Merge #1333

1333: STM32: Adc V1 r=Dirbaio a=GrantM11235

Based on #947

Co-authored-by: Matthew W. Samsonoff <matt.samsonoff@gmail.com>
Co-authored-by: Grant Miller <GrantM11235@gmail.com>

embassy-stm32/src/adc/mod.rs

@@ -7,21 +7,18 @@
 #[cfg_attr(adc_v4, path = "v4.rs")]
 mod _version;
 
-#[cfg(not(any(adc_f1, adc_v1)))]
+#[cfg(not(adc_f1))]
 mod resolution;
-#[cfg(not(adc_v1))]
 mod sample_time;
 
 #[allow(unused)]
 pub use _version::*;
-#[cfg(not(any(adc_f1, adc_v1)))]
+#[cfg(not(adc_f1))]
 pub use resolution::Resolution;
-#[cfg(not(adc_v1))]
 pub use sample_time::SampleTime;
 
 use crate::peripherals;
 
-#[cfg(not(adc_v1))]
 pub struct Adc<'d, T: Instance> {
     #[allow(unused)]
     adc: crate::PeripheralRef<'d, T>,
@@ -44,9 +41,9 @@ pub(crate) mod sealed {
     }
 }
 
-#[cfg(not(any(adc_f1, adc_v2, adc_v4)))]
+#[cfg(not(any(adc_f1, adc_v1, adc_v2, adc_v4)))]
 pub trait Instance: sealed::Instance + crate::Peripheral<P = Self> {}
-#[cfg(any(adc_f1, adc_v2, adc_v4))]
+#[cfg(any(adc_f1, adc_v1, adc_v2, adc_v4))]
 pub trait Instance: sealed::Instance + crate::Peripheral<P = Self> + crate::rcc::RccPeripheral {}
 
 pub trait AdcPin<T: Instance>: sealed::AdcPin<T> {}

embassy-stm32/src/adc/resolution.rs

@@ -1,4 +1,4 @@
-#[cfg(any(adc_v2, adc_v3, adc_g0))]
+#[cfg(any(adc_v1, adc_v2, adc_v3, adc_g0))]
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
 pub enum Resolution {
     TwelveBit,
@@ -19,7 +19,7 @@ pub enum Resolution {
 
 impl Default for Resolution {
     fn default() -> Self {
-        #[cfg(any(adc_v2, adc_v3, adc_g0))]
+        #[cfg(any(adc_v1, adc_v2, adc_v3, adc_g0))]
         {
             Self::TwelveBit
         }
@@ -40,7 +40,7 @@ impl From<Resolution> for crate::pac::adc::vals::Res {
             Resolution::TwelveBit => crate::pac::adc::vals::Res::TWELVEBIT,
             Resolution::TenBit => crate::pac::adc::vals::Res::TENBIT,
             Resolution::EightBit => crate::pac::adc::vals::Res::EIGHTBIT,
-            #[cfg(any(adc_v2, adc_v3, adc_g0))]
+            #[cfg(any(adc_v1, adc_v2, adc_v3, adc_g0))]
             Resolution::SixBit => crate::pac::adc::vals::Res::SIXBIT,
         }
     }
@@ -56,7 +56,7 @@ impl Resolution {
             Resolution::TwelveBit => (1 << 12) - 1,
             Resolution::TenBit => (1 << 10) - 1,
             Resolution::EightBit => (1 << 8) - 1,
-            #[cfg(any(adc_v2, adc_v3, adc_g0))]
+            #[cfg(any(adc_v1, adc_v2, adc_v3, adc_g0))]
             Resolution::SixBit => (1 << 6) - 1,
         }
     }

embassy-stm32/src/adc/sample_time.rs

@@ -25,7 +25,7 @@ macro_rules! impl_sample_time {
     };
 }
 
-#[cfg(adc_f1)]
+#[cfg(any(adc_f1, adc_v1))]
 impl_sample_time!(
     "1.5",
     Cycles1_5,

embassy-stm32/src/adc/v1.rs

@@ -1 +1,171 @@
+use embassy_hal_common::into_ref;
+use embedded_hal_02::blocking::delay::DelayUs;
 
