add dac-dma example for h7, remove memory.x

examples/stm32h7/Cargo.toml

@@ -6,7 +6,7 @@ license = "MIT OR Apache-2.0"
 
 [dependencies]
 # Change stm32h743bi to your chip name, if necessary.
-embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["nightly", "defmt", "stm32h743bi", "time-driver-any", "exti", "unstable-pac", "unstable-traits"] }
+embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["nightly", "defmt", "stm32h743bi", "time-driver-any", "exti", "memory-x", "unstable-pac", "unstable-traits"] }
 embassy-sync = { version = "0.2.0", path = "../../embassy-sync", features = ["defmt"] }
 embassy-executor = { version = "0.2.0", path = "../../embassy-executor", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
 embassy-time = { version = "0.1.2", path = "../../embassy-time", features = ["defmt", "defmt-timestamp-uptime", "unstable-traits", "tick-hz-32_768"] }

examples/stm32h7/memory.x

@@ -1,5 +0,0 @@
-MEMORY
-{
-    FLASH : ORIGIN = 0x8000000, LENGTH = 1024K
-    RAM : ORIGIN = 0x24000000, LENGTH = 384K
-}

examples/stm32h7/src/bin/dac_dma.rs

@@ -0,0 +1,140 @@
+#![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::{mhz, Hertz};
+use embassy_stm32::timer::low_level::Basic16bitInstance;
+use micromath::F32Ext;
+use {defmt_rtt as _, panic_probe as _};
+
+pub type Dac1Type =
+    embassy_stm32::dac::DacCh1<'static, embassy_stm32::peripherals::DAC1, embassy_stm32::peripherals::DMA1_CH3>;
+
+pub type Dac2Type =
+    embassy_stm32::dac::DacCh2<'static, embassy_stm32::peripherals::DAC1, embassy_stm32::peripherals::DMA1_CH4>;
+
+#[embassy_executor::main]
+async fn main(spawner: Spawner) {
+    let mut config = embassy_stm32::Config::default();
+    config.rcc.sys_ck = Some(mhz(400));
+    config.rcc.hclk = Some(mhz(100));
+    config.rcc.pll1.q_ck = Some(mhz(100));
+
+    // 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();
+
+    spawner.spawn(dac_task1(dac_ch1)).ok();
+    spawner.spawn(dac_task2(dac_ch2)).ok();
+}
+
+#[embassy_executor::task]
+async fn dac_task1(mut dac: Dac1Type) {
+    let data: &[u8; 256] = &calculate_array::<256>();
+
+    info!("TIM6 frequency is {}", TIM6::frequency());
+    const FREQUENCY: Hertz = Hertz::hz(200);
+
+    // Compute the reload value such that we obtain the FREQUENCY for the sine
+    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(mut dac: Dac2Type) {
+    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
+}