Merge pull request #3014 from brunob45/pwm_input

Add PWM Input for STM32

embassy-stm32/src/timer/input_capture.rs

@@ -7,7 +7,7 @@ use core::task::{Context, Poll};
 
 use embassy_hal_internal::{into_ref, PeripheralRef};
 
-use super::low_level::{CountingMode, InputCaptureMode, InputTISelection, Timer};
+use super::low_level::{CountingMode, FilterValue, InputCaptureMode, InputTISelection, Timer};
 use super::{
     CaptureCompareInterruptHandler, Channel, Channel1Pin, Channel2Pin, Channel3Pin, Channel4Pin,
     GeneralInstance4Channel,
@@ -40,11 +40,9 @@ macro_rules! channel_impl {
             #[doc = concat!("Create a new ", stringify!($channel), " capture pin instance.")]
             pub fn $new_chx(pin: impl Peripheral<P = impl $pin_trait<T>> + 'd, pull_type: Pull) -> Self {
                 into_ref!(pin);
-                critical_section::with(|_| {
-                    pin.set_as_af_pull(pin.af_num(), AFType::Input, pull_type);
-                    #[cfg(gpio_v2)]
-                    pin.set_speed(crate::gpio::Speed::VeryHigh);
-                });
+
+                pin.set_as_af_pull(pin.af_num(), AFType::Input, pull_type);
+
                 CapturePin {
                     _pin: pin.map_into(),
                     phantom: PhantomData,
@@ -83,7 +81,7 @@ impl<'d, T: GeneralInstance4Channel> InputCapture<'d, T> {
         let mut this = Self { inner: Timer::new(tim) };
 
         this.inner.set_counting_mode(counting_mode);
-        this.set_tick_freq(freq);
+        this.inner.set_tick_freq(freq);
         this.inner.enable_outputs(); // Required for advanced timers, see GeneralInstance4Channel for details
         this.inner.start();
 
@@ -109,24 +107,6 @@ impl<'d, T: GeneralInstance4Channel> InputCapture<'d, T> {
         self.inner.get_channel_enable_state(channel)
     }
 
-    /// Set tick frequency.
-    ///
-    /// Note: when you call this, the max period value changes
-    pub fn set_tick_freq(&mut self, freq: Hertz) {
-        let f = freq;
-        assert!(f.0 > 0);
-        let timer_f = self.inner.get_clock_frequency();
-
-        let pclk_ticks_per_timer_period = timer_f / f;
-        let psc: u16 = unwrap!((pclk_ticks_per_timer_period - 1).try_into());
-
-        let regs = self.inner.regs_core();
-        regs.psc().write_value(psc);
-
-        // Generate an Update Request
-        regs.egr().write(|r| r.set_ug(true));
-    }
-
     /// Set the input capture mode for a given channel.
     pub fn set_input_capture_mode(&mut self, channel: Channel, mode: InputCaptureMode) {
         self.inner.set_input_capture_mode(channel, mode);
@@ -148,10 +128,13 @@ impl<'d, T: GeneralInstance4Channel> InputCapture<'d, T> {
     }
 
     fn new_future(&self, channel: Channel, mode: InputCaptureMode, tisel: InputTISelection) -> InputCaptureFuture<T> {
-        self.inner.enable_channel(channel, true);
-        self.inner.set_input_capture_mode(channel, mode);
+        // Configuration steps from ST RM0390 (STM32F446) chapter 17.3.5
+        // or ST RM0008 (STM32F103) chapter 15.3.5 Input capture mode
         self.inner.set_input_ti_selection(channel, tisel);
-        self.inner.clear_input_interrupt(channel);
+        self.inner.set_input_capture_filter(channel, FilterValue::NOFILTER);
+        self.inner.set_input_capture_mode(channel, mode);
+        self.inner.set_input_capture_prescaler(channel, 0);
+        self.inner.enable_channel(channel, true);
         self.inner.enable_input_interrupt(channel, true);
 
         InputCaptureFuture {

embassy-stm32/src/timer/low_level.rs

@@ -7,6 +7,8 @@
 //! The available functionality depends on the timer type.
 