+use crate::adc::{Adc, AdcPin, Instance, InternalChannel, Resolution, SampleTime};
+use crate::peripherals::ADC;
+use crate::Peripheral;
+
+pub const VDDA_CALIB_MV: u32 = 3300;
+pub const VREF_INT: u32 = 1230;
+
+pub struct Vbat;
+impl InternalChannel<ADC> for Vbat {}
+impl super::sealed::InternalChannel<ADC> for Vbat {
+    fn channel(&self) -> u8 {
+        18
+    }
+}
+
+pub struct Vref;
+impl InternalChannel<ADC> for Vref {}
+impl super::sealed::InternalChannel<ADC> for Vref {
+    fn channel(&self) -> u8 {
+        17
+    }
+}
+
+pub struct Temperature;
+impl InternalChannel<ADC> for Temperature {}
+impl super::sealed::InternalChannel<ADC> for Temperature {
+    fn channel(&self) -> u8 {
+        16
+    }
+}
+
+impl<'d, T: Instance> Adc<'d, T> {
+    pub fn new(adc: impl Peripheral<P = T> + 'd, delay: &mut impl DelayUs<u32>) -> Self {
+        into_ref!(adc);
+        T::enable();
+        T::reset();
+
+        // Delay 1μs when using HSI14 as the ADC clock.
+        //
+        // Table 57. ADC characteristics
+        // tstab = 14 * 1/fadc
+        delay.delay_us(1);
+
+        let s = Self {
+            adc,
+            sample_time: Default::default(),
+        };
+        s.calibrate();
+        s
+    }
+
+    pub fn enable_vbat(&self, _delay: &mut impl DelayUs<u32>) -> Vbat {
+        // SMP must be ≥ 56 ADC clock cycles when using HSI14.
+        //
+        // 6.3.20 Vbat monitoring characteristics
+        // ts_vbat ≥ 4μs
+        unsafe {
+            T::regs().ccr().modify(|reg| reg.set_vbaten(true));
+        }
+        Vbat
+    }
+
+    pub fn enable_vref(&self, delay: &mut impl DelayUs<u32>) -> Vref {
+        // Table 28. Embedded internal reference voltage
+        // tstart = 10μs
+        unsafe {
+            T::regs().ccr().modify(|reg| reg.set_vrefen(true));
+        }
+        delay.delay_us(10);
+        Vref
+    }
+
+    pub fn enable_temperature(&self, delay: &mut impl DelayUs<u32>) -> Temperature {
+        // SMP must be ≥ 56 ADC clock cycles when using HSI14.
+        //
+        // 6.3.19 Temperature sensor characteristics
+        // tstart ≤ 10μs
+        // ts_temp ≥ 4μs
+        unsafe {
+            T::regs().ccr().modify(|reg| reg.set_tsen(true));
+        }
+        delay.delay_us(10);
+        Temperature
+    }
+
+    fn calibrate(&self) {
+        unsafe {
+            // A.7.1 ADC calibration code example
+            if T::regs().cr().read().aden() {
+                T::regs().cr().modify(|reg| reg.set_addis(true));
+            }
+            while T::regs().cr().read().aden() {
+                // spin
+            }
+            T::regs().cfgr1().modify(|reg| reg.set_dmaen(false));
+            T::regs().cr().modify(|reg| reg.set_adcal(true));
+            while T::regs().cr().read().adcal() {
+                // spin
+            }
+        }
+    }
+
+    pub fn set_sample_time(&mut self, sample_time: SampleTime) {
+        self.sample_time = sample_time;
+    }
+
+    pub fn set_resolution(&mut self, resolution: Resolution) {
+        unsafe {
+            T::regs().cfgr1().modify(|reg| reg.set_res(resolution.into()));
+        }
+    }
+
+    pub fn read<P>(&mut self, pin: &mut P) -> u16
+    where
+        P: AdcPin<T> + crate::gpio::sealed::Pin,
+    {
+        let channel = pin.channel();
+        unsafe {
+            pin.set_as_analog();
+            self.read_channel(channel)
+        }
+    }
+
+    pub fn read_internal(&mut self, channel: &mut impl InternalChannel<T>) -> u16 {
+        let channel = channel.channel();
+        unsafe { self.read_channel(channel) }
+    }
+
+    unsafe fn read_channel(&mut self, channel: u8) -> u16 {
+        // A.7.2 ADC enable sequence code example
+        if T::regs().isr().read().adrdy() {
+            T::regs().isr().modify(|reg| reg.set_adrdy(true));
+        }
+        T::regs().cr().modify(|reg| reg.set_aden(true));
+        while !T::regs().isr().read().adrdy() {
+            // ES0233, 2.4.3 ADEN bit cannot be set immediately after the ADC calibration
+            // Workaround: When the ADC calibration is complete (ADCAL = 0), keep setting the
+            // ADEN bit until the ADRDY flag goes high.
+            T::regs().cr().modify(|reg| reg.set_aden(true));
+        }
+
+        T::regs().isr().modify(|reg| {
+            reg.set_eoc(true);
+            reg.set_eosmp(true);
+        });
+
+        // A.7.5 Single conversion sequence code example - Software trigger
+        T::regs().chselr().write(|reg| reg.set_chselx(channel as usize, true));
+        T::regs().smpr().modify(|reg| reg.set_smp(self.sample_time.into()));
+        T::regs().cr().modify(|reg| reg.set_adstart(true));
+        while !T::regs().isr().read().eoc() {
+            // spin
+        }
+        let value = T::regs().dr().read().0 as u16;
+
+        // A.7.3 ADC disable code example
+        T::regs().cr().modify(|reg| reg.set_adstp(true));
+        while T::regs().cr().read().adstp() {
+            // spin
+        }
+        T::regs().cr().modify(|reg| reg.set_addis(true));
+        while T::regs().cr().read().aden() {
+            // spin
+        }
+
+        value
+    }
+}

examples/stm32f0/src/bin/adc.rs

@@ -0,0 +1,35 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+use defmt::*;
+use embassy_executor::Spawner;
+use embassy_stm32::adc::{Adc, SampleTime};
+use embassy_time::{Delay, 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 mut adc = Adc::new(p.ADC, &mut Delay);
+    adc.set_sample_time(SampleTime::Cycles71_5);
+    let mut pin = p.PA1;
+
+    let mut vrefint = adc.enable_vref(&mut Delay);
+    let vrefint_sample = adc.read_internal(&mut vrefint);
+    let convert_to_millivolts = |sample| {
+        // From https://www.st.com/resource/en/datasheet/stm32f031c6.pdf
+        // 6.3.4 Embedded reference voltage
+        const VREFINT_MV: u32 = 1230; // mV
+
+        (u32::from(sample) * VREFINT_MV / u32::from(vrefint_sample)) as u16
+    };
+
+    loop {
+        let v = adc.read(&mut pin);
+        info!("--> {} - {} mV", v, convert_to_millivolts(v));
+        Timer::after(Duration::from_millis(100)).await;
+    }
+}