Copperpilot retro handheld

CopperPilot Retro Handheld: 4-Layer ESP32-S3 Handheld Console Hardware

The CopperPilot Retro Handheld is an ultra-compact, single-board retro handheld console design built on a 4-layer FR-4 PCB (63.00 mm x 80.00 mm) with a parametric snap-fit enclosure. Built around an Espressif ESP32-S3 dual-core microcontroller, the hardware features a 2.4-inch 320x240 ILI9341 SPI color TFT display, 14 responsive gameplay and shoulder pushbuttons, integrated USB-C charging and native USB-OTG/JTAG programming, automatic load-sharing battery power management for uninterrupted gameplay while charging, and a removable 1000 mAh Li-Po cell.

Project status: this repository contains the hardware (schematic, PCB, enclosure CAD, and manufacturing outputs) only. There is no firmware yet, so no frame rates, emulator compatibility, or battery runtime have been measured on this board.

3D Enclosure & Industrial Design Showcase

3D CAD Enclosure Renders

Front Face & Controls	Rear Shell & Grip Channels
Front bezel, display window & keycaps	Rear grooved shell & battery hatch

3/4 Isometric View	Exploded Subsystem Assembly
Assembled enclosure	Front Bezel, PCBA, Floating Keycaps, Rear Shell & Door

Complete 3D Assembly Motion Animation (GIF & MP4)

Sequential 3D Assembly Animation: PCBA SMT/TH Component Populating → Gamepad Keycaps Seating over Tactile Switches → 2.4" Display Panel Seating & FPC Interconnect into J3 → Front Bezel Lowering over Controls & Alignment Pins → Li-Po Battery Seating into Rear Cavity → Rear Grooved Shell Closing & Flush Snap Mating → 360° Watertight Turntable Inspection
High-definition MP4 video asset: docs/images/case_assembly_video.mp4

4-Layer Routed PCB Layout & Schematic Capture

Front Layer (F.Cu — Tactile Controls & Display)	Back Layer (B.Cu — ESP32-S3, USB-C & Power ICs)

Photorealistic 3D KiCad PCB Renders (kicad-cli pcb render)

KiCad 3D Top View (Tactile Controls, JST-GH J3 & Top Shoulder Switches)	KiCad 3D Bottom View (ESP32-S3 Module, USB-C, JST-PH & Power Management)
Populated Front: 14x Tactile Switches, J3 Display Receptacle, D1/D3 LEDs	Populated Back: ESP32-S3-WROOM-1, USB-C, JST-PH Battery Header, LDO & Charger

Complete 6-Block Schematic Capture (USB-C Power, Li-Po Charger, Load Sharing, ESP32-S3 Core, ILI9341 TFT & 14 Pushbuttons)

System Architecture

                    +-------------------------------------------------------+
                    |                   Power Subsystem                     |
                    | USB-C (J1) ---> USBLC6-2SC6 (U1) ESD Protection       |
                    |                 |                                     |
                    |                 +---> MCP73831 (U2) Charger (500mA)   |
                    |                 |     |                               |
                    |                 |     v                               |
                    |                 |    JST-PH 1S LiPo (J2)              |
                    |                 |     |                               |
                    |                 v     v                               |
                    |           AO3401A (Q1) + MBR0520 (D2) Power Path      |
                    |                       | (Auto Load-Sharing)           |
                    |                       v                               |
                    |              Main Power Switch (SW1)                  |
                    |                       |                               |
                    |                       +---> 100k/100k Divider (IO1)   |
                    |                       v                               |
                    |              AP2112K-3.3 (U3) 600mA LDO               |
                    +-----------------------|-------------------------------+
                                            | +3.3V System Rail
+--------------------------+  Hardware FSPI +-------------------------------+
|  2.4" 320x240 ILI9341    |<---------------|       ESP32-S3-WROOM-1        |
|  SPI Color TFT (J3)      |  SCK, MOSI,    |  Dual-Core Xtensa LX7 240MHz  |
|  2N7002 Backlight Driver |<---------------|  512KB SRAM, 8MB Flash        |

