5 files changed, 116 insertions, 12 deletions

diff --git a/examples/stm32wle5/README.md b/examples/stm32wle5/README.md
index 63507f490..18c3b5071 100644
--- a/examples/stm32wle5/README.md
+++ b/examples/stm32wle5/README.md
@@ -15,6 +15,7 @@ All examples will set all pins to analog mode before configuring pins for the ex
 - the `adc` example will sleep in STOP1 betwen samples and the chip will only draw about 13uA while sleeping
 - the `blinky` example will sleep in STOP2 and the chip will only draw 1uA or less while sleeping
 - the `button_exti` example will sleep in STOP2 and the chip will only draw 1uA or less while sleeping
+- the `i2c` examples will sleep in STOP1 between reads and the chip only draw about 10uA while sleeping
 
 For each example you will need to start `defmt-print` with the example binary and the correct serial port in a seperate terminal.  Example:
 ```
diff --git a/examples/stm32wle5/src/bin/adc.rs b/examples/stm32wle5/src/bin/adc.rs
index fabdb9cb3..b4af656ed 100644
--- a/examples/stm32wle5/src/bin/adc.rs
+++ b/examples/stm32wle5/src/bin/adc.rs
@@ -65,10 +65,7 @@ async fn async_main(_spawner: Spawner) {
     {
         use embassy_stm32::mode::Blocking;
         use embassy_stm32::usart::Uart;
-        let mut config = embassy_stm32::usart::Config::default();
-        config.baudrate = 115200;
-        config.assume_noise_free = true;
-        config.detect_previous_overrun = true;
+        let config = embassy_stm32::usart::Config::default();
         let uart = Uart::new_blocking(p.LPUART1, p.PC0, p.PC1, config).expect("failed to configure UART!");
         static SERIAL: StaticCell<Uart<'static, Blocking>> = StaticCell::new();
         defmt_serial::defmt_serial(SERIAL.init(uart));
diff --git a/examples/stm32wle5/src/bin/blinky.rs b/examples/stm32wle5/src/bin/blinky.rs
index f5ba97025..a7a571cb1 100644
--- a/examples/stm32wle5/src/bin/blinky.rs
+++ b/examples/stm32wle5/src/bin/blinky.rs
@@ -63,10 +63,7 @@ async fn async_main(_spawner: Spawner) {
     {
         use embassy_stm32::mode::Blocking;
         use embassy_stm32::usart::Uart;
-        let mut config = embassy_stm32::usart::Config::default();
-        config.baudrate = 115200;
-        config.assume_noise_free = true;
-        config.detect_previous_overrun = true;
+        let config = embassy_stm32::usart::Config::default();
         let uart = Uart::new_blocking(p.LPUART1, p.PC0, p.PC1, config).expect("failed to configure UART!");
         static SERIAL: StaticCell<Uart<'static, Blocking>> = StaticCell::new();
         defmt_serial::defmt_serial(SERIAL.init(uart));
diff --git a/examples/stm32wle5/src/bin/button_exti.rs b/examples/stm32wle5/src/bin/button_exti.rs
index dfa391a81..c8083a240 100644
--- a/examples/stm32wle5/src/bin/button_exti.rs
+++ b/examples/stm32wle5/src/bin/button_exti.rs
@@ -65,10 +65,7 @@ async fn async_main(_spawner: Spawner) {
     {
         use embassy_stm32::mode::Blocking;
         use embassy_stm32::usart::Uart;
-        let mut config = embassy_stm32::usart::Config::default();
-        config.baudrate = 115200;
-        config.assume_noise_free = true;
-        config.detect_previous_overrun = true;
+        let config = embassy_stm32::usart::Config::default();
         let uart = Uart::new_blocking(p.LPUART1, p.PC0, p.PC1, config).expect("failed to configure UART!");
         static SERIAL: StaticCell<Uart<'static, Blocking>> = StaticCell::new();
         defmt_serial::defmt_serial(SERIAL.init(uart));
diff --git a/examples/stm32wle5/src/bin/i2c.rs b/examples/stm32wle5/src/bin/i2c.rs
new file mode 100644
index 000000000..4a56773e9
--- /dev/null
+++ b/examples/stm32wle5/src/bin/i2c.rs
@@ -0,0 +1,112 @@
+#![no_std]
+#![no_main]
+
+use defmt::*;
+#[cfg(feature = "defmt-rtt")]
+use defmt_rtt as _;
+use embassy_executor::Spawner;
+use embassy_stm32::i2c::I2c;
+use embassy_stm32::low_power::Executor;
