Merge #1330

1330: stm32/pwm: add complementary pwm r=Dirbaio a=xoviat

This implements complementary PWM with dead time on many supported targets. The specific dead-time programming functions are passed through directly to the user, which is a bit ugly but the best compromise I could reach for now.

Co-authored-by: xoviat <[email protected]>

1 files changed, 77 insertions, 0 deletions

diff --git a/examples/stm32f4/src/bin/pwm_complementary.rs b/examples/stm32f4/src/bin/pwm_complementary.rs
new file mode 100644
index 000000000..6e17f3fd3
--- /dev/null
+++ b/examples/stm32f4/src/bin/pwm_complementary.rs
@@ -0,0 +1,77 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+use defmt::*;
+use embassy_executor::Spawner;
+use embassy_stm32::pwm::complementary_pwm::{Ckd, ComplementaryPwm, ComplementaryPwmPin};
+use embassy_stm32::pwm::simple_pwm::PwmPin;
+use embassy_stm32::pwm::Channel;
+use embassy_stm32::time::khz;
+use embassy_time::{Duration, Timer};
+use {defmt_rtt as _, panic_probe as _};
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    let p = embassy_stm32::init(Default::default());
+    info!("Hello World!");
+
+    let ch1 = PwmPin::new_ch1(p.PE9);
+    let ch1n = ComplementaryPwmPin::new_ch1(p.PA7);
+    let mut pwm = ComplementaryPwm::new(
+        p.TIM1,
+        Some(ch1),
+        Some(ch1n),
+        None,
+        None,
+        None,
+        None,
+        None,
+        None,
+        khz(10),
+    );
+
+    /*
+        Dead-time = T_clk * T_dts * T_dtg
+
+        T_dts:
+        This bit-field indicates the division ratio between the timer clock (CK_INT) frequency and the
+        dead-time and sampling clock (tDTS)used by the dead-time generators and the digital filters
+        (ETR, TIx),
+        00: tDTS=tCK_INT
+        01: tDTS=2*tCK_INT
+        10: tDTS=4*tCK_INT
+
+        T_dtg:
+        This bit-field defines the duration of the dead-time inserted between the complementary
+        outputs. DT correspond to this duration.
+        DTG[7:5]=0xx => DT=DTG[7:0]x tdtg with tdtg=tDTS.
+        DTG[7:5]=10x => DT=(64+DTG[5:0])xtdtg with Tdtg=2xtDTS.
+        DTG[7:5]=110 => DT=(32+DTG[4:0])xtdtg with Tdtg=8xtDTS.
+        DTG[7:5]=111 => DT=(32+DTG[4:0])xtdtg with Tdtg=16xtDTS.
+        Example if TDTS=125ns (8MHz), dead-time possible values are:
+        0 to 15875 ns by 125 ns steps,
+        16 us to 31750 ns by 250 ns steps,
+        32 us to 63us by 1 us steps,
+        64 us to 126 us by 2 us steps
+    */
+    pwm.set_dead_time_clock_division(Ckd::DIV1);
+    pwm.set_dead_time_value(0);
+
+    let max = pwm.get_max_duty();
+    pwm.enable(Channel::Ch1);
+
+    info!("PWM initialized");
+    info!("PWM max duty {}", max);
+
+    loop {
+        pwm.set_duty(Channel::Ch1, 0);
+        Timer::after(Duration::from_millis(300)).await;
+        pwm.set_duty(Channel::Ch1, max / 4);
+        Timer::after(Duration::from_millis(300)).await;
+        pwm.set_duty(Channel::Ch1, max / 2);
+        Timer::after(Duration::from_millis(300)).await;
+        pwm.set_duty(Channel::Ch1, max - 1);
+        Timer::after(Duration::from_millis(300)).await;
+    }
+}