From 2bff0a54c73fb19d67b1a20892e88f404450ff37 Mon Sep 17 00:00:00 2001
From: Andreas Tsouchlos <an.tsouchlos@gmail.com>
Date: Sat, 4 Oct 2025 15:47:26 +0200
Subject: [PATCH] Refactor HumiditySensor to directly take Twim() as argument;
 Move measurement into separate task

---
 src/bin/temp_rh_measurement.rs | 108 +++++++++++----------------------
 1 file changed, 34 insertions(+), 74 deletions(-)

diff --git a/src/bin/temp_rh_measurement.rs b/src/bin/temp_rh_measurement.rs
index d6b119d..78272e6 100644
--- a/src/bin/temp_rh_measurement.rs
+++ b/src/bin/temp_rh_measurement.rs
@@ -1,83 +1,26 @@
 #![no_std]
 #![no_main]
 
+use embassy_nrf::peripherals::TWISPI0;
 use embassy_time::Timer;
 use nrf_softdevice::Softdevice;
 
 use defmt::*;
 use embassy_executor::Spawner;
-use embassy_nrf::gpio::Pin as GpioPin;
-use embassy_nrf::interrupt;
-use embassy_nrf::twim::{self, Instance as TwimInstance, InterruptHandler, Twim};
-use embassy_nrf::{bind_interrupts, peripherals, Peripheral};
+use embassy_nrf::gpio::{Level, Output, OutputDrive};
+use embassy_nrf::twim;
+use embassy_nrf::{bind_interrupts, peripherals};
 use {defmt_rtt as _, panic_probe as _};
 
-struct I2cDriver<'a, T: TwimInstance> {
+struct GenericTempHumiditySensor<T: twim::Instance> {
     address: u8,
-    twim: Twim<'a, T>,
-}
-
-trait Driver {
-    /// The msg being mutable ensures that it doesn't have to be copied into RAM for DMA access, as
-    /// it is already there
-    fn write(&mut self, msg: &mut [u8]);
-    fn read(&mut self, buffer: &mut [u8]);
-}
-
-impl<'a, T: TwimInstance> Driver for I2cDriver<'a, T> {
-    fn write(&mut self, msg: &mut [u8]) {
-        unwrap!(self.twim.blocking_write(self.address, &mut *msg));
-    }
-
-    fn read(&mut self, buffer: &mut [u8]) {
-        unwrap!(self.twim.blocking_read(self.address, &mut *buffer));
-    }
-}
-
-impl<'a, T: TwimInstance> I2cDriver<'a, T> {
-    fn new(
-        address: u8,
-        peripheral: impl Peripheral<P = T> + 'a,
-        sda: impl Peripheral<P = impl GpioPin> + 'a,
-        scl: impl Peripheral<P = impl GpioPin> + 'a,
-        _irq: impl interrupt::typelevel::Binding<T::Interrupt, InterruptHandler<T>> + 'a,
-    ) -> Self {
-        let config = twim::Config::default();
-        let twim = Twim::new(peripheral, _irq, sda, scl, config);
-
-        Self { address, twim }
-    }
-}
-
-struct MockI2cDriver;
-
-impl Driver for MockI2cDriver {
-    fn write(&mut self, _: &mut [u8]) {}
-
-    fn read(&mut self, buffer: &mut [u8]) {
-        buffer[0] = 127;
-        buffer[1] = 128;
-        buffer[2] = 129;
-        buffer[3] = 130;
-        buffer[4] = 131;
-        buffer[5] = 132;
-    }
-}
-
-impl MockI2cDriver {
-    fn new() -> Self {
-        Self {}
-    }
-}
-
-struct TempHumiditySensor<T: Driver> {
-    driver: T,
+    driver: twim::Twim<'static, T>,
 }
 
 // TODO: Implement CRC checks
-impl<T: Driver> TempHumiditySensor<T> {
-    fn new(driver: T) -> Self {
-        Self { driver }
+impl<T: twim::Instance> GenericTempHumiditySensor<T> {
+    fn new(address: u8, driver: twim::Twim<'static, T>) -> Self {
+        Self { address, driver }
     }
 
     /// The procedure for reading out the temperature and humidity and converting them to floats is
@@ -85,9 +28,9 @@ impl<T: Driver> TempHumiditySensor<T> {
     async fn read_temp_and_humidity(&mut self) -> (f32, f32) {
         let mut buf = [0u8; 6];
 
-        self.driver.write(&mut [0xFD]);
+        unwrap!(self.driver.blocking_write(self.address, &mut [0xFD]));
         Timer::after_millis(10).await;
-        self.driver.read(&mut buf);
+        unwrap!(self.driver.blocking_read(self.address, &mut buf));
 
         let temp_int = u16::from_be_bytes([buf[0], buf[1]]);
         let temp_float: f32 = -45f32 + 175f32 * (temp_int as f32 / (2u32.pow(16) - 1) as f32);
@@ -103,16 +46,33 @@ bind_interrupts!(struct Irqs {
     SPIM0_SPIS0_TWIM0_TWIS0_SPI0_TWI0 => twim::InterruptHandler<peripherals::TWISPI0>;
 });
 
-#[embassy_executor::main]
-async fn main(_spawner: Spawner) {
-    let p = embassy_nrf::init(Default::default());
-
-    let driver = I2cDriver::new(0x44, p.TWISPI0, p.P0_14, p.P0_13, Irqs);
-    let mut sensor = TempHumiditySensor::new(driver);
+type TempHumiditySensor = GenericTempHumiditySensor<TWISPI0>;
 
+#[embassy_executor::task]
+async fn measurement_task(mut sensor: TempHumiditySensor) {
     loop {
         let (temp, humidity) = sensor.read_temp_and_humidity().await;
         println!("{} °C\t{} %", temp, humidity);
         Timer::after_millis(50).await;
     }
 }
+
+#[embassy_executor::main]
+async fn main(spawner: Spawner) {
+    let p = embassy_nrf::init(Default::default());
+
+    let config = twim::Config::default();
+    let twi = twim::Twim::new(p.TWISPI0, Irqs, p.P0_14, p.P0_13, config);
+    let sensor = TempHumiditySensor::new(0x44, twi);
+
+    let mut led = Output::new(p.P0_20, Level::Low, OutputDrive::Standard);
+
+    unwrap!(spawner.spawn(measurement_task(sensor)));
+
+    loop {
+        led.set_high();
+        Timer::after_millis(500).await;
+        led.set_low();
+        Timer::after_millis(500).await;
+    }
+}