This video provides a comprehensive, step-by-step tutorial on designing a custom Printed Circuit Board (PCB) for a CH32V006 microcontroller using KiCad 9. The process begins with schematic creation, including designing a custom symbol and footprint for the microcontroller, and laying out essential circuits for USB-C power delivery, 3.3V voltage regulation, a 24 MHz crystal oscillator, a UART-to-USB converter, and GPIO headers. The tutorial then transitions to the PCB layout phase, demonstrating component placement, setting board dimensions for breadboard compatibility, routing strategies for a dense QFN package, managing power and ground planes, and adding silkscreen labels. Finally, the video guides the user through generating Gerber and other production files and placing an order with the manufacturer, PCBWay, detailing the various options for board fabrication and assembly.
Designing a CH32V006 Development Board from Scratch in KiCad 9
0:52 Creating Custom Symbols: The tutorial starts in KiCad's symbol editor, showing how to create a new library and a custom schematic symbol for the CH32V006 microcontroller, as it's not in the standard libraries.
8:01 Assigning Footprints: The creator demonstrates how to find the correct QFN-32 footprint in the KiCad library based on the microcontroller's datasheet and assign it to the custom symbol.
21:27 Voltage Regulation: A low-dropout (LDO) voltage regulator (LP5907) is added to convert the 5V from USB to the 3.3V required by the microcontroller.
26:46 Importing 3rd-Party Components: A practical guide on how to download and import a 3rd-party ECAD model (symbol, footprint, and 3D model) for a specific switch from a supplier like Mouser.
34:22 Oscillator Circuit: An external 24 MHz crystal oscillator is added to the design, with careful selection of 4pF load capacitors, noting that these smaller capacitors use a 0402 footprint.
40:41 UART-to-USB Bridge: A CH340N chip is integrated to provide a convenient UART-to-USB interface for communication and programming, with its circuit designed for 3.3V operation.
52:38 Starting the PCB Layout: The components are imported into the PCB editor. The board's dimensions are carefully set to be narrow enough to fit on a standard breadboard, and the board outline is drawn with rounded corners for a better finish.
1:00:23 Setting Design Rules for Dense Packages: A key tip is shared: the trace clearance in the design rules must be lowered to 0.15mm to successfully route traces out from the tightly spaced pins of the QFN-32 package.
1:01:35 Component Placement: The video shows a logical component placement strategy, placing the USB connector at the edge, the microcontroller in the center, and related components grouped together.
1:18:21 Routing Differential Pairs: The D+ and D- USB lines are routed as a differential pair to maintain signal integrity.
1:30:16 Routing GPIOs and Managing Layers: The creator demonstrates how to route the numerous GPIO pins to the headers, using both the top and bottom copper layers with vias to navigate the crowded layout.
1:48:21 Using Plugins for Aesthetics: A KiCad plugin ("Round Tracks") is used to automatically convert all the sharp-angled traces into smooth, curved ones for a more professional look.
1:49:00 Final Checks and DRC: A final Design Rule Check (DRC) is performed. The creator explains how to interpret and resolve or safely ignore certain warnings, such as unrouted USB shield connections which are physically connected by the component itself.
1:50:12 Generating Production Files: The tutorial concludes by showing how to generate all the necessary manufacturing files, including Gerbers, drill files, and the pick-and-place file.
1:51:28 Ordering from a Manufacturer: The user is guided through the process of uploading the Gerber files to PCBWay's website and configuring the order, explaining options like board color, thickness, stencils for manual assembly, and the turn-key assembly service.