Add simple i2c example for u5

examples/stm32u5/src/bin/i2c.rs

@@ -0,0 +1,41 @@
+#![no_std]
+#![no_main]
+
+use defmt::{info, unwrap};
+use embassy_executor::Spawner;
+use embassy_stm32::dma::NoDma;
+use embassy_stm32::i2c::I2c;
+use embassy_stm32::time::Hertz;
+use embassy_stm32::{bind_interrupts, i2c, peripherals};
+use {defmt_rtt as _, panic_probe as _};
+
+const HTS221_ADDRESS: u8 = 0x5F;
+const WHOAMI: u8 = 0x0F;
+
+bind_interrupts!(struct Irqs {
+    I2C2_EV => i2c::EventInterruptHandler<peripherals::I2C2>;
+    I2C2_ER => i2c::ErrorInterruptHandler<peripherals::I2C2>;
+});
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    let p = embassy_stm32::init(Default::default());
+    let mut i2c = I2c::new(
+        p.I2C2,
+        p.PH4,
+        p.PH5,
+        Irqs,
+        NoDma,
+        NoDma,
+        Hertz(100_000),
+        Default::default(),
+    );
+
+    let mut data = [0u8; 1];
+    unwrap!(i2c.blocking_write_read(HTS221_ADDRESS, &[WHOAMI], &mut data));
+
+    // HTS221 data sheet is here: https://www.st.com/resource/en/datasheet/hts221.pdf
+    // 7.1 WHO_AM_I command is x0F which expected response xBC.
+    info!("Whoami: 0x{:02x}", data[0]);
+    assert_eq!(0xBC, data[0]);
+}