Complete STM32F4VE 4-Layer PCB Design — FOSSEE Autumn Internship 2026 Screening Task

[SanjayG-xls]

Summary

This pull request contains the complete PCB design and schematic files for an STM32F407VET6 microcontroller development board, developed as part of the screening task for the FOSSEE Autumn Internship 2026 program.
The design includes schematic capture, 4-layer PCB layout, design verification, 3D model generation, and manufacturing-ready Gerber output — all verified against JLCPCB base model manufacturing rules.

Changes Introduced

Schematic Design (eSim 2.5)

• Complete circuit schematic for the STM32F407VET6 development board
• Power management section with 3.3V routing and CR12 backup battery circuit
• Clock circuitry with HSE and LSE crystal oscillators
• USB 2.0 Full-Speed interface via Micro USB connector
• SD Card reader connected via SDIO interface
• Extensive GPIO breakout through 2.54mm pin headers
• User interface elements: tactile switches and status LEDs
• Wire labels used for power nets in place of standard power flags

PCB Layout (KiCad 6)

• 4-layer PCB stackup configured for JLCPCB base model fabrication:
  • Layer 1 (F.Cu): Signal routing with ground pour
  • Layer 2 (In1.Cu): Dedicated ground plane
  • Layer 3 (In2.Cu): Dedicated 3.3V power plane
  • Layer 4 (B.Cu): Ground plane
• Component placement optimized for signal integrity and thermal management
• Decoupling capacitors placed adjacent to all MCU power pins
• USB differential pair routing with matched trace lengths
• Short, guarded crystal oscillator traces

Component Libraries

• All schematic symbols, PCB footprints, and 3D STEP models sourced from SnapEDA
• Footprints cross-verified against manufacturer datasheets

Aesthetics and Manufacturing

• Black solder mask finish to replicate commercial STM32 development boards
• Custom silkscreen graphics on front and back layers (FOSSEE logo, STM logo, designer name)

Documentation and Images

• Comprehensive README.md with project details and image galleries
• Design document covering circuit description, routing methodology, and design considerations
• All screenshots and renders included in the Images/ directory

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Design Verification

Check	Result	Notes
Electrical Rules Check (ERC)	✅ Passed	Zero errors. Power nets use wire labels instead of power flags.
Design Rules Check (DRC)	✅ Passed	Zero errors. Fully compliant with JLCPCB 4-layer base model rules.
Clearance Violations	✅ None	All copper features meet minimum spacing requirements.
Minimum Trace Width	✅ Passed	All traces within manufacturer specifications.
Via Constraints	✅ Passed	Drill diameters and annular rings within JLCPCB tolerances.
Unconnected Nets	✅ None	All schematic connections realized in the PCB layout.
Courtyard Overlaps	✅ None	No component collision or placement violations.
3D Model Verification	✅ Passed	All components placed, oriented, and mechanically verified.

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Hardware Specifications

Parameter	Value
Microcontroller	STM32F407VET6 (ARM Cortex-M4, FPU, 168 MHz)
Flash / SRAM	512 KB / 192 KB + 4 KB backup
Operating Voltage	1.8V – 3.6V
Package	LQFP-100
PCB Layers	4
Target Manufacturer	JLCPCB (base model)
Solder Mask	Black
Interfaces	USB, SDIO, I2C ×3, SPI ×3, USART ×4, UART ×2, CAN ×2

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Tools Used

Tool	Version	Purpose
eSim	2.5	Schematic capture
KiCad	6 (via eSim)	PCB layout and 3D visualization
SnapEDA	—	Component libraries (symbols, footprints, 3D models)
GitHub	—	Version control and submission

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How to Review

1. Open the schematic files in eSim 2.5 to review circuit connections.
2. Open the PCB layout files in KiCad 6 to inspect routing, layer stackup, and 3D model.
3. Refer to the Images/ directory for all screenshots and renders.
4. Gerber files can be generated from the KiCad layout for fabrication verification.

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Checklist

• Schematic design completed in eSim 2.5
• PCB layout completed in eSim - KiCad 6 (4-layer stackup)
• All component libraries sourced from SnapEDA
• ERC passed with zero errors
• DRC passed with zero errors
• 3D model generated and verified
• Custom silkscreen applied (FOSSEE logo, STM logo, designer name)
• All screenshots and renders added to Images/ directory
• README.md with project documentation
• Design document with full technical details

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Author: Sanjay G — FOSSEE Autumn Internship 2026 Screening Task Submission