Update DAC examples, add DAC + DMA example

embassy-stm32/src/dac/mod.rs

@@ -178,7 +178,7 @@ pub trait DacChannel<T: Instance, Tx> {
 ///
 /// # Example for obtaining both DAC channels
 ///
-/// ```no_run
+/// ```ignore
 /// // DMA channels and pins may need to be changed for your controller
 /// let (dac_ch1, dac_ch2) =
 ///     embassy_stm32::dac::Dac::new(p.DAC1, p.DMA1_CH3, p.DMA1_CH4, p.PA4, p.PA5).split();

examples/stm32f4/src/bin/dac.rs

@@ -4,7 +4,8 @@
 
 use defmt::*;
 use embassy_executor::Spawner;
-use embassy_stm32::dac::{Channel, Dac, Value};
+use embassy_stm32::dac::{DacCh1, DacChannel, Value};
+use embassy_stm32::dma::NoDma;
 use {defmt_rtt as _, panic_probe as _};
 
 #[embassy_executor::main]
@@ -12,12 +13,12 @@ async fn main(_spawner: Spawner) -> ! {
     let p = embassy_stm32::init(Default::default());
     info!("Hello World, dude!");
 
-    let mut dac = Dac::new_1ch(p.DAC, p.PA4);
+    let mut dac = DacCh1::new(p.DAC, NoDma, p.PA4);
 
     loop {
         for v in 0..=255 {
-            unwrap!(dac.set(Channel::Ch1, Value::Bit8(to_sine_wave(v))));
+            unwrap!(dac.set(Value::Bit8(to_sine_wave(v))));
-            unwrap!(dac.trigger(Channel::Ch1));
+            dac.trigger();
         }
     }
 }

examples/stm32h7/src/bin/dac.rs

@@ -4,7 +4,8 @@
 
 use cortex_m_rt::entry;
 use defmt::*;
-use embassy_stm32::dac::{Channel, Dac, Value};
+use embassy_stm32::dac::{DacCh1, DacChannel, Value};
+use embassy_stm32::dma::NoDma;
 use embassy_stm32::time::mhz;
 use embassy_stm32::Config;
 use {defmt_rtt as _, panic_probe as _};
@@ -19,12 +20,12 @@ fn main() -> ! {
     config.rcc.pll1.q_ck = Some(mhz(100));
     let p = embassy_stm32::init(config);
 
-    let mut dac = Dac::new_1ch(p.DAC1, p.PA4);
+    let mut dac = DacCh1::new(p.DAC1, NoDma, p.PA4);
 
     loop {
         for v in 0..=255 {
-            unwrap!(dac.set(Channel::Ch1, Value::Bit8(to_sine_wave(v))));
+            unwrap!(dac.set(Value::Bit8(to_sine_wave(v))));
-            unwrap!(dac.trigger(Channel::Ch1));
+            dac.trigger();
         }
     }
 }

examples/stm32l4/Cargo.toml

@@ -25,3 +25,5 @@ futures = { version = "0.3.17", default-features = false, features = ["async-awa
 heapless = { version = "0.7.5", default-features = false }
 
 micromath = "2.0.0"
+
+static_cell = "1.0.0"

examples/stm32l4/src/bin/dac.rs

@@ -3,26 +3,22 @@
 #![feature(type_alias_impl_trait)]
 
 use defmt::*;
-use embassy_stm32::dac::{Channel, Dac, Value};
+use embassy_stm32::dac::{DacCh1, DacChannel, Value};
+use embassy_stm32::dma::NoDma;
 use embassy_stm32::pac;
 use {defmt_rtt as _, panic_probe as _};
 
 #[cortex_m_rt::entry]
 fn main() -> ! {
+    let p = embassy_stm32::init(Default::default());
     info!("Hello World!");
 
-    pac::RCC.apb1enr1().modify(|w| {
+    let mut dac = DacCh1::new(p.DAC1, NoDma, p.PA4);
-        w.set_dac1en(true);
-    });
-
-    let p = embassy_stm32::init(Default::default());
-
-    let mut dac = Dac::new_1ch(p.DAC1, p.PA4);
 
     loop {
         for v in 0..=255 {
-            unwrap!(dac.set(Channel::Ch1, Value::Bit8(to_sine_wave(v))));
+            unwrap!(dac.set(Value::Bit8(to_sine_wave(v))));
-            unwrap!(dac.trigger(Channel::Ch1));
+            dac.trigger();
         }
     }
 }