 use embassy_hal_internal::{into_ref, Peripheral, PeripheralRef};
+// Re-export useful enums
+pub use stm32_metapac::timer::vals::{FilterValue, Sms as SlaveMode, Ts as TriggerSource};
 
 use super::*;
 use crate::pac::timer::vals;
@@ -274,6 +276,22 @@ impl<'d, T: CoreInstance> Timer<'d, T> {
         }
     }
 
+    /// Set tick frequency.
+    pub fn set_tick_freq(&mut self, freq: Hertz) {
+        let f = freq;
+        assert!(f.0 > 0);
+        let timer_f = self.get_clock_frequency();
+
+        let pclk_ticks_per_timer_period = timer_f / f;
+        let psc: u16 = unwrap!((pclk_ticks_per_timer_period - 1).try_into());
+
+        let regs = self.regs_core();
+        regs.psc().write_value(psc);
+
+        // Generate an Update Request
+        regs.egr().write(|r| r.set_ug(true));
+    }
+
     /// Clear update interrupt.
     ///
     /// Returns whether the update interrupt flag was set.
@@ -573,6 +591,16 @@ impl<'d, T: GeneralInstance4Channel> Timer<'d, T> {
     pub fn set_cc_dma_enable_state(&self, channel: Channel, ccde: bool) {
         self.regs_gp16().dier().modify(|w| w.set_ccde(channel.index(), ccde))
     }
+
+    /// Set Timer Slave Mode
+    pub fn set_slave_mode(&self, sms: SlaveMode) {
+        self.regs_gp16().smcr().modify(|r| r.set_sms(sms));
+    }
+
+    /// Set Timer Trigger Source
+    pub fn set_trigger_source(&self, ts: TriggerSource) {
+        self.regs_gp16().smcr().modify(|r| r.set_ts(ts));
+    }
 }
 
 #[cfg(not(stm32l0))]

embassy-stm32/src/timer/mod.rs

@@ -8,6 +8,7 @@ use embassy_sync::waitqueue::AtomicWaker;
 pub mod complementary_pwm;
 pub mod input_capture;
 pub mod low_level;
+pub mod pwm_input;
 pub mod qei;
 pub mod simple_pwm;
 

embassy-stm32/src/timer/pwm_input.rs

@@ -0,0 +1,114 @@
+//! 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_type: Pull,
+        freq: Hertz,
+    ) -> Self {
+        into_ref!(pin);
+
+        pin.set_as_af_pull(pin.af_num(), AFType::Input, pull_type);
+
+        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_type: Pull,
+        freq: Hertz,
+    ) -> Self {
+        into_ref!(pin);
+
+        pin.set_as_af_pull(pin.af_num(), AFType::Input, pull_type);
+
+        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)
+    }
+}

examples/stm32f1/src/bin/input_capture.rs

@@ -0,0 +1,52 @@
+#![no_std]
+#![no_main]
+
+use defmt::*;
+use embassy_executor::Spawner;
+use embassy_stm32::gpio::{Level, Output, Pull, Speed};
+use embassy_stm32::time::khz;
+use embassy_stm32::timer::input_capture::{CapturePin, InputCapture};
+use embassy_stm32::timer::{self, Channel};
+use embassy_stm32::{bind_interrupts, peripherals};
+use embassy_time::Timer;
+use {defmt_rtt as _, panic_probe as _};
+
+/// Connect PA2 and PC13 with a 1k Ohm resistor
+
+#[embassy_executor::task]
+async fn blinky(led: peripherals::PC13) {
+    let mut led = Output::new(led, Level::High, Speed::Low);
+
+    loop {
+        info!("high");
+        led.set_high();
+        Timer::after_millis(300).await;
+
+        info!("low");
+        led.set_low();
+        Timer::after_millis(300).await;
+    }
+}
+
+bind_interrupts!(struct Irqs {
+    TIM2 => timer::CaptureCompareInterruptHandler<peripherals::TIM2>;
+});
+
+#[embassy_executor::main]
+async fn main(spawner: Spawner) {
+    let p = embassy_stm32::init(Default::default());
+    info!("Hello World!");
+
+    unwrap!(spawner.spawn(blinky(p.PC13)));
+
+    let ch3 = CapturePin::new_ch3(p.PA2, Pull::None);
+    let mut ic = InputCapture::new(p.TIM2, None, None, Some(ch3), None, Irqs, khz(1000), Default::default());
+
+    loop {
+        info!("wait for rising edge");
+        ic.wait_for_rising_edge(Channel::Ch3).await;
+
+        let capture_value = ic.get_capture_value(Channel::Ch3);
+        info!("new capture! {}", capture_value);
+    }
+}

