# Crate pid

Expand description

A proportional-integral-derivative (PID) controller library.

See Pid for the adjustable controller itself, as well as ControlOutput for the outputs and weights which you can use after setting up your controller. Follow the complete example below to setup your first controller!

## Example

``````use pid::Pid;

// Create a new proportional-only PID controller with a setpoint of 15
let mut pid = Pid::new(15.0, 100.0);
pid.p(10.0, 100.0);

// Input a measurement with an error of 5.0 from our setpoint
let output = pid.next_control_output(10.0);

// Show that the error is correct by multiplying by our kp
assert_eq!(output.output, 50.0); // <--
assert_eq!(output.p, 50.0);

// It won't change on repeat; the controller is proportional-only
let output = pid.next_control_output(10.0);
assert_eq!(output.output, 50.0); // <--
assert_eq!(output.p, 50.0);

// Add a new integral term to the controller and input again
pid.i(1.0, 100.0);
let output = pid.next_control_output(10.0);

// Now that the integral makes the controller stateful, it will change
assert_eq!(output.output, 55.0); // <--
assert_eq!(output.p, 50.0);
assert_eq!(output.i, 5.0);

// Add our final derivative term and match our setpoint target
pid.d(2.0, 100.0);
let output = pid.next_control_output(15.0);

// The output will now say to go down due to the derivative
assert_eq!(output.output, -5.0); // <--
assert_eq!(output.p, 0.0);
assert_eq!(output.i, 5.0);
assert_eq!(output.d, -10.0);``````

## Structs

Output of controller iterations with weights