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6. Electronics design

PCB_image

Overview of week 6 assignment

  1. Group assignment Use the test equipment in your lab to observe the operation of a microcontroller circuit board
  2. Individual assignment Use an EDA tool to design a development board that uses parts from the inventory to interact and communicate with an embedded microcontroller.
    Extra credit: try another design workflow
    Extra credit: design a case for it

1. Group assignment

For more information, see the Week 06: Group assignment page.

Don't put microcontrollers on Mac

To prevent the terminals from shorting out on your Mac's metal casing, don't place microcontrollers or other electronic components on top of your Mac!

2. Individual assignment

A. EDA tool

At FabLab Kannai, we learned through designing development board for RP2040, using Fusion Electronics because of the convenience of having good integration with CAD, CAM, etc.
Ref. Electronics overview

Fusion Electronics expands Fusion’s capabilities for electronic design, integrating a real-time schematic workspace with the PCB workspace. It supports SPICE-based simulation, Design Rule Checks (DRC), and exports designs via a CAM Processor for manufacturing compatibility.

Step 1: Fusion Electronics

  1. Create a folder before designing: Data Panel > New Folder
  2. File > New Electronics Design

  3. Essentially, 4 files will be created:

    • Electronics design: it integrate the following electronics design elements
      • Schematics: Conceptual diagram without actual parts placement
      • PCB layout: Physical layout of electronic components (2D)
      • 3D PCB design (Optional): 3D layout of electronic components for hardware engineering

    PCB (Printed Circuit Board) is a rigid board with conductive traces connecting electronic components, used in devices. It consists of a non-conductive base (e.g., fiberglass) with conductive traces. Components such as resistors and transistors are soldered onto the board to form a circuit.

    FusionElectronics

Step 2: Library

  1. Collect components from Library: Library > Open Library Manager library
    • Check what libraries are used by toggle the "In use"
  2. Download the library files (.flbr)
  3. Upload them to a specific Fusion folder

Step 3: Schematics

  1. Electronics Design > New Schematics
  2. Search and place components:
    • At the right panel > PLACE COMPONENTS > Filter (this case, XIAO)
    • Double click it > Place in the schematics (often it first appear behind the "ADD" panel) place
    • Place all the components
    • Design > Modify > Move and rotate

  3. Draw nets, names, labels:

    • Design > Connect > Net
    • Design > Connect > Name (Connect components by setting a same name)
    • Design > Connect > Label

    net_name_label

    Net is an electrical connections or paths that link components on PCB
    Name is a formal, unique identifier used for referencing elements in design files and systems (e.g., R1, R2, NET1)
    Label is a visual representation in the design, helping to make the schematic more readable (e.g., VCC, GND)

  4. Set values and organize

    • Modify > Value
    • Select components > Right click > New Group
    • Document > Draw > Line and Text (Lines and text for readability)

    value_group_line

    • PLACE COMPONENTS > Frame (if frames are not shown, check the Library Manager)

    schematics

Step 4: PCB

  1. Schematics > SWITCH > Switch to PCB document
    • Initially, all the components are not organized

  2. RULES > Design Rules > Custom

    • Copper Clearance > Minimum > 17 mil
    • Drill Size > Minimum > 0.8 mm (default unit is inch, but it automatically align units by adding "mm")
    • Copper Width > Minimum 16 mil

    mil: 1/1000 inch ≈ 0.0524 mm

    PCB_design_rules

  3. DESIGN > Route

    • ROUTE > Route Manual
    • QUICK ROUTE > Autorouter (didn't work well, not suitable for small PCB)
    • UNROUTE > Unroute and Unroute All to delete routes

  4. RULES > Check Design Rules

    • At the right panel > ERRORS > Errors > Air Wire
      (It wasn't connected properly. I should have routed to where the small cross mark appeared.)

    route_DRC

  5. DOCUMENT > DRAW > Dimension (to estimate overall size of the PCB)

Step 5: Push to 3D

  1. SWITCH > Push to 3D PCB

    3D_PCB

    3D components are missing due to the library issue.

Step 6: Design of enclosure

  1. File > New Design

    • On the Data Panel > Right click "PCB_3D" > Insert into current Design enclosure
    • New sketch for the PCB outline
    • Design enclosure based on the PCB dimensions

  2. Update the PCB outline matched to the enclosure

    • On the PCB_3D component > Edit In Place (Click the pencil icon)
    • PCB_3D > Sketches > Outline > Edit Sketch > Delete the sketch! (Warning appears)
    • Go to the history panel at the bottom > Edit Board
    • Select the new sketch from "Enclosure"

    update sketch

PCB_enclosure

3. Files

Afterthoughts

  • I need to learn basics of electronics.
  • PCB routing is kind of fun.