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Building Blocks

Form is Function

Debra Ansell/GeekMomProjects

Hackaday Remoticon 2021

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Debra Ansell

GeekMomProjects

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“LEDs improve everything”

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Modular Assemblies

Mixed Component PCBs

Hack/Mod/Wear

Cat Lamp Soldering Kit

Creator:

Elkai Education

Image Source:

Adafruit

Creators:

Mary Etta West

Angela Sheehan

Image Source:

Hackaday.io

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Modular Assemblies

Uniform Component PCBs

Aluminum PCB Lamp

PCB Icosahedron

Creator/Source:

Daniel Hienzsch/

Rheingold Heavy

Creator/Source:

@brainsmoke (Twitter)

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Self-Connecting PCB Building Blocks

Inspiration: Wall Mounted Light Tiles

  • Identical elements
  • Simple circuitry
  • Self-connecting
  • Reconfigurable
  • Scalable build size
  • LEDs (!)

My Modular PCB Design Traits

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Low-Stress PCB Projects

Or: How I Stopped Worrying and Learned to Love the BOM

Follow tutorials carefully.

Send meticulous designs to fab.

Get PCBs. Find inevitable mistakes.

Stop worrying. Start experimenting!

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LEDs on PCBs

Spread the Light

“Inner Glow” Illumination

LEDs

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Simple Circuits

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TBD: May omit this slide for lack of time/interest

Triangle Light Tile Schematic

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Making Light Tiles

PCB Fabrication

PCB Assembly

SK6812 4020 LEDs

Laser Cut Acrylic

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Is It Cost Effective

To Use PCBs as Construction Material?

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QTY: 50 (95mm x 84mm, Lead Free)

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$41.80/(50 tiles) = $0.84/tile

PCBs (JLCPCB)

Translucent Acrylic (JPPlus Plastics)

1 Sheet (12” x 24”)

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($17.81/sheet)/(33 tiles/sheet) = $0.54/tile

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Searching for Connections

  1. Mechanically stable
  2. Electrically reliable
  3. Aesthetic
    1. Low Profile
    2. Surface Mount
  4. Affordable
  5. Obtainable

Ideal Connector

Candidate Search

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  • Surprisingly hard to find exact match
  • Good filter essential for online search
  • Compromise is required

Searching for connectors is like dating:

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Connector Contenders

Ultimately none were strong enough

RUNNERUP

Too Tall

Too Expensive

Too Bulky

Too Few Mating Cycles

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DIY PCB Connector

Pressure Contact

Acrylic

Buffer

Mates with Solder Pad

Pressure contacts need fewer parts, use smaller footprint than header pins

Pressure Contacts vs. Header Pins

Contacts

Covered

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Connections are Hard

Signal

Shim

Reinforcing

Connector

Reinforcements

Issue: Torque ∥ tile plane ⇨ sag

Fix: Reinforcements & tighter tolerances

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Issue: Torque ⟂ tile plane ⇨ separation

Fix: Contact points closer to screws

Mechanical

Issue: Voltage drop in larger assemblies�

Fix: Symmetric connector pinouts so connectors can transmit power to all adjacent tile sides (e.g. V|G|S|G|V)

Electrical

Sag

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Tiny Tiles

Scaled-Down Wearable PCB Tiles

Not enough space for

connector on tile

Recycled tiles in

wired cuff bracelet

0.05” pitch PTH header

difficult to solder

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Another Dimension

Light Tile Octahedron

3D Printed

Brackets

Gemma M0

+ LiPo

Magnetic Closure

Soldered

Connections

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Unusual Flexibility

Hinged PCB Links

Dollhouse Hinges (!)

Acrylic

Bezel

Hot Glue

Wire Reinforcements

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PCB Links 2.0 (Unhinged)

Rotating Connectors

(credit: @r1ckp)

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Pivot in a New Direction

Rotating Links, “Bendy Boards”

Mechanical Design

Ring Pads + Pressure

Connector

Inside Each Link

Mezzanine

Connector

Joins Links

Electrical Design

Push Rivet

As Pivot Axis

Acrylic Buffer

Single Link

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NEW DESIGN

DEBUT!

This slide intentionally left blank until presentation time

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Takeaways

  • Modular tile systems perform many functions, and look cool doing it
  • PCBs make a viable, affordable construction material
  • There is no perfect connector, and making your own is an option
  • Dollhouse hinges are fun and look nice, but aren’t safe
  • Experiment, experiment, experiment!!!