HRTIM: Capture example

Author: usbalbin

examples/hrtim/capture.rs

@@ -0,0 +1,103 @@
+#![no_std]
+#![no_main]
+
+use cortex_m_rt::entry;
+
+use defmt_rtt as _; // global logger
+use panic_probe as _;
+
+#[entry]
+fn main() -> ! {
+    use stm32g4xx_hal as hal;
+
+    use defmt::info;
+    use hal::{
+        gpio::{gpioa::PA8, Alternate, GpioExt, AF13},
+        hrtim::{
+            capture::HrCapture, compare_register::HrCompareRegister, control::HrControltExt,
+            external_event, external_event::ToExternalEventSource, output::HrOutput,
+            timer::HrTimer, HrPwmAdvExt, Pscl4,
+        },
+        pwm,
+        pwr::PwrExt,
+        rcc::{self, RccExt},
+        stm32::Peripherals,
+    };
+
+    info!("start");
+
+    let dp = Peripherals::take().unwrap();
+
+    // Set system frequency to 16MHz * 15/1/2 = 120MHz
+    // This would lead to HrTim running at 120MHz * 32 = 3.84...
+    info!("rcc");
+    let pwr = dp.PWR.constrain().freeze();
+    let mut rcc = dp.RCC.freeze(
+        rcc::Config::pll().pll_cfg(rcc::PllConfig {
+            mux: rcc::PLLSrc::HSI,
+            n: rcc::PllNMul::MUL_15,
+            m: rcc::PllMDiv::DIV_1,
+            r: Some(rcc::PllRDiv::DIV_2),
+
+            ..Default::default()
+        }),
+        pwr,
+    );
+
+    info!("Setup Gpio");
+    let gpioa = dp.GPIOA.split(&mut rcc);
+    let gpiob = dp.GPIOB.split(&mut rcc);
+    let pin_a: PA8<Alternate<AF13>> = gpioa.pa8.into_alternate();
+
+    // ...with a prescaler of 4 this gives us a HrTimer with a tick rate of 960MHz
+    // With max the max period set, this would be 960MHz/2^16 ~= 15kHz...
+    let prescaler = Pscl4;
+
+    //        .               .
+    //        .  50%          .
+    //         ------          ------
+    //out1    |      |        |      |
+    //        |      |        |      |
+    // --------      ----------      --------
+    //        .    ^     ^
+    //        .    |     |
+    //AD samlp    pa0   temp
+    let period = 0xFFFF;
+    let (mut hr_control, _flt_inputs, eev_inputs) =
+        dp.HRTIM_COMMON.hr_control(&mut rcc).wait_for_calibration();
+
+    let eev_input3 = eev_inputs
+        .eev_input3
+        .bind(gpiob.pb7.into_pull_down_input())
+        .edge_or_polarity(external_event::EdgeOrPolarity::Polarity(
+            pwm::Polarity::ActiveHigh,
+        ))
+        .finalize(&mut hr_control);
+
+    let mut hr_control = hr_control.constrain();
+    let (mut timer, (mut cr1, _cr2, _cr3, _cr4), mut out1) = dp
+        .HRTIM_TIMA
+        .pwm_advanced(pin_a, &mut rcc)
+        .prescaler(prescaler)
+        .period(period)
+        .finalize(&mut hr_control);
+
+    out1.enable_rst_event(&cr1); // Set low on compare match with cr1
+    out1.enable_set_event(&timer); // Set high at new period
+
+    cr1.set_duty(period / 2);
+    timer.start(&mut hr_control);
+
+    let capture = timer.capture_ch1();
+    capture.enable_interrupt(true, &mut hr_control);
+    capture.add_event(&eev_input3);
+
+    loop {
+        if !capture.is_pending() {
+            continue;
+        }
+        capture.clear_interrupt();
+
+        info!("Capture: {:?}", capture.get());
+    }
+}