feat: add Temperature struct to avoid enforcing usage of floats

- Also add misc derives to multiple structs
- Add power_up / power_down methods to TemperatureSensor
- Enable ApbSarAdc via PeripheralGuard

esp-hal/src/tsens.rs

@@ -31,10 +31,10 @@
 //!         Config::default()
 //!     ).unwrap();
 //! let delay = Delay::new();
-//!
+//! delay.delay_micros(200);
 //! loop {
-//!   let temp = temperature_sensor.get_celsius();
-//!   println!("Temperature: {:.2}°C", temp);
+//!   let temp = temperature_sensor.get_temperature();
+//!   println!("Temperature: {:.2}°C", temp.to_celcius());
 //!   delay.delay_millis(1_000);
 //! }
 //! # }
@@ -48,11 +48,11 @@
 use crate::{
     peripheral::{Peripheral, PeripheralRef},
     peripherals::TSENS,
-    system::{GenericPeripheralGuard, PeripheralClockControl},
+    system::GenericPeripheralGuard,
 };
 
 /// Clock source for the temperature sensor
-#[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
+#[derive(Debug, Clone, Default, PartialEq, Eq, Copy, Hash)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum ClockSource {
     /// Use RC_FAST clock source
@@ -63,48 +63,104 @@ pub enum ClockSource {
 }
 
 /// Temperature sensor configuration
-#[derive(Debug, Clone, Default, PartialEq, Eq, Copy, procmacros::BuilderLite)]
+#[derive(Debug, Clone, Default, PartialEq, Eq, Copy, Hash, procmacros::BuilderLite)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
+#[non_exhaustive]
 pub struct Config {
     clock_source: ClockSource,
 }
 
 /// Temperature sensor configuration error
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Copy, Hash)]
+#[non_exhaustive]
 pub enum ConfigError {}
 
+/// Temperature value
+/// This struct stores the raw ADC value, and can be used to calculate the
+/// temperature in Celsius using the formula:
+/// `(raw_value * 0.4386) - (offset * 27.88) - 20.52`
+#[derive(Debug)]
+pub struct Temperature {
+    /// Raw ADC value
+    pub raw_value: u8,
+
+    /// Offset value - depends on the temperature range configured
+    pub offset: i8,
+}
+
+impl Temperature {
+    /// Create a new temperature value
+    #[inline]
+    pub fn new(raw_value: u8, offset: i8) -> Self {
+        Self { raw_value, offset }
+    }
+
+    /// Get the temperature in Celsius
+    #[inline]
+    pub fn to_celsius(&self) -> f32 {
+        (self.raw_value as f32) * 0.4386 - (self.offset as f32) * 27.88 - 20.52
+    }
+
+    /// Get the temperature in Fahrenheit
+    #[inline]
+    pub fn to_fahrenheit(&self) -> f32 {
+        let celsius = self.to_celsius();
+        (celsius * 1.8) + 32.0
+    }
+
+    /// Get the temperature in Kelvin
+    #[inline]
+    pub fn to_kelvin(&self) -> f32 {
+        let celsius = self.to_celsius();
+        celsius + 273.15
+    }
+}
+
 /// Temperature sensor driver
+#[derive(Debug)]
 pub struct TemperatureSensor<'d> {
     _peripheral: PeripheralRef<'d, TSENS>,
-    _guard: GenericPeripheralGuard<{ crate::system::Peripheral::Tsens as u8 }>,
+    _tsens_guard: GenericPeripheralGuard<{ crate::system::Peripheral::Tsens as u8 }>,
+    _abp_saradc_guard: GenericPeripheralGuard<{ crate::system::Peripheral::ApbSarAdc as u8 }>,
 }
 
