Rp2040

RP2040-Based Embedded Controller

Overview

Controller V1 is a custom handheld game-controller board built around the Raspberry Pi RP2040 microcontroller. It was designed from scratch in KiCad, covering schematic capture, power design, and full PCB layout.

The board is powered over USB-C, regulates 5 V down to 3.3 V with a synchronous buck converter, and carries an 8-button input matrix (D-pad + A/B + Mode/Select) plus a dedicated reboot button, an external QSPI flash chip for program storage, an I²C header for a monochrome OLED, an SWD debug port, and a 4-channel ADC breakout — making it a solid base for handheld gaming and general embedded projects.

Features

• Raspberry Pi RP2040 microcontroller
• USB Type-C power input
• TLV62569 synchronous buck converter (5 V → 3.3 V)
• External Winbond W25Q128JVSIQ QSPI flash memory
• 12 MHz crystal oscillator (ABM8-272-T3)
• 8-button input matrix: UP / DOWN / LEFT / RIGHT / A / B / MODE / SELECT
• Dedicated hardware REBOOT button
• Status LED (with current-limiting resistor)
• I²C header for monochrome OLED display
• 4-channel ADC breakout header (ADC0–ADC3)
• Full GPIO breakout header
• SWD programming/debug connector (SWCLK / SWDIO)
• Custom 2-layer PCB

Hardware Specifications

Hardware Architecture

USB-C (5V)
   │
   ▼
TLV62569 Buck Converter (3.3V)
   │
   ▼
RP2040 MCU
   │
   ├── External QSPI Flash (W25Q128JVSIQ)
   ├── 12 MHz Crystal Oscillator
   ├── SWD Debug Header (SWCLK / SWDIO)
   ├── OLED Display Header (I²C: SDA / SCK)
   ├── 8x GPIO Buttons (UP/DOWN/LEFT/RIGHT/A/B/MODE/SELECT)
   ├── Reboot Button
   ├── 4-Channel ADC Header (ADC0-ADC3)
   ├── Full GPIO Breakout Header
   └── Status LED

Schematic

Power Supply

The power stage accepts 5 V from a USB-C receptacle and steps it down to 3.3 V using a TLV62569ADRLR buck converter, with input/output filter capacitors and feedback resistors sized for the 3.3 V rail. This sheet also contains the reboot switch, status LED, the OLED I²C header, the ADC breakout, the full GPIO pin header, and the full button matrix (D-pad, A/B, Mode/Select).

RP2040 Core

The MCU sheet includes:

• RP2040 with USB D+/D- routed to the USB-C connector
• 12 MHz crystal oscillator with load capacitors
• External QSPI flash (W25Q128JVSIQ) wired to the RP2040's QSPI bus
• SWCLK / SWDIO debug breakout
• Full set of decoupling capacitors on IOVDD / ADC_AVDD / VREG_VIN / DVDD

PCB Layout

Layout / Routing View

3D Top View

Bottom / ADC & Debug Header View

Design Highlights

• Designed entirely in KiCad (schematic + PCB)
• Custom schematic capture and net labeling for clarity
• Complete 2-layer PCB layout from scratch
• Proper RP2040 support circuitry (crystal, decoupling, QSPI flash)
• USB-C powered with a switching regulator for efficiency
• Expandable GPIO, ADC, and I²C headers for add-on peripherals
• SWD debugging interface for programming/debugging without removing the flash chip

Repository Structure

RP2040-Embedded-Controller
│
├── Hardware
│   ├── KiCad          # Schematic + PCB project files (.kicad_sch, .kicad_pcb, .kicad_pro)
│   ├── PDFs           # Exported schematic/PCB PDFs
│   ├── Gerbers        # Manufacturing files (Gerbers + drill files)
│   └── BOM            # Bill of materials
│
├── Images
│   ├── PCB_Top_3D.png
│   ├── PCB_Bottom.png
│   ├── PCB_Layout.png
│   ├── Schematic_Power.png
│   └── Schematic_MCU.png
│
├── README.md
└── LICENSE

Future Improvements

• PCB fabrication and assembly
• Hardware bring-up and validation
• Firmware development using the Pico SDK
• OLED graphics library integration
• Retro game framework
• Battery management (charging + fuel gauge)
• Audio output
• Enclosure design

Tools Used

• KiCad 10
• Raspberry Pi RP2040 Datasheet
• Texas Instruments WEBENCH (buck converter design)
• Winbond W25Q128JVSIQ Datasheet

Learning Outcomes

This project provided hands-on experience in:

• Embedded hardware design
• Component selection and datasheet interpretation
• Switching power supply design
• RP2040 minimum-system implementation
• PCB layout and routing
• Signal integrity considerations
• Design for manufacturability (DFM)

Author

Susindharan S

Electrical & Electronics Engineering

Interested in:

• Embedded Systems
• PCB Design
• IoT
• Firmware Development

License

This project is licensed under the MIT License.