# `dcmimu`
> An algorithm for fusing low-cost triaxial MEMS gyroscope and accelerometer measurements.
A `no_std` Rust port of [the original](https://github.com/hhyyti/dcm-imu).
[](https://travis-ci.org/copterust/dcmimu)
*NOTE*: `libm` still [doesn't with overflow checks](https://github.com/japaric/libm/issues/4),
so you have to compile your project with `--release`.
Leave a comment in the linked issue to [raise awareness](https://www.youtube.com/watch?v=KbZIFZm204E).
## Credentials
[Heikki Hyyti and Arto Visala, "A DCM Based Attitude Estimation Algorithm for Low-Cost MEMS IMUs," International Journal of Navigation and Observation, vol. 2015, Article ID 503814, 18 pages, 2015](http://dx.doi.org/10.1155/2015/503814).
## Usage
Library is available via crates.io [](https://crates.io/crates/dcmimu).
```rust
# Create DCMIMU:
let mut dcmimu = DCMIMU::new();
let mut prev_t_ms = now();
loop {
# get gyroscope and accelerometer measurement from your sensors:
let gyro = sensor.read_gyro();
let accel = sensor.read_accel();
# Convert measurements to SI if needed.
# Get time difference since last update:
let t_ms = now();
let dt_ms = t_ms - prev_t_ms
prev_t_ms = t_ms
# Update dcmimu states (don't forget to use SI):
let dcm = dcmimu.update((gyro.x, gyro.y, gyro.z),
(accel.x, accel.y, accel.z),
dt_ms.seconds());
println!("Roll: {}; yaw: {}; pitch: {}", dcm.roll, dcm.yaw, dcm.pitch);
# Measurements can also be queried without updating:
println!("{:?} == {}, {}, {}", dcmimu.all(), dcmimu.roll(), dcmimu.yaw(), dcmimu.pitch());
}
```
Check out [mpu9250](https://crates.io/crates/mpu9250) for accelerometer/gyroscrope sensors driver.
## Documentation
Available via [docs.rs](https://docs.rs/dcmimu/).
## License
[MIT license](http://opensource.org/licenses/MIT).