Add DAC HIL test with ADC

tests/stm32/Cargo.toml

@@ -7,11 +7,11 @@ autobins = false
 
 [features]
 stm32f103c8 = ["embassy-stm32/stm32f103c8", "not-gpdma"]     # Blue Pill
-stm32f429zi = ["embassy-stm32/stm32f429zi", "chrono", "can", "not-gpdma"]     # Nucleo "sdmmc"
+stm32f429zi = ["embassy-stm32/stm32f429zi", "chrono", "can", "not-gpdma", "dac-adc-pin"]     # Nucleo "sdmmc"
-stm32g071rb = ["embassy-stm32/stm32g071rb", "not-gpdma"]     # Nucleo
+stm32g071rb = ["embassy-stm32/stm32g071rb", "not-gpdma", "dac-adc-pin"]     # Nucleo
 stm32c031c6 = ["embassy-stm32/stm32c031c6", "not-gpdma"]     # Nucleo
 stm32g491re = ["embassy-stm32/stm32g491re", "not-gpdma"]     # Nucleo
-stm32h755zi = ["embassy-stm32/stm32h755zi-cm7", "not-gpdma"] # Nucleo
+stm32h755zi = ["embassy-stm32/stm32h755zi-cm7", "not-gpdma", "dac-adc-pin"] # Nucleo
 stm32wb55rg = ["embassy-stm32/stm32wb55rg", "not-gpdma", "ble", "mac" ]     # Nucleo
 stm32h563zi = ["embassy-stm32/stm32h563zi"]     # Nucleo
 stm32u585ai = ["embassy-stm32/stm32u585ai"]     # IoT board
@@ -23,6 +23,7 @@ ble = ["dep:embassy-stm32-wpan", "embassy-stm32-wpan/ble"]
 mac = ["dep:embassy-stm32-wpan", "embassy-stm32-wpan/mac"]
 embassy-stm32-wpan = []
 not-gpdma = []
+dac-adc-pin = []
 
 [dependencies]
 teleprobe-meta = "1"
@@ -42,6 +43,7 @@ cortex-m-rt = "0.7.0"
 embedded-hal = "0.2.6"
 embedded-hal-1 = { package = "embedded-hal", version = "=1.0.0-alpha.11" }
 embedded-hal-async = { version = "=0.2.0-alpha.2" }
+micromath = "2.0.0"
 panic-probe = { version = "0.3.0", features = ["print-defmt"] }
 rand_core = { version = "0.6", default-features = false }
 rand_chacha = { version = "0.3", default-features = false }
@@ -55,6 +57,11 @@ name = "can"
 path = "src/bin/can.rs"
 required-features = [ "can",]
 
+[[bin]]
+name = "dac"
+path = "src/bin/dac.rs"
+required-features = [ "dac-adc-pin",]
+
 [[bin]]
 name = "gpio"
 path = "src/bin/gpio.rs"

tests/stm32/src/bin/dac.rs

@@ -0,0 +1,81 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+// required-features: dac-adc-pin
+
+#[path = "../common.rs"]
+mod common;
+use common::*;
+use defmt::assert;
+use embassy_executor::Spawner;
+use embassy_stm32::adc::Adc;
+use embassy_stm32::dac::{DacCh1, DacChannel, Value};
+use embassy_stm32::dma::NoDma;
+use embassy_time::{Delay, Duration, Timer};
+use {defmt_rtt as _, panic_probe as _};
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    // Initialize the board and obtain a Peripherals instance
+    let p: embassy_stm32::Peripherals = embassy_stm32::init(config());
+
+    #[cfg(feature = "stm32f429zi")]
+    let dac_peripheral = p.DAC;
+
+    #[cfg(any(feature = "stm32h755zi", feature = "stm32g071rb"))]
+    let dac_peripheral = p.DAC1;
+
+    let mut dac: DacCh1<'_, _, NoDma> = DacCh1::new(dac_peripheral, NoDma, p.PA4);
+    unwrap!(dac.set_trigger_enable(false));
+
+    let mut adc = Adc::new(p.ADC1, &mut Delay);
+
+    #[cfg(feature = "stm32h755zi")]
+    let normalization_factor = 256;
+    #[cfg(any(feature = "stm32f429zi", feature = "stm32g071rb"))]
+    let normalization_factor: i32 = 16;
+
+    unwrap!(dac.set(Value::Bit8(0)));
+    // Now wait a little to obtain a stable value
+    Timer::after(Duration::from_millis(30)).await;
+    let offset = adc.read(&mut unsafe { embassy_stm32::Peripherals::steal() }.PA4);
+
+    for v in 0..=255 {
+        // First set the DAC output value
+        let dac_output_val = to_sine_wave(v);
+        unwrap!(dac.set(Value::Bit8(dac_output_val)));
+
+        // Now wait a little to obtain a stable value
+        Timer::after(Duration::from_millis(30)).await;
+
+        // Need to steal the peripherals here because PA4 is obviously in use already
+        let measured = adc.read(&mut unsafe { embassy_stm32::Peripherals::steal() }.PA4);
+        // Calibrate and normalize the measurement to get close to the dac_output_val
+        let measured_normalized = ((measured as i32 - offset as i32) / normalization_factor) as i16;
+
+        info!("value / measured: {} / {}", dac_output_val, measured_normalized);
+
+        // The deviations are quite enormous but that does not matter since this is only a quick test
+        assert!((dac_output_val as i16 - measured_normalized).abs() < 15);
+    }
+
+    info!("Test OK");
+    cortex_m::asm::bkpt();
+}
+
+use core::f32::consts::PI;
+
+use micromath::F32Ext;
+
+fn to_sine_wave(v: u8) -> u8 {
+    if v >= 128 {
+        // top half
+        let r = PI * ((v - 128) as f32 / 128.0);
+        (r.sin() * 128.0 + 127.0) as u8
+    } else {
+        // bottom half
+        let r = PI + PI * (v as f32 / 128.0);
+        (r.sin() * 128.0 + 127.0) as u8
+    }
+}

tests/stm32/src/common.rs

@@ -33,6 +33,7 @@ pub fn config() -> Config {
     {
         config.rcc.sys_ck = Some(Hertz(400_000_000));
         config.rcc.pll1.q_ck = Some(Hertz(100_000_000));
+        config.rcc.adc_clock_source = embassy_stm32::rcc::AdcClockSource::PerCk;
     }
 
     #[cfg(feature = "stm32u585ai")]