remotejoy-minus standalone

This is the RP2040-zero standalone version of remotejoy, with the video output function removed and enabling control via PS1/PS2 controllers.
By combining it with the external output function of the PSP-2000/3000, remote play using a TV screen is possible without a PC.
Does not require psplink.prx or usbhostfs.prx on the PSP side.

Build PSP Plugin

Set PSPDEV/PATH if needed, then run:

make

The output is:

remotejoy-minus.prx

Diagnostic log build:

make clean
make RJM_ENABLE_LOG=1

The diagnostic build writes ms0:/rjm_standalone.log. The normal build does not write a log file.

Build RP2040-zero Firmware

The direct PSP USB host firmware is in:

rp2040-zero/

Build it with Pico SDK from this directory:

cd rp2040-zero
mkdir -p build
cd build
cmake .. -DPICO_SDK_PATH=/path/to/pico-sdk
make

The output UF2 is:

rp2040-zero/build/remotejoy_minus_standalone_usbhost.uf2

For wiring instructions between the RP2040-zero and a PS1/PS2 controller, please refer to ./rp2040-zero/README.md.

Install

Write the firmware (.uf2) to RP2040-zero.

On the PSP side, copy remotejoy-minus.prx to the seplugins folder and add the following lines to VSH.txt/GAME.txt/POPS.txt as appropriate.

ms0:/seplugins/remotejoy-minus.prx

Enable the plugin from the PSP recovery menu.
Do not enable remotejoy.prx or RmoteJoyLite.prx because they conflict.

Acknowledgments

This implementation is based on the PSPLINKUSB/RemoteJoy controller protocol and USBHostFS-style endpoint layout. The PSP-side input injection logic is derived from the original RemoteJoy approach and then reduced to input-only operation.

RemoteJoyLite by Kethen was used as a technical reference for the standalone USB PRX structure, controller hook strategy, and POPS behavior.

The RP2040-zero firmware uses Pico SDK and TinyUSB as build/runtime dependencies.

License

remotejoy-minus is be distributed under the same BSD license as PSPLINKUSB.
This tree includes code, protocol definitions, and implementation structure derived from PSPLINKUSB RemoteJoy and usbhostfs, so the PSPLINKUSB BSD copyright notice, license conditions, and disclaimer must be preserved when redistributing source or binaries.

In particular, remotejoy.h is copied from the original RemoteJoy source and retains its own license header.

The RP2040-zero firmware links against Pico SDK and TinyUSB. When distributing RP2040-zero source or UF2 binaries, also comply with the license terms of those projects.