feat(http-example): expose the internal temp sensor as a JSON endpoint

examples/embassy-http-server/Cargo.toml

@@ -11,6 +11,7 @@ embassy-net = { workspace = true, features = ["tcp"] }
 embassy-sync = { workspace = true }
 embassy-time = { workspace = true, default-features = false }
 embedded-io-async = "0.6.0"
+fixed = "1.24.0"
 heapless = { workspace = true }
 httparse = { version = "1.8.0", default-features = false }
 picoserve = { version = "0.8.0", default-features = false, features = ["embassy"] }
@@ -23,3 +24,4 @@ embassy-nrf = { workspace = true, optional = true }
 
 [features]
 button-readings = ["dep:embassy-nrf"]
+internal-temp = ["riot-rs/internal-temp"]

examples/embassy-http-server/laze.yml

@@ -8,6 +8,7 @@ apps:
       - ?release
       - network
       - ?button-readings
+      - ?internal-temp
 
 modules:
   - name: button-readings
@@ -17,3 +18,11 @@ modules:
       global:
         FEATURES:
           - button-readings
+
+  - name: internal-temp
+    context:
+      - nrf52840
+    env:
+      global:
+        FEATURES:
+          - internal-temp

examples/embassy-http-server/src/main.rs

@@ -8,7 +8,7 @@ mod routes;
 
 use riot_rs as _;
 
-use riot_rs::embassy::network;
+use riot_rs::embassy::{arch, network};
 use riot_rs::rt::debug::println;
 
 use embassy_net::tcp::TcpSocket;
@@ -23,6 +23,8 @@ use embassy_nrf::gpio::{Input, Pin, Pull};
 struct AppState {
     #[cfg(feature = "button-readings")]
     buttons: ButtonInputs,
+    #[cfg(context = "nrf52840")]
+    temp: TempInput,
 }
 
 #[cfg(feature = "button-readings")]
@@ -44,6 +46,17 @@ impl picoserve::extract::FromRef<AppState> for ButtonInputs {
     }
 }
 
+#[cfg(context = "nrf52840")]
+#[derive(Copy, Clone)]
+struct TempInput(&'static Mutex<CriticalSectionRawMutex, embassy_nrf::temp::Temp<'static>>);
+
+#[cfg(context = "nrf52840")]
+impl picoserve::extract::FromRef<AppState> for TempInput {
+    fn from_ref(state: &AppState) -> Self {
+        state.temp
+    }
+}
+
 type AppRouter = impl picoserve::routing::PathRouter<AppState>;
 
 const WEB_TASK_POOL_SIZE: usize = 2;
@@ -89,7 +102,7 @@ async fn web_task(
 use riot_rs::embassy::{arch::OptionalPeripherals, Spawner};
 #[riot_rs::embassy::distributed_slice(riot_rs::embassy::EMBASSY_TASKS)]
 #[linkme(crate = riot_rs::embassy::linkme)]
-fn web_server_init(spawner: &Spawner, peripherals: &mut OptionalPeripherals) {
+fn web_server_init(spawner: &Spawner, peripherals: &mut arch::OptionalPeripherals) {
     #[cfg(feature = "button-readings")]
     let button_inputs = {
         let buttons = pins::Buttons::take_from(peripherals).unwrap();
@@ -104,10 +117,18 @@ fn web_server_init(spawner: &Spawner, peripherals: &mut OptionalPeripherals) {
         ButtonInputs(make_static!(Mutex::new(buttons)))
     };
 
+    #[cfg(context = "nrf52840")]
+    let temp = {
+        let temp = arch::internal_temp::sensor(peripherals.TEMP.take().unwrap());
+        TempInput(make_static!(Mutex::new(temp)))
+    };
+
     fn make_app() -> picoserve::Router<AppRouter, AppState> {
         let router = picoserve::Router::new().route("/", get(routes::index));
         #[cfg(feature = "button-readings")]
         let router = router.route("/buttons", get(routes::buttons));
+        #[cfg(context = "nrf52840")]
+        let router = router.route("/api/temp", get(routes::temp));
         router
     }
 
@@ -123,6 +144,8 @@ fn web_server_init(spawner: &Spawner, peripherals: &mut OptionalPeripherals) {
         let app_state = AppState {
             #[cfg(feature = "button-readings")]
             buttons: button_inputs,
+            #[cfg(context = "nrf52840")]
+            temp,
         };
         spawner.spawn(web_task(id, app, config, app_state)).unwrap();
     }

examples/embassy-http-server/src/pins.rs

@@ -10,3 +10,6 @@ define_peripherals!(Buttons {
     btn3: P0_24,
     btn4: P0_25,
 });
+
+#[cfg(context = "nrf52840")]
+define_peripherals!(Temp { temp: TEMP });

examples/embassy-http-server/src/routes/mod.rs

@@ -3,7 +3,13 @@ pub mod index;
 #[cfg(feature = "button-readings")]
 pub mod buttons;
 
+#[cfg(context = "nrf52840")]
+pub mod temp;
+
 pub use index::index;
 
 #[cfg(feature = "button-readings")]
 pub use buttons::buttons;
+
+#[cfg(context = "nrf52840")]
+pub use temp::temp;

examples/embassy-http-server/src/routes/temp.rs

@@ -0,0 +1,19 @@
+use fixed::traits::LossyInto;
+use picoserve::{
+    extract::State,
+    response::{IntoResponse, Json},
+};
+
+use crate::TempInput;
+
+pub async fn temp(State(TempInput(temp)): State<TempInput>) -> impl IntoResponse {
+    let temp = (100 * temp.lock().await.read().await).lossy_into();
+
+    Json(JsonTemp { temp })
+}
+
+#[derive(serde::Serialize)]
+struct JsonTemp {
+    // Temperature in hundredths of degrees Celsius
+    temp: i32,
+}

src/riot-rs-embassy/Cargo.toml

@@ -66,6 +66,7 @@ time = ["dep:embassy-time", "embassy-executor/integrated-timers"]
 usb = ["dep:embassy-usb"]
 net = ["dep:embassy-net"]
 usb-ethernet = ["usb", "net"]
+internal-temp = []
 
 wifi-cyw43 = ["dep:cyw43", "dep:cyw43-pio", "dep:embassy-net-driver-channel", "net"]
 

src/riot-rs-embassy/src/arch/nrf52.rs

@@ -38,3 +38,16 @@ pub fn init(config: Config) -> OptionalPeripherals {
     let peripherals = embassy_nrf::init(config);
     OptionalPeripherals::from(peripherals)
 }
+
+#[cfg(feature = "internal-temp")]
+pub mod internal_temp {
+    use embassy_nrf::{peripherals, temp};
+
+    embassy_nrf::bind_interrupts!(struct TempIrqs {
+        TEMP => embassy_nrf::temp::InterruptHandler;
+    });
+
+    pub fn sensor(temp: peripherals::TEMP) -> temp::Temp<'static> {
+        temp::Temp::new(temp, TempIrqs)
+    }
+}

src/riot-rs/Cargo.toml

@@ -21,6 +21,7 @@ static_cell = { workspace = true }
 default = ["riot-rs-rt/_panic-handler"]
 
 debug-console = ["riot-rs-rt/debug-console"]
+internal-temp = ["riot-rs-embassy/internal-temp"]
 net = ["riot-rs-embassy/net"]
 # Allows to have no boards selected, useful to run platform-independent tooling
 no-boards = ["riot-rs-boards/no-boards"]