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OSCP IMU C Library

oscp-imu-c is a portable, dependency-light C library for communicating with OSCP MK2 IMU units. It decodes every operating frame the unit emits and encodes the full command set, over both transports the family supports: streamed RS422 and framed CAN-FD.

https://github.com/OSCPS/oscp-imu-c

Build & install

The library is small enough to drop straight into your build - no package manager required. Copy four files into your source tree and compile them alongside your own code.

What you need

Four files:

File From Role
oscp_imu.h repository root Library header
oscp_imu.c repository root Library implementation
cobs.h third-party/cobs-c/ Craig McQueen COBS dependency (header)
cobs.c third-party/cobs-c/ Craig McQueen COBS dependency (implementation)

Add it to your project

  1. Copy the four files into your source tree (e.g. a third-party/oscp-imu-c/ folder).
  2. Compile oscp_imu.c and cobs.c as part of your build.
  3. Add the folders holding oscp_imu.h and cobs.h to your include path.
  4. Include the one public header:
#include "oscp_imu.h"

That's the whole installation.

Requirements

A C compiler (GCC, Clang or MSVC) and a little-endian target (Cortex-M, x86, ARM64). Decoding is a memcpy into packed structs, which is correct only when host and wire byte orders match.

Big-endian targets fail to compile - by design

A #error guard in oscp_imu.h stops the build on big-endian hosts. To support one, replace the decode_* functions with explicit byte-swap helpers. Reach out to OSCP if you need this.

Why this library

  • Zero dynamic allocation

    All parser state lives in a caller-owned oscp_parser_t. Nothing uses malloc - safe for bare-metal and RTOS targets.

  • Two transports, one decoder

    A byte-stream parser for RS422 and a single stateless call for CAN-FD. Both produce the same oscp_frame_t.

  • Full frame coverage

    Raw, Euler, Quaternion, Rotation Matrix, GNSS, Debug 1/2 and Startup frames are decoded into typed structs.

  • Complete command set

    17 commands encoded for either transport, with enumerations for every argument.

  • Integrity built in

    CRC-16 validation on every frame, plus COBS framing on the RS422 path.

  • Genuinely portable

    Builds with GCC, Clang and MSVC. Runs on Cortex-M, x86 and ARM64.

Supported hardware

Model Description
MK2M2 OSCP Tactical-Grade MEMS IMU
MK2E2 OSCP Tactical-Grade MEMS + Optical Gyroscope IMU
MK2Z OSCP Navigation-Grade MEMS + Optical Gyroscope IMU

Documentation map

  • Integration Paths

    Choose between the RS422 byte-stream parser and the CAN-FD message decoder.

  • Frame Reference

    Every operating frame, field by field, with units and bytes layout.

  • Command Reference

    All 17 commands, their state classes, and the argument enumerations.

  • API Reference

    Every public function, type and return code in one place.

  • Examples

    Copy-paste starting points for RS422, CAN-FD and command transmission.

Version

This documentation tracks oscp-imu-c v0.2.0.