examples/stm32l4/src/bin/dac_dma.rs

@@ -0,0 +1,148 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+use defmt::*;
+use embassy_executor::Spawner;
+use embassy_stm32::dac::{DacChannel, ValueArray};
+use embassy_stm32::pac::timer::vals::{Mms, Opm};
+use embassy_stm32::peripherals::{TIM6, TIM7};
+use embassy_stm32::rcc::low_level::RccPeripheral;
+use embassy_stm32::time::Hertz;
+use embassy_stm32::timer::low_level::Basic16bitInstance;
+use micromath::F32Ext;
+use static_cell::StaticCell;
+use {defmt_rtt as _, panic_probe as _};
+
+pub type Dac1Type<'d> =
+    embassy_stm32::dac::DacCh1<'d, embassy_stm32::peripherals::DAC1, embassy_stm32::peripherals::DMA1_CH3>;
+
+pub type Dac2Type<'d> =
+    embassy_stm32::dac::DacCh2<'d, embassy_stm32::peripherals::DAC1, embassy_stm32::peripherals::DMA1_CH4>;
+
+#[embassy_executor::main]
+async fn main(spawner: Spawner) {
+    let config = embassy_stm32::Config::default();
+
+    // Initialize the board and obtain a Peripherals instance
+    let p: embassy_stm32::Peripherals = embassy_stm32::init(config);
+
+    // Obtain two independent channels (p.DAC1 can only be consumed once, though!)
+    let (dac_ch1, dac_ch2) = embassy_stm32::dac::Dac::new(p.DAC1, p.DMA1_CH3, p.DMA1_CH4, p.PA4, p.PA5).split();
+
+    let dac1 = {
+        type T = impl Sized;
+        static STATIC_CELL: StaticCell<T> = StaticCell::new();
+        STATIC_CELL.init(dac_ch1)
+    };
+
+    let dac2 = {
+        type T = impl Sized;
+        static STATIC_CELL: StaticCell<T> = StaticCell::new();
+        STATIC_CELL.init(dac_ch2)
+    };
+
+    spawner.spawn(dac_task1(dac1)).ok();
+    spawner.spawn(dac_task2(dac2)).ok();
+}
+
+#[embassy_executor::task]
+async fn dac_task1(dac: &'static mut Dac1Type<'static>) {
+    let data: &[u8; 256] = &calculate_array::<256>();
+
+    info!("TIM6 frequency is {}", TIM6::frequency());
+    const FREQUENCY: Hertz = Hertz::hz(200);
+    let reload: u32 = (TIM6::frequency().0 / FREQUENCY.0) / data.len() as u32;
+
+    // Depends on your clock and on the specific chip used, you may need higher or lower values here
+    if reload < 10 {
+        error!("Reload value {} below threshold!", reload);
+    }
+
+    dac.select_trigger(embassy_stm32::dac::Ch1Trigger::Tim6).unwrap();
+    dac.enable_channel().unwrap();
+
+    TIM6::enable();
+    TIM6::regs().arr().modify(|w| w.set_arr(reload as u16 - 1));
+    TIM6::regs().cr2().modify(|w| w.set_mms(Mms::UPDATE));
+    TIM6::regs().cr1().modify(|w| {
+        w.set_opm(Opm::DISABLED);
+        w.set_cen(true);
+    });
+
+    debug!(
+        "TIM6 Frequency {}, Target Frequency {}, Reload {}, Reload as u16 {}, Samples {}",
+        TIM6::frequency(),
+        FREQUENCY,
+        reload,
+        reload as u16,
+        data.len()
+    );
+
+    // Loop technically not necessary if DMA circular mode is enabled
+    loop {
+        info!("Loop DAC1");
+        if let Err(e) = dac.write(ValueArray::Bit8(data), true).await {
+            error!("Could not write to dac: {}", e);
+        }
+    }
+}
+
+#[embassy_executor::task]
+async fn dac_task2(dac: &'static mut Dac2Type<'static>) {
+    let data: &[u8; 256] = &calculate_array::<256>();
+    
+    info!("TIM7 frequency is {}", TIM7::frequency());
+
+    const FREQUENCY: Hertz = Hertz::hz(600);
+    let reload: u32 = (TIM7::frequency().0 / FREQUENCY.0) / data.len() as u32;
+
+    if reload < 10 {
+        error!("Reload value {} below threshold!", reload);
+    }
+
+    TIM7::enable();
+    TIM7::regs().arr().modify(|w| w.set_arr(reload as u16 - 1));
+    TIM7::regs().cr2().modify(|w| w.set_mms(Mms::UPDATE));
+    TIM7::regs().cr1().modify(|w| {
+        w.set_opm(Opm::DISABLED);
+        w.set_cen(true);
+    });
+
+    dac.select_trigger(embassy_stm32::dac::Ch2Trigger::Tim7).unwrap();
+
+    debug!(
+        "TIM7 Frequency {}, Target Frequency {}, Reload {}, Reload as u16 {}, Samples {}",
+        TIM7::frequency(),
+        FREQUENCY,
+        reload,
+        reload as u16,
+        data.len()
+    );
+
+    if let Err(e) = dac.write(ValueArray::Bit8(data), true).await {
+        error!("Could not write to dac: {}", e);
+    }
+}
+
+fn to_sine_wave(v: u8) -> u8 {
+    if v >= 128 {
+        // top half
+        let r = 3.14 * ((v - 128) as f32 / 128.0);
+        (r.sin() * 128.0 + 127.0) as u8
+    } else {
+        // bottom half
+        let r = 3.14 + 3.14 * (v as f32 / 128.0);
+        (r.sin() * 128.0 + 127.0) as u8
+    }
+}
+
+fn calculate_array<const N: usize>() -> [u8; N] {
+    let mut res = [0; N];
+    let mut i = 0;
+    while i < N {
+        res[i] = to_sine_wave(i as u8);
+        i += 1;
+    }
+    res
+}