Struct RibbonController

pub struct RibbonController<const BUFFER_CAPACITY: usize> { /* private fields */ }

A synthesizer ribbon controller is represented here.

It is expected to use the provided sample_rate_to_capacity(sr) const function to calculate the const generic BUFFER_CAPACITY argument. If in the future Rust offers a way to calculate the buffer capacity in a more straightforward way this should be changed.

Implementations

impl<const BUFFER_CAPACITY: usize> RibbonController<BUFFER_CAPACITY>

pub fn new( sample_rate_hz: f32, softpot_ohms: f32, dropper_resistor_ohms: f32, pullup_resistor_ohms: f32, ) -> Self

Ribbon::new(sr, sp, dr, pu) is a new Ribbon controller

Arguments:

• sample_rate_hz - The sample rate in Hertz

• softpot_ohms - The end-to-end resistance of the softpot used, typically 10k or 20k

• dropper_resistor_ohms - The value of the resistor which sits between the top of the softpot and the positive voltage reference.

• pullup_resistor_ohms - The value of the wiper pullup reistor, shoudl be at least 10x softpot_ohms or larger

pub fn poll(&mut self, raw_adc_value: f32)

rib.poll(raw_adc_value) updates the controller by polling the raw ADC signal. Must be called at the sample rate

Arguments

• raw_adc_value - the raw ADC signal to poll in [0.0, 1.0], represents the finger position on the ribbon. Inputs outside of the range [0.0, 1.0] are undefined. Note that a small portion of the range at the top near +1.0 is expected to be “eaten” by the series resistor

pub fn value(&self) -> f32

rib.value() is the current position value of the ribbon in [0.0, 1.0]

If the user’s finger is not pressing on the ribbon, the last valid value before they lifted their finger is returned.

The value is expanded to take up the whole [0.0, 1.0]range, so even though the input will not quite reach +1.0 at the top end (due to the series resistance) the output will reach or at least come very close to +1.0

pub fn finger_is_pressing(&self) -> bool

rib.finger_is_pressing() is true iff the user is pressing on the ribbon.

pub fn finger_just_pressed(&mut self) -> bool

rib.finger_just_pressed() is true iff the user has just pressed the ribbon after having not touched it.

Self clearing

pub fn finger_just_released(&mut self) -> bool

rib.finger_just_released() is true iff the user has just lifted their finger off the ribbon.

Self clearing