This program intends to create a port of the NBC/NXC Enhanced Firmware to the EV3 programmable brick.
This project is pre-alpha, do expect bugs and crashes to occur.
| Component | Status | Comment |
|---|---|---|
| NXT VM | PARTIAL | carried over from NXT, some previously hidden bugs now cause segfaults |
| Buttons | mostly DONE | button press OK; TODO for LED control (needs new bytecode or IOMap) |
| Motors | partial DONE, not tested | reused NXT PID controller, PID coefficients need some tuning |
| Display | mostly DONE | needs configurable scaling + some sort of "damage" tracking to optimize flushes |
| Sound | DONE, WIP tests | sounds (PCM+ADPCM) tested, tones tested, melodies untested; full 2000-16000 Hz range supported by resampling to 8000 Hz |
| Sensors | PARTIAL | EV3 sensors emulate NXT ones; needs pure EV3 layer + IIC support + emulation of more sensors |
| Bluetooth | not started | RFCOMM connections + HCI |
| USB | PARTIAL | EV3 system commands work (ev3duder), NXT protocol tunnel mostly works |
| NXT driver | not started | emulate NXT as a USB device via USB/IP or other similar mechanism |
The spiritual predecessor of this project is the NXC4EV3 project. It's main goal was to create a NXC-to-C translator that would enable reusing source code between platforms. However, this turned out to be a complex task and there were multiple possible ways of developing the software forward.
This is where NXT3 comes in. The motivation behind it is to replace the transpiler with something that effectively is an emulator of the NXT. This theoretically allows for 100 % compatibility between the two bricks. It also enables one to use the existing BricxCC/NXC tooling to avoid the need to write a compiler of sorts.
NXT3 does not intend to be a catch-all solution, as some of the limitations of the NXT are unavoidable and dictated by the RXE file format. It intends to complement other programming solutions available for EV3:
- C4EV3, a native C/C++ programming environment for the EV3 stock firmware,
- ev3dev-lang-cpp, a native C++ library for the ev3dev firmware,
- Pybricks, a MicroPython-based programming environment for EV3, NXT (preview) and other platforms,
- and also the aforementioned NXC4EV3, a (somewhat unfinished) NXC-to-C4EV3 transpiler.
Since the core code comes straight from the NXT codebase, it falls under the LOSLA (LEGO® OPEN SOURCE LICENSE AGREEMENT 1.0 LEGO® MINDSTORMS® NXT FIRMWARE). See LICENSE.pdf for details. This also precludes using GPL'd components, so all code for interfacing with the EV3 kernel has to be written from scratch (C4EV3 is GPLv2.0, lms2012 is GPLv2.0).
libsamplerate is Copyright (c) 2012-2016, Erik de Castro Lopo erikd@mega-nerd.com and released under the BSD 2-clause license.
The original code for this port comes from the Mindboards SVN repository: https://sourceforge.net/p/mindboards/code/HEAD/tree/lms_nbcnxc/branches/version_132/
The HAL base and implementation layers are licensed under the MIT License.
The battd daemon in lms2012 HAL is licensed under GNU GPLv2.0 because it includes battery temperature estimation code from the stock firmware.