Microcontroller and PCB project
DIY Arduino-Compatible Development Board
A custom Arduino-style board designed from schematic to firmware bring-up, focused on understanding MCU hardware, power design, USB programming, and reliable prototyping workflows.
Overview
This project started as a way to move beyond using prebuilt Arduino boards and design one from first principles. The goal was to build a compact, reusable board that remains Arduino-compatible while exposing the full hardware stack: clocking, reset behavior, decoupling, USB serial, and bootloading.
Design goals
- Stay compatible with Arduino toolchains and common workflows
- Expose clean GPIO, UART, SPI, and I2C access for prototyping
- Build robust power and reset circuitry for repeatable behavior
- Keep the layout compact while preserving debugging access
Hardware architecture
MCU core
An Arduino-compatible AVR microcontroller with external clocking and decoupling forms the main processing core.
Power and regulation
Input protection and voltage regulation provide a stable rail for the MCU and connected peripherals.
Programming and serial
USB-to-UART support and bootloader access simplify flashing firmware and reading runtime debug output.
I/O breakout
Header mapping is arranged for practical prototyping with digital, analog, and bus interfaces available at the board edge.
Development process
Schematic and pin planning
Defined MCU pin usage, reset behavior, oscillator design, and communication interfaces before layout.
PCB layout
Routed with attention to short return paths, local decoupling, and practical connector placement for breadboard and bench use.
Bring-up and validation
Verified power rails, upload path, and core firmware operation with iterative test sketches and serial diagnostics.
Iteration
Refined footprints, silkscreen labels, and routing based on assembly and test feedback from early board revisions.
Project gallery
Add your images to public/projects/arduino and keep the filenames below. Each slot is prepared so you can drop in visuals as the build evolves.
Board render
Top-side PCB render showing component placement and connector layout.
/projects/arduino/board-render-top.jpg
Schematic overview
Block-level schematic screenshot of power, MCU core, and programming path.
/projects/arduino/schematic-overview.jpg
Assembled board
Photo of the assembled board during bench testing.
/projects/arduino/assembled-board.jpg
Bring-up test setup
Bench setup with USB serial and test firmware running.
/projects/arduino/bringup-test.jpg
What this project develops
- +Microcontroller hardware design and pin planning
- +Power integrity and practical board-level electronics
- +Embedded firmware bring-up and debugging
- +Iterative PCB design for manufacturability