nsnds

Software to use your Nintendo DSi and Raspberry Pi Pico W as a controller for a Nintendo Switch or Steam.

Requirements

• A Nintendo DSi with a way to boot a ROM
• A Raspberry Pi Pico W

Setup

• Install devkitPro
• Install the Arduino IDE and the rp2040 core (version 2.6.5)
• Copy boards.local.txt to your RP2040 folder (%LOCALAPPDATA%\Arduino15\packages\rp2040\hardware\rp2040\2.6.5\ for Windows)
• Set Tools->USB Stack to Adafruit TinyUSB in the Arduino IDE
• MANUALLY configure the ONLY available network on the Nintendo DS to have the following options:
  • SSID: value of NSNDS_SSID in nsnds.h (default: nsnds)
  • Security: None
  • IP Address: 192.168.42.16
  • Subnet Mask: 255.255.255.0
  • Gateway: 192.168.42.1
  • Primary DNS: 8.8.8.8
  • Secondary DNS: 8.8.4.4
  • MTU Value: 1400
  • The connection test is supposed to fail
  • I'm not sure which of these values are necessary, but they work so I'm not touching them
• Run make in the terminal (Unix) or in MSys2 (Windows) to build the DS ROM (nsnds.nds), then move it to your SD card.
• Open pico as a sketch in the Arduino IDE and upload it to your Pico W.

Usage

1. Plug in the Pico W to a Nintendo Switch or PC
2. Launch the ROM on the Nintendo DS WHILE the Pico W is plugged in and the Nintendo Switch or PC is on

The connection will break when the Nintendo Switch goes into sleep mode or after a while if too many Bluetooth controllers are connected. In such a case, just restart the ROM on the DS.