Merge #440

440: Add i2c example for L4 r=Dirbaio a=lulf

Tested to work on STM32 IOT01A  (STM32L475VG) board.

Co-authored-by: Ulf Lilleengen <ulf.lilleengen@gmail.com>

examples/stm32l4/src/bin/i2c.rs

@@ -0,0 +1,28 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+
+use embassy::executor::Spawner;
+use embassy_stm32::dma::NoDma;
+use embassy_stm32::i2c::I2c;
+use embassy_stm32::interrupt;
+use embassy_stm32::time::Hertz;
+use embassy_stm32::Peripherals;
+use embedded_hal::blocking::i2c::WriteRead;
+use example_common::{info, unwrap};
+
+const ADDRESS: u8 = 0x5F;
+const WHOAMI: u8 = 0x0F;
+
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) -> ! {
+    let irq = interrupt::take!(I2C2_EV);
+    let mut i2c = I2c::new(p.I2C2, p.PB10, p.PB11, irq, NoDma, NoDma, Hertz(100_000));
+
+    let mut data = [0u8; 1];
+    unwrap!(i2c.write_read(ADDRESS, &[WHOAMI], &mut data));
+    info!("Whoami: {}", data[0]);
+}