Apache NuttX is a mature, real-time embedded operating system (RTOS) https://nuttx.apache.org/
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Justin Hammond 1757b28b1f drivers/sensors: Use sensor_data_t for the electrical quantities.
The voltage, current, power, resistance and conductivity messages
declare their measurement as float, where every other message in
uorb.h declares it as sensor_data_t.  That type is b16_t under
CONFIG_SENSORS_USE_B16 and float otherwise, so on a fixed point
configuration these five are the only sensors still producing floats.

A driver that computes in sensor_data_t, as the helpers in fixedmath.h
encourage, then assigns a b16_t to a float field: the raw fixed point
integer is stored as a float and the reading is wrong by 65536 with no
diagnostic.

The accumulators keep int64_t.  Energy in uJ and charge in uC are
counts of micro units rather than measurements, and neither is
affected by the fixed point option.

Assisted-by: Claude:claude-opus-5
Signed-off-by: Justin Hammond <justin@dynam.ac>
2026-09-20 09:23:37 -04:00
.github ci: apply Depends-On dependencies to the memory report 2026-09-15 08:47:25 -03:00
arch arch/arm/stm32: implement PTP hardware clock driver (/dev/ptp0) 2026-09-19 18:32:45 -03:00
audio audio: limit the buffer count guard to shared ring requests 2026-08-05 07:58:53 +02:00
binfmt libs/libc/elf, binfmt: Describe the GOT by base and size, not by index. 2026-09-08 16:31:16 -03:00
boards boards: stm32g4: regenerate nucleo-g431kb comp defconfig 2026-09-19 22:41:17 +08:00
cmake cmake: fix undefined function name in parse args error messages 2026-09-11 21:15:22 +08:00
crypto crypto: fix chacha constants under GCC 15. 2026-09-20 08:22:11 -03:00
Documentation Documentation/ptp: correct the PTP clock driver page. 2026-09-20 08:22:33 -03:00
drivers drivers/timers: Add TMRDEPPATH/TMRVPATH for PTP clock drivers. 2026-09-19 18:32:45 -03:00
dummy
fs fs/inode: bound fdlist_extend() against the requested row 2026-09-17 13:50:27 +08:00
graphics graphics/nxterm: consume SGR escape sequences 2026-08-23 10:46:02 +08:00
include drivers/sensors: Use sensor_data_t for the electrical quantities. 2026-09-20 09:23:37 -04:00
libs libc/atexit: honor registrations made during exit processing 2026-09-14 18:52:46 -03:00
mm mm/iob: fix CONFIG_NET_TIMESTAMPING typo in iob_alloc 2026-09-19 16:36:47 -03:00
net net/pkt: remove unused variable conn in append_timestamping 2026-09-19 18:32:45 -03:00
openamp cmake: Use NUTTX(_DIR/_BIN_DIR) instead CMAKE(_SRC_DIR/_BIN_DIR) 2026-08-09 11:13:08 -03:00
pass1 tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-07-28 21:26:03 -03:00
sched sched/clock: update wall time on tickless tick and support slew limit PPM 2026-09-18 09:30:22 +08:00
syscall fs: rename PSEUDOFS_SOFTLINKS to FS_LINKS 2026-08-27 01:12:33 +08:00
tools tools/imxrt1180: Add a standalone C program for simple AHAB container creation 2026-09-19 22:38:45 +08:00
video video/videomode: Fix EDID parsing and formatting of video mode dumps 2026-08-29 11:09:11 -03:00
wireless wireless/bluetooth: Validate lengths when parsing advertising reports. 2026-09-19 18:30:43 -03:00
.asf.yaml github: master branch protection tune. 2025-05-07 18:37:13 -05:00
.codespell-ignore-lines arch/arm: Reserve r10 via ARCHCFLAGS and hoist the PIC module flags. 2026-07-24 23:09:08 +08:00
.codespellrc Revert "zbus: Add linker support and documentation for the zbus port" 2026-08-30 10:45:19 -03:00
.editorconfig .editorconfig: fix character encoding property specification 2025-11-28 19:12:13 +08:00
.gitignore boards/risc-v/eic7700x: Adopt the common board layout. 2026-08-19 01:40:57 +08:00
.gitmessage docs/contributing: Add a commit message template 2025-06-03 17:33:24 +08:00
.pre-commit-config.yaml pre-commit: enable codespell checks 2025-05-05 12:34:39 +08:00
.yamllint
AUTHORS AUTHORS: add Jorge Guzman 2026-08-25 08:43:13 -04:00
CMakeLists.txt cmake: reconfigure when .config changes 2026-09-14 18:40:45 -03:00
CONTRIBUTING.md contributing: Add requirement for 'Assisted-by' commit field 2026-07-12 09:42:28 +08:00
INVIOLABLES.md
Kconfig include/nuttx: Add link-time iterable sections infrastructure 2026-08-27 01:04:05 +08:00
LICENSE libs/libdsp: Add Matrix operations 2026-07-11 14:55:59 -03:00
Makefile !boards: enforce secure ROMFS passwd and TEA key setup 2026-07-09 22:41:11 +08:00
NOTICE
README.md ci/testing: Add MemBrowse Integration 2026-06-18 12:07:41 -03:00
ReleaseNotes Documentation: move ReleaseNotes 2023-09-26 20:41:00 +08:00

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Apache NuttX is a real-time operating system (RTOS) with an emphasis on standards compliance and small footprint. Scalable from 8-bit to 64-bit microcontroller environments, the primary governing standards in NuttX are POSIX and ANSI standards. Additional standard APIs from Unix and other common RTOSs (such as VxWorks) are adopted for functionality not available under these standards, or for functionality that is not appropriate for deeply-embedded environments (such as fork()).

For brevity, many parts of the documentation will refer to Apache NuttX as simply NuttX.

Getting Started

First time on NuttX? Read the Getting Started guide! If you don't have a board available, NuttX has its own simulator that you can run on terminal.

Documentation

You can find the current NuttX documentation on the Documentation Page.

Alternatively, you can build the documentation yourself by following the Documentation Build Instructions.

The old NuttX documentation is still available in the Apache wiki.

Supported Boards

NuttX supports a wide variety of platforms. See the full list on the Supported Platforms page.

Contributing

If you wish to contribute to the NuttX project, read the Contributing guidelines for information on Git usage, coding standard, workflow and the NuttX principles.

License

The code in this repository is under either the Apache 2 license, or a license compatible with the Apache 2 license. See the License Page for more information.