Skip to content

HARDWARE.md

Latest commit

 

History

History
46 lines (30 loc) · 2.36 KB

HARDWARE.md

File metadata and controls

46 lines (30 loc) · 2.36 KB
Raw

Hardware Overview

V2 Single-Board Reader (RP2040)

The V2 board is a single PCB integrating an N64 cartridge slot and a Raspberry Pi Pico (RP2040). It replaces the original Arduino Mega 2560 + shield design with a simpler, lower-cost solution.

Design Highlights

  • 3.3V-native: The RP2040 and N64 cartridges both operate at 3.3V. No level shifters required.
  • No SD card: All data transfer happens over USB. Saves and ROMs are streamed directly to the host.
  • Low BOM: The minimum build requires the PCB, a Pico, the N64 cartridge slot connector, and passive components.
  • USB-powered: No external power supply needed.

Pin Mapping

The RP2040 GPIO assignments are defined in firmware/rp2040/include/n64/pins.h.

Function GPIO N64 Slot Pin Notes
AD0-AD15 GPIO 0-15 AD0-AD15 16-bit multiplexed address/data bus
SYSTEM_RESET GPIO 16 RESET Active-high for bus reset
/WRITE GPIO 17 /WR Active-low write strobe
/READ GPIO 18 /RD Active-low read strobe
ALE_H GPIO 19 ALE_H Address latch enable (high byte)
ALE_L GPIO 20 ALE_L Address latch enable (low byte)
EEPROM DATA GPIO 21 EE_DAT Shared Joybus data line for cartridge EEPROM/RTC and controller
EEPROM CLK GPIO 22 EE_CLK Clock for cartridge EEPROM transfers

Power

  • VCC (3.3V): Supplied from the Pico's onboard regulator or an external 3.3V LDO (e.g. AP2112K-3.3) fed from USB 5V.
  • GND: Shared ground between Pico, PCB, and cartridge slot.

If using an external LDO, ensure solid solder joints on all pins — a high-resistance connection on the regulator can cause voltage sag under load, resulting in save write failures while reads appear normal.

KiCad Source

The schematic and PCB layout are in hardware/board/kicad/. Custom footprints for the N64 cartridge slot, controller port, and Pico module are in the project-local library under hardware/board/kicad/lib/.

Controller Port

The optional controller port shares the Joybus data line (GPIO 21) with EEPROM cartridges. When both are connected, bus contention will occur. Use one at a time.

Legacy Hardware

The original V1 design used an Arduino Mega 2560 with a shield PCB, SD card, and level shifters. See V1_LEGACY.md for details. V1 hardware files are preserved in the legacy/v1-arduino branch.