 impl<'d> TemperatureSensor<'d> {
     /// Create a new temperature sensor instance with configuration
+    /// The sensor will be automatically powered up
     pub fn new(
         peripheral: impl Peripheral<P = TSENS> + 'd,
         config: Config,
     ) -> Result<Self, ConfigError> {
         crate::into_ref!(peripheral);
-        let guard = GenericPeripheralGuard::new();
-
-        // We need to enable ApbSarAdc clock before trying to write on the tsens_ctrl
-        // register
-        PeripheralClockControl::enable(crate::system::Peripheral::ApbSarAdc);
-        let apb_saradc = unsafe { &*crate::peripherals::APB_SARADC::PTR };
-
-        // Power Up
-        apb_saradc.tsens_ctrl().write(|w| w.pu().set_bit());
+        // NOTE: We need enable ApbSarAdc before enabling Tsens
+        let apb_saradc_guard = GenericPeripheralGuard::new();
+        let tsens_guard = GenericPeripheralGuard::new();
 
         let mut tsens = Self {
-            _guard: guard,
             _peripheral: peripheral,
+            _tsens_guard: tsens_guard,
+            _abp_saradc_guard: apb_saradc_guard,
         };
         tsens.apply_config(&config)?;
 
+        tsens.power_up();
+
         Ok(tsens)
     }
 
+    /// Power up the temperature sensor
+    pub fn power_up(&self) {
+        debug!("Power up");
+        let abp_saradc = unsafe { &*crate::peripherals::APB_SARADC::PTR };
+        abp_saradc.tsens_ctrl().modify(|_, w| w.pu().set_bit());
+    }
+
+    /// Power down the temperature sensor - useful if you want to save power
+    pub fn power_down(&self) {
+        let abp_saradc = unsafe { &*crate::peripherals::APB_SARADC::PTR };
+        abp_saradc.tsens_ctrl().modify(|_, w| w.pu().clear_bit());
+    }
+
     /// Change the temperature sensor configuration
     pub fn apply_config(&mut self, config: &Config) -> Result<(), ConfigError> {
         let apb_saradc = unsafe { &*crate::peripherals::APB_SARADC::PTR };
@@ -118,29 +174,16 @@ impl<'d> TemperatureSensor<'d> {
         Ok(())
     }
 
-    /// Get the temperature in Celsius
+    /// Get the raw temperature value
     #[inline]
-    pub fn get_celsius(&self) -> f32 {
+    pub fn get_temperature(&self) -> Temperature {
         let abp_saradc = unsafe { &*crate::peripherals::APB_SARADC::PTR };
 
-        let measurement = abp_saradc.tsens_ctrl().read().out().bits();
+        let raw_value = abp_saradc.tsens_ctrl().read().out().bits();
 
         // TODO Address multiple temperature ranges and offsets
-        let offset = -1f32;
-        (measurement as f32) * 0.4386 - offset * 27.88 - 20.52
-    }
+        let offset = -1i8;
 
-    /// Get the temperature in Fahrenheit
-    #[inline]
-    pub fn get_fahrenheit(&self) -> f32 {
-        let celsius = self.get_celsius();
-        (celsius * 1.8) + 32.0
-    }
-
-    /// Get the temperature in Kelvin
-    #[inline]
-    pub fn get_kelvin(&self) -> f32 {
-        let celsius = self.get_celsius();
-        celsius + 273.15
+        Temperature::new(raw_value, offset)
     }
 }

qa-test/src/bin/temperature_sensor.rs

@@ -1,5 +1,5 @@
-//! This example uses the internal temperature sensor to measure the chip's temperature
-//!
+//! This example uses the internal temperature sensor to measure the chip's
+//! temperature
 
 //% CHIPS: esp32c6 esp32c3
 
@@ -26,8 +26,8 @@ fn main() -> ! {
     delay.delay_micros(200);
 
     loop {
-        let temp = temperature_sensor.get_celsius();
-        println!("Temperature: {:.2}°C", temp);
+        let temp = temperature_sensor.get_temperature();
+        println!("Temperature: {:.2}°C", temp.to_celsius());
         delay.delay_millis(1_000);
     }
 }