Hardware Specifications & Computational Capability

• Chassis & Form Factor: 63.00 mm x 80.00 mm ultra-compact 4-layer FR-4 PCB with R=2.50 mm corner radii, 4 precision 2.20 mm alignment holes (H1–H4), and 4 through-PCB snap-hook retention notches (SL1, SL2, SR1, SR2).
• Core Processing Unit: Espressif ESP32-S3-WROOM-1-N8R2 (dual-core 32-bit Xtensa LX7 @ 240 MHz, 512 KB internal SRAM, 8 MB Quad-SPI Flash, 2 MB Quad-SPI PSRAM, 2.4 GHz 802.11 b/g/n Wi-Fi + Bluetooth 5.0 LE).
  • Game & Emulator Capability (not yet verified on this board): There is no firmware for this board yet, so no frame rates or emulator results are claimed here. The figures below are design-level estimates and third-party reports from other ESP32-S3 hardware, cited for reference only:
    • Display link: the ESP32-S3 SPI2 (FSPI) peripheral supports DMA transfers. A full 320x240 RGB565 frame is 150 KB (300 KB double-buffered, well within the 2 MB PSRAM). Achievable frame rate depends on the SPI clock the ILI9341 panel and cabling sustain in practice (commonly 40 MHz). The esp-box-emu project reports a "~31 fps ceiling" for 320x240x16bpp output on its ESP32-S3 panel.
    • Emulators on other ESP32-S3 devices: esp-box-emu runs NES (nofrendo), Game Boy / Game Boy Color (gnuboy), Sega Master System / Game Gear, Genesis and Doom on the ESP32-S3-BOX. Retro-Go supports NES, Game Boy / Color, Master System, Game Gear, PC Engine and more on ESP32 handhelds, with ESP32-S3 community ports. PaperBoy S3 (Tom's Hardware) runs a Game Boy emulator on an ESP32-S3, with the chip fully loaded.
    • These results come from different hardware and firmware. Performance on this board has to be measured once firmware exists.
    • Audio note: The board does not integrate an analog audio amplifier or speaker. Audio is supported wirelessly via Bluetooth 5.0 LE / A2DP or via external PWM buzzer on spare GPIO.
• Display Subsystem & Connector J3:
  • Board-Mounted SMT Socket (J3): JST Sales America SM10B-GHS-TB(LF)(SN) (10-position 1.25 mm pitch horizontal SMD header with solder retention tabs).
  • Turnkey Sourced Display Module (DISP1): Waveshare 15933 (MPN: 15933 / DigiKey: 2649-15933-ND / LCSC: C2913222) or EastRising ER-TFT024-3.
    • 2.4-inch 320x240 RGB TFT LCD, Sitronix/Ilitek ILI9341 4-wire SPI controller, 3.3V DC logic, active area 48.96 x 36.72 mm, 10-conductor cable harness with mating plug JST GHR-10V-S.
  • Onboard 2N7002 N-channel MOSFET backlight switch (Q2) with 10 Ω ballast resistor (R14) and 100 kHz PWM brightness dimming on GPIO21.
• Power Management & Dynamic Load-Sharing:
  • Microchip MCP73831T-2ACI/OT linear Li-Po/Li-Ion charge management controller configured for 500 mA fast charge (R_PROG = 2.0 kΩ 1%).
  • Automatic dynamic load sharing via AO3401A P-channel MOSFET (Q1, $R_{DS(on)} < 50\text{ m}\Omega$) and MBR0520 Schottky barrier diode (D2, $V_F = 0.38\text{ V}$). When 5V USB-C is plugged in, the system runs directly off USB power while the battery charges undisturbed at its full C-rate; upon disconnect, the MOSFET transparently switches system load back to battery without voltage droop.
  • Diodes Inc. AP2112K-3.3 ultra-low-dropout 600 mA CMOS regulator with 250 mV dropout voltage, powering the console reliably down to 3.55 V battery cutoff.
  • Precision 100 kΩ / 100 kΩ 1% resistor divider (R8, R9) with 100 nF smoothing capacitor (C6) on ESP32-S3 ADC1_CH0 (GPIO1) for fuel gauge battery telemetry.
  • Estimated system consumption (design estimate, not measured): ~220 mA @ 3.3V (~0.73W) with display backlight at 100% and CPU at 240 MHz, which would give roughly 4.5 hours from a 1000 mAh Li-Po cell.
• Controls & Non-Colliding 3D Keycaps:
  • 14 front-mounted tactile switches with 10 kΩ pull-up networks:
    • 4-way D-Pad (UP, DOWN, LEFT, RIGHT) centered at (14.65, 60.96 mm).
    • 4-button action diamond (A, B, X, Y) centered at (47.97, 61.75 mm).
    • 2 utility buttons (SELECT, START) centered at (31.24, 69.70 mm).
    • 4 shoulder triggers (L1, L2, R1, R2) centered at (9.50, 18.33, 53.50, 44.67 mm).
  • Guaranteed Physical Clearances:
    • D-Pad to Select button flange clearance: 1.49 mm (zero collision).
    • ABXY adjacent button flange clearance: >1.22 mm between all neighboring pairs.
    • L1/L2 and R2/R1 shoulder trigger gap: 0.93 mm inter-button clearance.
    • Keycap-to-bezel sliding clearance: 0.30 mm radial clearance for friction-free actuation.