+use embassy_stm32::rtc::{Rtc, RtcConfig};
+use embassy_stm32::time::Hertz;
+use embassy_stm32::{bind_interrupts, i2c, peripherals};
+use embassy_time::{Duration, Timer};
+use panic_probe as _;
+use static_cell::StaticCell;
+
+bind_interrupts!(struct IrqsI2C{
+    I2C2_EV => i2c::EventInterruptHandler<peripherals::I2C2>;
+    I2C2_ER => i2c::ErrorInterruptHandler<peripherals::I2C2>;
+});
+
+#[cortex_m_rt::entry]
+fn main() -> ! {
+    info!("main: Starting!");
+    Executor::take().run(|spawner| {
+        spawner.spawn(unwrap!(async_main(spawner)));
+    });
+}
+
+#[embassy_executor::task]
+async fn async_main(_spawner: Spawner) {
+    let mut config = embassy_stm32::Config::default();
+    // enable HSI clock
+    config.rcc.hsi = true;
+    // enable LSI clock for RTC
+    config.rcc.ls = embassy_stm32::rcc::LsConfig::default_lsi();
+    config.rcc.msi = Some(embassy_stm32::rcc::MSIRange::RANGE4M);
+    config.rcc.sys = embassy_stm32::rcc::Sysclk::MSI;
+    // enable ADC with HSI clock
+    config.rcc.mux.i2c2sel = embassy_stm32::pac::rcc::vals::I2c2sel::HSI;
+    #[cfg(feature = "defmt-serial")]
+    {
+        // disable debug during sleep to reduce power consumption since we are
+        // using defmt-serial on LPUART1.
+        config.enable_debug_during_sleep = false;
+        // if we are using defmt-serial on LPUART1, we need to use HSI for the clock
+        // so that its registers are preserved during STOP modes.
+        config.rcc.mux.lpuart1sel = embassy_stm32::pac::rcc::vals::Lpuart1sel::HSI;
+    }
+    // Initialize STM32WL peripherals (use default config like wio-e5-async example)
+    let p = embassy_stm32::init(config);
+
+    // start with all GPIOs as analog to reduce power consumption
+    for r in [
+        embassy_stm32::pac::GPIOA,
+        embassy_stm32::pac::GPIOB,
+        embassy_stm32::pac::GPIOC,
+        embassy_stm32::pac::GPIOH,
+    ] {
+        r.moder().modify(|w| {
+            for i in 0..16 {
+                // don't reset these if probe-rs should stay connected!
+                #[cfg(feature = "defmt-rtt")]
+                if config.enable_debug_during_sleep && r == embassy_stm32::pac::GPIOA && [13, 14].contains(&i) {
+                    continue;
+                }
+                w.set_moder(i, embassy_stm32::pac::gpio::vals::Moder::ANALOG);
+            }
+        });
+    }
+    #[cfg(feature = "defmt-serial")]
+    {
+        use embassy_stm32::mode::Blocking;
+        use embassy_stm32::usart::Uart;
+        let config = embassy_stm32::usart::Config::default();
+        let uart = Uart::new_blocking(p.LPUART1, p.PC0, p.PC1, config).expect("failed to configure UART!");
+        static SERIAL: StaticCell<Uart<'static, Blocking>> = StaticCell::new();
+        defmt_serial::defmt_serial(SERIAL.init(uart));
+    }
+
+    // give the RTC to the low_power executor...
+    let rtc_config = RtcConfig::default();
+    let rtc = Rtc::new(p.RTC, rtc_config);
+    static RTC: StaticCell<Rtc> = StaticCell::new();
+    let rtc = RTC.init(rtc);
+    embassy_stm32::low_power::stop_with_rtc(rtc);
+
+    info!("Hello World!");
+    let en3v3 = embassy_stm32::gpio::Output::new(
+        p.PA9,
+        embassy_stm32::gpio::Level::High,
+        embassy_stm32::gpio::Speed::High,
+    );
+    core::mem::forget(en3v3); // keep the output pin enabled
+
+    let mut i2c = I2c::new(p.I2C2, p.PB15, p.PA15, IrqsI2C, p.DMA1_CH6, p.DMA1_CH7, {
+        let mut config = i2c::Config::default();
+        config.frequency = Hertz::khz(100);
+        config.timeout = Duration::from_millis(500);
+        config
+    });
+
+    loop {
+        let mut buffer = [0; 2];
+        // read the temperature register of the onboard lm75
+        match i2c.read(0x48, &mut buffer).await {
+            Ok(_) => info!("--> {:?}", buffer),
+            Err(e) => info!("--> Error: {:?}", e),
+        }
+        Timer::after_secs(5).await;
+    }
+}