Add DACv1 example for F4

examples/stm32f1/Cargo.toml

@@ -20,7 +20,6 @@ panic-probe = { version = "0.3", features = ["print-defmt"] }
 futures = { version = "0.3.17", default-features = false, features = ["async-await"] }
 heapless = { version = "0.7.5", default-features = false }
 nb = "1.0.0"
-micromath = "2.0.0"
 
 [profile.dev]
 opt-level = "s"

examples/stm32f4/Cargo.toml

@@ -21,6 +21,7 @@ futures = { version = "0.3.17", default-features = false, features = ["async-awa
 heapless = { version = "0.7.5", default-features = false }
 nb = "1.0.0"
 embedded-storage = "0.3.0"
+micromath = "2.0.0"
 
 usb-device = "0.2"
 usbd-serial = "0.1.1"

examples/stm32f4/src/bin/dac.rs

@@ -0,0 +1,37 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+use defmt::*;
+use embassy_executor::executor::Spawner;
+use embassy_stm32::dac::{Channel, Dac, Value};
+use embassy_stm32::Peripherals;
+use {defmt_rtt as _, panic_probe as _};
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner, p: Peripherals) -> ! {
+    info!("Hello World, dude!");
+
+    let mut dac = Dac::new_1ch(p.DAC, p.PA4);
+
+    loop {
+        for v in 0..=255 {
+            unwrap!(dac.set(Channel::Ch1, Value::Bit8(to_sine_wave(v))));
+            unwrap!(dac.trigger(Channel::Ch1));
+        }
+    }
+}
+
+use micromath::F32Ext;
+
+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
+    }
+}