Crate stepgen[][src]

Expand description

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 {

assert_eq!(99, stepper.current_step());
assert_eq!(113621, stepper.current_speed());
assert_eq!(2242, ( + 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.


State of the stepgen.


Error code for some of the stepgen operations.

Type Definitions

Result type for some of the stepgen operations.