Merge #436

436: Add support for temperature sensor peripheral r=lulf a=lulf

* Add TEMP peripheral to all nRF52 chips
* Add async HAL for reading temperature values
* Add example application reading temperature values

Co-authored-by: Ulf Lilleengen <lulf@redhat.com>
Co-authored-by: Ulf Lilleengen <ulf.lilleengen@gmail.com>

embassy-nrf/Cargo.toml

@@ -48,6 +48,7 @@ embedded-dma    = "0.1.2"
 futures     = { version = "0.3.17", default-features = false }
 critical-section = "0.2.3"
 rand_core = "0.6.3"
+fixed = "1.10.0"
 
 nrf52805-pac  = { version = "0.10.1", optional = true, features = [ "rt" ] }
 nrf52810-pac  = { version = "0.10.1", optional = true, features = [ "rt" ] }

embassy-nrf/src/chips/nrf52805.rs

@@ -114,6 +114,9 @@ embassy_hal_common::peripherals! {
     P0_29,
     P0_30,
     P0_31,
+
+    // TEMP
+    TEMP,
 }
 
 impl_uarte!(UARTE0, UARTE0, UARTE0_UART0);

embassy-nrf/src/chips/nrf52810.rs

@@ -117,6 +117,9 @@ embassy_hal_common::peripherals! {
     P0_29,
     P0_30,
     P0_31,
+
+    // TEMP
+    TEMP,
 }
 
 impl_uarte!(UARTE0, UARTE0, UARTE0_UART0);

embassy-nrf/src/chips/nrf52811.rs

@@ -117,6 +117,9 @@ embassy_hal_common::peripherals! {
     P0_29,
     P0_30,
     P0_31,
+
+    // TEMP
+    TEMP,
 }
 
 impl_uarte!(UARTE0, UARTE0, UARTE0_UART0);

embassy-nrf/src/chips/nrf52820.rs

@@ -112,6 +112,9 @@ embassy_hal_common::peripherals! {
     P0_29,
     P0_30,
     P0_31,
+
+    // TEMP
+    TEMP,
 }
 
 impl_uarte!(UARTE0, UARTE0, UARTE0_UART0);

embassy-nrf/src/chips/nrf52832.rs

@@ -124,6 +124,9 @@ embassy_hal_common::peripherals! {
     P0_29,
     P0_30,
     P0_31,
+
+    // TEMP
+    TEMP,
 }
 
 impl_uarte!(UARTE0, UARTE0, UARTE0_UART0);

embassy-nrf/src/chips/nrf52833.rs

@@ -144,6 +144,9 @@ embassy_hal_common::peripherals! {
     P1_13,
     P1_14,
     P1_15,
+
+    // TEMP
+    TEMP,
 }
 
 impl_uarte!(UARTE0, UARTE0, UARTE0_UART0);

embassy-nrf/src/chips/nrf52840.rs

@@ -147,6 +147,9 @@ embassy_hal_common::peripherals! {
     P1_13,
     P1_14,
     P1_15,
+
+    // TEMP
+    TEMP,
 }
 
 impl_uarte!(UARTE0, UARTE0, UARTE0_UART0);

embassy-nrf/src/lib.rs

@@ -39,6 +39,8 @@ pub mod rng;
 #[cfg(not(feature = "nrf52820"))]
 pub mod saadc;
 pub mod spim;
+#[cfg(not(feature = "nrf9160"))]
+pub mod temp;
 pub mod timer;
 pub mod twim;
 pub mod uarte;

embassy-nrf/src/temp.rs

@@ -0,0 +1,86 @@
+//! Temperature sensor interface.
+
+use crate::interrupt;
+use crate::pac;
+use crate::peripherals::TEMP;
+
+use core::marker::PhantomData;
+use core::task::Poll;
+use embassy::interrupt::InterruptExt;
+use embassy::util::Unborrow;
+use embassy::waitqueue::AtomicWaker;
+use embassy_hal_common::{drop::OnDrop, unborrow};
+use fixed::types::I30F2;
+use futures::future::poll_fn;
+
+/// Integrated temperature sensor.
+pub struct Temp<'d> {
+    _temp: PhantomData<&'d TEMP>,
+    _irq: interrupt::TEMP,
+}
+
+static WAKER: AtomicWaker = AtomicWaker::new();
+
+impl<'d> Temp<'d> {
+    pub fn new(
+        _t: impl Unborrow<Target = TEMP> + 'd,
+        irq: impl Unborrow<Target = interrupt::TEMP> + 'd,
+    ) -> Self {
+        unborrow!(_t, irq);
+
+        // Enable interrupt that signals temperature values
+        irq.disable();
+        irq.set_handler(|_| {
+            let t = Self::regs();
+            t.intenclr.write(|w| w.datardy().clear());
+            WAKER.wake();
+        });
+        irq.enable();
+        Self {
+            _temp: PhantomData,
+            _irq: irq,
+        }
+    }
+
+    /// Perform an asynchronous temperature measurement. The returned future
+    /// can be awaited to obtain the measurement.
+    ///
+    /// If the future is dropped, the measurement is cancelled.
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// let mut t = Temp::new(p.TEMP, interrupt::take!(TEMP));
+    /// let v: u16 = t.read().await.to_num::<u16>();
+    /// ```
+    pub async fn read(&mut self) -> I30F2 {
+        // In case the future is dropped, stop the task and reset events.
+        let on_drop = OnDrop::new(|| {
+            let t = Self::regs();
+            t.tasks_stop.write(|w| unsafe { w.bits(1) });
+            t.events_datardy.reset();
+        });
+
+        let t = Self::regs();
+        t.intenset.write(|w| w.datardy().set());
+        unsafe { t.tasks_start.write(|w| w.bits(1)) };
+
+        let value = poll_fn(|cx| {
+            WAKER.register(cx.waker());
+            if t.events_datardy.read().bits() == 0 {
+                return Poll::Pending;
+            } else {
+                t.events_datardy.reset();
+                let raw = t.temp.read().bits();
+                Poll::Ready(I30F2::from_bits(raw as i32))
+            }
+        })
+        .await;
+        on_drop.defuse();
+        value
+    }
+
+    fn regs() -> &'static pac::temp::RegisterBlock {
+        unsafe { &*pac::TEMP::ptr() }
+    }
+}

examples/nrf/src/bin/temp.rs

@@ -0,0 +1,26 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use example_common::*;
+
+use defmt::panic;
+use embassy::{
+    executor::Spawner,
+    time::{Duration, Timer},
+};
+use embassy_nrf::{interrupt, temp::Temp, Peripherals};
+
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    let irq = interrupt::take!(TEMP);
+    let mut temp = Temp::new(p.TEMP, irq);
+
+    loop {
+        let value = temp.read().await;
+        info!("temperature: {}℃", value.to_num::<u16>());
+        Timer::after(Duration::from_secs(1)).await;
+    }
+}