Gravity-Free X-Y Acceleration
Budget / Salary₹5,000–8,000
TypeFreelance project
LocationRemote
Posted1 hour ago
Firmware Development:
I have an ISM330DHCX IMU on the I2C bus of an STM32H745Zi board. Register access is already running; what I need is the maths.
Your task is to fuse the IMU’s gyroscope and accelerometer so the MCU keeps an accurate estimate of its attitude and continuously subtracts the gravity vector. The end result must be two real-time, gravity-free linear acceleration values for the X and Y axes only.
The code will sit in a small autonomous-vehicle controller, so it has to stay responsive during sustained vibrations, pothole like movements and slow tilting during slopes and hills—not just brief hand motions. Please keep latency low enough for a 400 Hz control loop and write everything in clean C that compiles inside STM32CubeIDE with HAL drivers.
Deliverables
• C source and header files implementing the orientation filter and gravity compensation
• A simple example task that prints the gravity-free X and Y acceleration over UART every cycle
• Short README explaining configuration registers, sampling rate, coordinate frames and any calibration steps
Delivery date: 22/11/26 till 10PM
Acceptance: when the board is held at any tilt while stationary, reported X-Y acceleration remains within ±0.02 g, and when the platform is driven in a straight 1 m/s² sled test it reports ≈1 m/s².
I have an ISM330DHCX IMU on the I2C bus of an STM32H745Zi board. Register access is already running; what I need is the maths.
Your task is to fuse the IMU’s gyroscope and accelerometer so the MCU keeps an accurate estimate of its attitude and continuously subtracts the gravity vector. The end result must be two real-time, gravity-free linear acceleration values for the X and Y axes only.
The code will sit in a small autonomous-vehicle controller, so it has to stay responsive during sustained vibrations, pothole like movements and slow tilting during slopes and hills—not just brief hand motions. Please keep latency low enough for a 400 Hz control loop and write everything in clean C that compiles inside STM32CubeIDE with HAL drivers.
Deliverables
• C source and header files implementing the orientation filter and gravity compensation
• A simple example task that prints the gravity-free X and Y acceleration over UART every cycle
• Short README explaining configuration registers, sampling rate, coordinate frames and any calibration steps
Delivery date: 22/11/26 till 10PM
Acceptance: when the board is held at any tilt while stationary, reported X-Y acceleration remains within ±0.02 g, and when the platform is driven in a straight 1 m/s² sled test it reports ≈1 m/s².
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