],[48,179],[65,192],[83,200],[101,203],[119,202],[134,196],[147,187],[156,175],[160,162],[159,148],[151,136],[135,133],[145,152],[144,166],[137,177],[125,186],[111,190],[95,191],[79,187],[63,178],[49,165],[38,148],[31,128],[28,107],[31,84],[39,62],[53,41],[71,24],[93,11],[118,2],[145,0],[211,28],[187,16],[161,9],[135,8],[110,13],[87,23],[68,37],[53,55],[43,75],[39,96],[39,116],[43,135],[52,151],[64,164],[78,173],[93,177],[107,177],[120,172],[129,162],[133,146],[119,153],[108,161],[94,163],[81,160],[69,152],[58,139],[51,124],[49,106],[50,87],[57,69],[68,51],[83,36],[103,25],[125,18],[149,16],[174,20],[197,29],[219,44],[238,64],[255,133],[250,106],[240,81],[225,60],[206,44],[184,32],[162,26],[139,25],[117,29],[98,38],[82,50],[70,65],[63,82],[60,99],[62,115],[68,129],[77,140],[89,147],[103,148],[118,138],[106,134],[91,131],[80,122],[75,110],[73,95],[76,80],[84,65],[96,52],[112,42],[130,36],[150,34],[172,37],[192,45],[211,59],[227,77],[239,98],[246,123],[248,149],[243,176],[232,202]]

Patterns

Fibonacci256 comes with a wide variety of patterns built-in. By default, it will automatically play a playlist of pre-selected patterns.

  • Color Waves
  • Pride
  • Stars
  • Palette Noise
  • Palettes Outward

The sequencer can be configured via the web interface over wi-fi in the following ways:

Pattern sequencer options:
  • Off: Continuously play your selected favorite pattern. You can manually move to the next pattern by clicking the button on the back.
  • Shuffle All: randomly shuffle between all patterns after playing each one for an adjustable duration.
  • Playlist: patterns can be arranged into a playlist with customizable order and duration for each pattern.

Specifications

  • Size: 6.54 x 6.54 x .063 inch (166 x 166 x 1.6 mm)
  • 2 layer printed circuit board
  • FR4 substrate
  • Black SMOBC (solder mask over bare copper)
  • HASL (Hot Air Solder Leveling)
  • Designed and assembled in the US by Evil Genius Labs

Retrofit Kit

Parts:

Instructions:

  1. Unplug any connected USB or power cables.
  2. Remove the screws from the back, and set them aside. We’ll need them later to secure the new acrylic back on.
    • Depending on which model you have these may be M3 or M2 screws.
  3. Remove the back cover. This will be replaced with the new back panel.
  4. Unplug the cable from the controller and/or the Fibonacci256 LED PCB.
    • These can differ from the pictures between Fibonacci256 models.
  5. If the controller is mounted using double-sided foam tape, use a generous amount of isopropyl alcohol to loosen the adhesive. Fully saturate it.
  6. Do not use anything metal to pry the controller off. If needed, you can use a plastic scraper, putty knife, or credit card.
  7. Use alcohol and a plastic scraper to remove any foam tape or adhesive residue.

Pixelblaze output:

  1. Place the 4 pin JST-XH connector into the holes on the left side of the Pixelblaze (GND, DAT, CLK, and 5V).
  2. Flip it over and solder all four pins.

Pixelblaze expansion pins:

  1. Place the 7 pin header that came with the Pixelblaze Sensor Expansion in the holes in the bottom right corner of the Pixelblaze, not the expansion board. Note that the GND, RST, 3v3, RX, TX, IO0, and IO25 should have pins, and that IO26 will not have a pin.
  2. Ensure the 7 pin header is inserted all the way down, and that there are pins in the GND, 3v3, and RX holes on the Pixelblaze.
  3. Flip the Pixelblaze over and solder at least the GND, 3v3, and RX pins.

Pixelblaze Sensor Expansion Board:

  1. With the Pixelblaze right-side up, with the pins pointing upwards, flip the Sensor Expansion Board over so the audio input jack is on the bottom, pointing down.
  2. Place the sensor board onto the Pixelblaze pins.
  3. Ensure that the GND, 3v3, and RX pins on the Pixelblaze are lined up and inserted into the GND, 3v3, and TX pins on the Sensor Expansion board. Note that the TX pin on the Sensor Expansion board is connected to the RX pin on the Pixelblaze
  4. The top of the audio input jack should be flush with, and not extend beyond the bottom of the Pixelblaze PCB.
  5. Double-check the pins are aligned and match up one more time.
  6. Solder at least the GND, 3v3, and TX pins on the Sensor Expansion board.

Acrylic back and standoffs:

  1. All screws should be inserted from the matte side of the acrylic, with the standoffs on the glossy side. Loosely mount the standoffs with the screws until everything is mounted, then hand tighten.
  2. Place the acrylic back with the glossy reflective side of the acrylic back facing up and the connector opening on the bottom.
  3. Loosely secure two of the M2x7mm standoffs onto the two right-most holes, near the Micro USB label, with two M2x5mm screws. Insert the screws from the matte side. The heads of the screws should be on the matte side, the standoffs should be on the glossy side.
  4. Hand tighten one M2x10mm standoff in the next hole to the right (the one with the Audio In label) with a M2x8mm screw.
  5. Loosely secure one M2x7mm standoff onto the hole nearest the 5V DC label using one M2x5mm screw.
  6. Hand tighten the last M2x10mm standoff in the hole above the 5V DC label using one M2x8mm screw.

Mount the Pixelblaze and Sensor Expansion assembly

  1. Place the Pixelblaze onto the two short standoffs on the glossy side, lining up the two mounting holes.
  2. Hand tighten and secure in place with two M2x5mm screws. The bottom edge of the Pixelblaze with the USB connector and the bottom edge of the Sensor Expansion board with the audio input jack should line up with the edge of the access panel opening in the acrylic.

DC input board:

  1. Place the DC input board with the jack facing downward onto the remaining short standoff near the 5V DC label, lining up the mounting hole.
  2. Hand tighten and secure in place with one M2x5mm screw.

Ensure all screws are hand tightened, including the ones on the matte side of the acrylic back.

Cables:

  1. One of the new cables included with the kit has three pins on one side and four on the other. Insert the end with four pins into the connector on the Pixelblaze (GND, DAT, CLK, 5V). Ensure the red wire is connected to 5V, the middle wire is connected to DAT, and the remaining wire is connected to GND.
  2. Insert the other cable into the connector on the 5V DC board. The red wire should be connected to 5V.
  3. Place the Fibonacci256 face down next to the back panel.
  4. Connect the Pixelblaze cable to the Data In connector on the Fibonacci256. Ensure the red wire is connected to 5V.
  5. The 5V DC cable may be longer than needed. If so, coil up any excess.
  6. Flip the back panel over, on top of the Fibonacci256, and connect the remaining cable.
  7. Ensure the red wire is connected to 5V.

Secure the new back panel in place using the screws you set aside earlier, after removing the old back cover.