Lion Circuits 4-Layer Manufacturing & PCBA Specifications

The hardware has been validated against Lion Circuits India turnkey PCBA design and procurement standards:

Turnkey PCBA Bill of Materials (45 Verified Line Items)

Automated Verification Suite

The repository includes a 51-point automated PyTest hardware, assembly, and enclosure verification suite:

$ make test
============================= test session starts ==============================
platform linux -- Python 3.13.9, pytest-9.1.1
collected 51 items

tests/test_assembly_e2e.py::TestEndToEndAssemblySequence::test_stage1_pcba_component_loading PASSED
tests/test_assembly_e2e.py::TestEndToEndAssemblySequence::test_stage2_kicad_3d_pcba_mesh_validation PASSED
tests/test_assembly_e2e.py::TestEndToEndAssemblySequence::test_stage3_buttons_clearance_and_zero_collision PASSED
tests/test_assembly_e2e.py::TestEndToEndAssemblySequence::test_stage4_buttons_seat_onto_pcba_zero_collision PASSED
tests/test_assembly_e2e.py::TestEndToEndAssemblySequence::test_stage5_buttons_seat_in_front_bezel_zero_collision PASSED
tests/test_assembly_e2e.py::TestEndToEndAssemblySequence::test_stage6_display_shelf_mating_and_j3_interconnect PASSED
tests/test_assembly_e2e.py::TestEndToEndAssemblySequence::test_stage7_pcba_mating_to_front_bezel_zero_collision PASSED
tests/test_assembly_e2e.py::TestEndToEndAssemblySequence::test_stage8_rear_shell_mating_over_pcb_zero_collision PASSED
tests/test_assembly_e2e.py::TestEndToEndAssemblySequence::test_stage9_battery_seating_and_rear_cavity_fit PASSED
tests/test_assembly_e2e.py::TestEndToEndAssemblySequence::test_stage10_continuous_kinematic_assembly_trajectories PASSED
tests/test_assembly_e2e.py::TestEndToEndAssemblySequence::test_stage11_full_console_assembly_envelope PASSED
tests/test_case.py::TestCaseFiles::test_stl_file_exists[case_front_bezel.stl] PASSED
tests/test_case.py::TestCaseFiles::test_stl_file_exists[case_rear_grooved.stl] PASSED
tests/test_case.py::TestCaseFiles::test_stl_file_exists[case_battery_door.stl] PASSED
tests/test_case.py::TestCaseFiles::test_stl_file_exists[buttons_dpad_abxy_sest_shoulders.stl] PASSED
tests/test_case.py::TestCaseFiles::test_stl_file_exists[copperpilot_retro_handheld_assembly.stl] PASSED
tests/test_case.py::TestCaseGeometry::test_front_bezel_envelope PASSED
tests/test_case.py::TestCaseGeometry::test_rear_shell_envelope PASSED
tests/test_case.py::TestCaseGeometry::test_battery_door_envelope PASSED

Repository Structure

.
├── Makefile                            # Top-level orchestrator (test, drc, erc, fab, gerbers)
├── .gitignore                          # Comprehensive Git exclusion rules
├── LICENSE                             # CERN Open Hardware Licence v2 - Permissive
├── README.md                           # Master hardware, pinout, and manufacturing documentation
├── export_manufacturing.py             # Lion Circuits release generator (Gerbers, CPL, BOM, D356)
├── copperpilot-retro-handheld.kicad_pro       # KiCad 10 project definition & netclass rules
├── copperpilot-retro-handheld.kicad_sch       # Hierarchical schematic capture (0 ERC errors)
├── copperpilot-retro-handheld.kicad_pcb       # 4-layer PCB layout (100% routed, 0 DRC violations)
├── sym-lib-table                       # Symbol library mapping
├── fp-lib-table                        # Footprint library mapping
├── libs/                               # Custom symbols and footprints
│   ├── copperpilot_retro_handheld.kicad_sym      # Custom ILI9341 2.4" TFT display symbol
│   └── copperpilot_retro_handheld.pretty/        # Custom 10-pin display footprint & 3D model
├── tests/                              # Automated 51-point hardware & assembly verification suite
│   ├── conftest.py                     # S-expression AST parsers & KiCad CLI fixtures
│   ├── test_assembly_e2e.py            # 11-stage end-to-end mechanical assembly verification
│   ├── test_pcb.py                     # 25-point PCB geometry, connectivity, DFM & circuit tests
│   └── test_case.py                    # 15-point 3D mechanical enclosure & clearance tests
├── case/                               # Parametric 3D snap-fit enclosure CAD subsystem
│   ├── Makefile                        # Targets: generate, render, test, clean
│   ├── README.md                       # Enclosure mechanics, snap-fit physics & 3D print specs
│   ├── generate_case.py                # Parametric CSG mesh synthesis in Trimesh & Manifold3D
│   ├── render_case.py                  # High-resolution PyVista rendering & animation engine

Quickstart & Manufacturing Commands

Ensure kicad-cli (v10.0+) and Python 3.10+ (with uv) are available in your path:

1. Run Automated Verification & Rule Checks

# Run full 51-point PyTest verification suite (installs test deps via uv)
make test

# Run electrical rule check (ERC) via KiCad CLI
kicad-cli sch erc copperpilot-retro-handheld.kicad_sch

# Run design rule check (DRC) via KiCad CLI
kicad-cli pcb drc copperpilot-retro-handheld.kicad_pcb

2. Generate 3D CAD Enclosure STLs and Visuals

# Generate watertight STL models
make build-case

# Render smooth anti-aliased images and assembly animation
make render-case

3. Generate Turnkey Manufacturing Release Bundle

# Generate gerbers, drill, CPL, structured BOM, and release zip
make fab