examples/stm32f1/src/bin/pwm_input.rs

@@ -0,0 +1,54 @@
+#![no_std]
+#![no_main]
+
+use defmt::*;
+use embassy_executor::Spawner;
+use embassy_stm32::gpio::{Level, Output, Pull, Speed};
+use embassy_stm32::time::khz;
+use embassy_stm32::timer::pwm_input::PwmInput;
+use embassy_stm32::{bind_interrupts, peripherals, timer};
+use embassy_time::Timer;
+use {defmt_rtt as _, panic_probe as _};
+
+/// Connect PA0 and PC13 with a 1k Ohm resistor
+
+#[embassy_executor::task]
+async fn blinky(led: peripherals::PC13) {
+    let mut led = Output::new(led, Level::High, Speed::Low);
+
+    loop {
+        info!("high");
+        led.set_high();
+        Timer::after_millis(300).await;
+
+        info!("low");
+        led.set_low();
+        Timer::after_millis(300).await;
+    }
+}
+
+bind_interrupts!(struct Irqs {
+    TIM2 => timer::CaptureCompareInterruptHandler<peripherals::TIM2>;
+});
+
+#[embassy_executor::main]
+async fn main(spawner: Spawner) {
+    let p = embassy_stm32::init(Default::default());
+    info!("Hello World!");
+
+    unwrap!(spawner.spawn(blinky(p.PC13)));
+
+    let mut pwm_input = PwmInput::new(p.TIM2, p.PA0, Pull::None, khz(10));
+    pwm_input.enable();
+
+    loop {
+        Timer::after_millis(500).await;
+        let period = pwm_input.get_period_ticks();
+        let width = pwm_input.get_width_ticks();
+        let duty_cycle = pwm_input.get_duty_cycle();
+        info!(
+            "period ticks: {} width ticks: {} duty cycle: {}",
+            period, width, duty_cycle
+        );
+    }
+}

examples/stm32f4/src/bin/pwm_input.rs

@@ -0,0 +1,54 @@
+#![no_std]
+#![no_main]
+
+use defmt::*;
+use embassy_executor::Spawner;
+use embassy_stm32::gpio::{Level, Output, Pull, Speed};
+use embassy_stm32::time::khz;
+use embassy_stm32::timer::pwm_input::PwmInput;
+use embassy_stm32::{bind_interrupts, peripherals, timer};
+use embassy_time::Timer;
+use {defmt_rtt as _, panic_probe as _};
+
+/// Connect PB2 and PA6 with a 1k Ohm resistor
+
+#[embassy_executor::task]
+async fn blinky(led: peripherals::PB2) {
+    let mut led = Output::new(led, Level::High, Speed::Low);
+
+    loop {
+        info!("high");
+        led.set_high();
+        Timer::after_millis(300).await;
+
+        info!("low");
+        led.set_low();
+        Timer::after_millis(300).await;
+    }
+}
+
+bind_interrupts!(struct Irqs {
+    TIM2 => timer::CaptureCompareInterruptHandler<peripherals::TIM2>;
+});
+
+#[embassy_executor::main]
+async fn main(spawner: Spawner) {
+    let p = embassy_stm32::init(Default::default());
+    info!("Hello World!");
+
+    unwrap!(spawner.spawn(blinky(p.PB2)));
+
+    let mut pwm_input = PwmInput::new(p.TIM3, p.PA6, Pull::None, khz(10));
+    pwm_input.enable();
+
+    loop {
+        Timer::after_millis(500).await;
+        let period = pwm_input.get_period_ticks();
+        let width = pwm_input.get_width_ticks();
+        let duty_cycle = pwm_input.get_duty_cycle();
+        info!(
+            "period ticks: {} width ticks: {} duty cycle: {}",
+            period, width, duty_cycle
+        );
+    }
+}