#stepper-motor #real-time

no-std stepgen

Stepper motor speed ramp generator

3 releases

0.1.3 Jan 3, 2022
0.1.2 Sep 14, 2017
0.1.1 Sep 11, 2017

#658 in Embedded development


280 lines

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Stepper motor speed ramp generator.

Given acceleration, target speed and target step to stop at, generates acceleration or deceleration profile for the stepper motor, in the form of delays between steps.

Uses algorithm from "Generate stepper-motor speed pro les in real time" paper by David Austin.


use stepgen::Stepgen;

let mut stepper = Stepgen::new(1_000_000);

stepper.set_acceleration(1000 << 8).unwrap(); // 1000 steps per second per second
stepper.set_target_speed(800 << 8).unwrap(); // 800 steps per second (4 turns per second)
stepper.set_target_step(1000).unwrap(); // stop at step 1000

// Take 99 steps
for _ in 0..99 {
    println!("{}", stepper.next().unwrap());

assert_eq!(99, stepper.current_step());
assert_eq!(113621, stepper.current_speed());
assert_eq!(2242, (stepper.next().unwrap() + 128) >> 8); // delay for 100th step, rounded to the nearest integer

Note on numbers

In few APIs, stepgen keeps numbers as fixed-point numbers, using least significant 8 bits for the fractional part and the remaining bits for the integral part.


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Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

No runtime deps