2024-06-16 21:11:55 +02:00

115 lines
3.5 KiB
Rust

//! PWM Input driver.
use embassy_hal_internal::into_ref;
use super::low_level::{CountingMode, InputCaptureMode, InputTISelection, SlaveMode, Timer, TriggerSource};
use super::{Channel, Channel1Pin, Channel2Pin, GeneralInstance4Channel};
use crate::gpio::{AfType, Pull};
use crate::time::Hertz;
use crate::Peripheral;
/// PWM Input driver.
pub struct PwmInput<'d, T: GeneralInstance4Channel> {
channel: Channel,
inner: Timer<'d, T>,
}
impl<'d, T: GeneralInstance4Channel> PwmInput<'d, T> {
/// Create a new PWM input driver.
pub fn new(
tim: impl Peripheral<P = T> + 'd,
pin: impl Peripheral<P = impl Channel1Pin<T>> + 'd,
pull: Pull,
freq: Hertz,
) -> Self {
into_ref!(pin);
pin.set_as_af(pin.af_num(), AfType::input(pull));
Self::new_inner(tim, freq, Channel::Ch1, Channel::Ch2)
}
/// Create a new PWM input driver.
pub fn new_alt(
tim: impl Peripheral<P = T> + 'd,
pin: impl Peripheral<P = impl Channel2Pin<T>> + 'd,
pull: Pull,
freq: Hertz,
) -> Self {
into_ref!(pin);
pin.set_as_af(pin.af_num(), AfType::input(pull));
Self::new_inner(tim, freq, Channel::Ch2, Channel::Ch1)
}
fn new_inner(tim: impl Peripheral<P = T> + 'd, freq: Hertz, ch1: Channel, ch2: Channel) -> Self {
let mut inner = Timer::new(tim);
inner.set_counting_mode(CountingMode::EdgeAlignedUp);
inner.set_tick_freq(freq);
inner.enable_outputs(); // Required for advanced timers, see GeneralInstance4Channel for details
inner.start();
// Configuration steps from ST RM0390 (STM32F446) chapter 17.3.6
// or ST RM0008 (STM32F103) chapter 15.3.6 Input capture mode
inner.set_input_ti_selection(ch1, InputTISelection::Normal);
inner.set_input_capture_mode(ch1, InputCaptureMode::Rising);
inner.set_input_ti_selection(ch2, InputTISelection::Alternate);
inner.set_input_capture_mode(ch2, InputCaptureMode::Falling);
inner.set_trigger_source(match ch1 {
Channel::Ch1 => TriggerSource::TI1FP1,
Channel::Ch2 => TriggerSource::TI2FP2,
_ => panic!("Invalid channel for PWM input"),
});
inner.set_slave_mode(SlaveMode::RESET_MODE);
// Must call the `enable` function after
Self { channel: ch1, inner }
}
/// Enable the given channel.
pub fn enable(&mut self) {
self.inner.enable_channel(Channel::Ch1, true);
self.inner.enable_channel(Channel::Ch2, true);
}
/// Disable the given channel.
pub fn disable(&mut self) {
self.inner.enable_channel(Channel::Ch1, false);
self.inner.enable_channel(Channel::Ch2, false);
}
/// Check whether given channel is enabled
pub fn is_enabled(&self) -> bool {
self.inner.get_channel_enable_state(Channel::Ch1)
}
/// Get the period tick count
pub fn get_period_ticks(&self) -> u32 {
self.inner.get_capture_value(self.channel)
}
/// Get the pulse width tick count
pub fn get_width_ticks(&self) -> u32 {
self.inner.get_capture_value(match self.channel {
Channel::Ch1 => Channel::Ch2,
Channel::Ch2 => Channel::Ch1,
_ => panic!("Invalid channel for PWM input"),
})
}
/// Get the duty cycle in 100%
pub fn get_duty_cycle(&self) -> f32 {
let period = self.get_period_ticks();
if period == 0 {
return 0.;
}
100. * (self.get_width_ticks() as f32) / (period as f32)
}
}