From 3ef62eef5370b34792a737dd5a4b296fe3fd8c7d Mon Sep 17 00:00:00 2001
From: Felipe Balbi <febalbi@microsoft.com>
Date: Thu, 16 May 2024 08:12:18 -0700
Subject: [PATCH] stm32h7: add shared bus example
---
examples/stm32h7/Cargo.toml | 1 +
examples/stm32h7/src/bin/i2c_shared.rs | 112 +++++++++++++++++++++++++
2 files changed, 113 insertions(+)
create mode 100644 examples/stm32h7/src/bin/i2c_shared.rs
diff --git a/examples/stm32h7/Cargo.toml b/examples/stm32h7/Cargo.toml
index a09af4b97..c6c2d1354 100644
--- a/examples/stm32h7/Cargo.toml
+++ b/examples/stm32h7/Cargo.toml
@@ -8,6 +8,7 @@ license = "MIT OR Apache-2.0"
# Change stm32h743bi to your chip name, if necessary.
embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["defmt", "stm32h743bi", "time-driver-tim2", "exti", "memory-x", "unstable-pac", "chrono"] }
embassy-sync = { version = "0.5.0", path = "../../embassy-sync", features = ["defmt"] }
+embassy-embedded-hal = { version = "0.1.0", path = "../../embassy-embedded-hal" }
embassy-executor = { version = "0.5.0", path = "../../embassy-executor", features = ["task-arena-size-32768", "arch-cortex-m", "executor-thread", "executor-interrupt", "defmt", "integrated-timers"] }
embassy-time = { version = "0.3.0", path = "../../embassy-time", features = ["defmt", "defmt-timestamp-uptime", "tick-hz-32_768"] }
embassy-net = { version = "0.4.0", path = "../../embassy-net", features = ["defmt", "tcp", "dhcpv4", "medium-ethernet", "proto-ipv6", "dns"] }
diff --git a/examples/stm32h7/src/bin/i2c_shared.rs b/examples/stm32h7/src/bin/i2c_shared.rs
new file mode 100644
index 000000000..79d213ae4
--- /dev/null
+++ b/examples/stm32h7/src/bin/i2c_shared.rs
@@ -0,0 +1,112 @@
+#![no_std]
+#![no_main]
+
+use core::cell::RefCell;
+
+use defmt::*;
+use embassy_embedded_hal::shared_bus::blocking::i2c::I2cDevice;
+use embassy_executor::Spawner;
+use embassy_stm32::bind_interrupts;
+use embassy_stm32::i2c::{self, I2c};
+use embassy_stm32::mode::Async;
+use embassy_stm32::peripherals::{self, I2C1};
+use embassy_stm32::time::Hertz;
+use embassy_sync::blocking_mutex::NoopMutex;
+use embassy_time::{Duration, Timer};
+use static_cell::StaticCell;
+use {defmt_rtt as _, panic_probe as _};
+
+const TMP117_ADDR: u8 = 0x48;
+const TMP117_TEMP_RESULT: u8 = 0x00;
+
+const SHTC3_ADDR: u8 = 0x70;
+const SHTC3_WAKEUP: [u8; 2] = [0x35, 0x17];
+const SHTC3_MEASURE_RH_FIRST: [u8; 2] = [0x5c, 0x24];
+const SHTC3_SLEEP: [u8; 2] = [0xb0, 0x98];
+
+static I2C_BUS: StaticCell<NoopMutex<RefCell<I2c<'static, I2C1, Async>>>> = StaticCell::new();
+
+bind_interrupts!(struct Irqs {
+ I2C1_EV => i2c::EventInterruptHandler<peripherals::I2C1>;
+ I2C1_ER => i2c::ErrorInterruptHandler<peripherals::I2C1>;
+});
+
+#[embassy_executor::task]
+async fn temperature(mut i2c: impl embedded_hal_1::i2c::I2c + 'static) {
+ let mut data = [0u8; 2];
+
+ loop {
+ match i2c.write_read(TMP117_ADDR, &[TMP117_TEMP_RESULT], &mut data) {
+ Ok(()) => {
+ let temp = f32::from(i16::from_be_bytes(data)) * 7.8125 / 1000.0;
+ info!("Temperature {}", temp);
+ }
+ Err(_) => error!("I2C Error"),
+ }
+
+ Timer::after(Duration::from_millis(1000)).await;
+ }
+}
+
+#[embassy_executor::task]
+async fn humidity(mut i2c: impl embedded_hal_1::i2c::I2c + 'static) {
+ let mut data = [0u8; 6];
+
+ loop {
+ // Wakeup
+ match i2c.write(SHTC3_ADDR, &SHTC3_WAKEUP) {
+ Ok(()) => Timer::after(Duration::from_millis(20)).await,
+ Err(_) => error!("I2C Error"),
+ }
+
+ // Measurement
+ match i2c.write(SHTC3_ADDR, &SHTC3_MEASURE_RH_FIRST) {
+ Ok(()) => Timer::after(Duration::from_millis(5)).await,
+ Err(_) => error!("I2C Error"),
+ }
+
+ // Result
+ match i2c.read(SHTC3_ADDR, &mut data) {
+ Ok(()) => Timer::after(Duration::from_millis(5)).await,
+ Err(_) => error!("I2C Error"),
+ }
+
+ // Sleep
+ match i2c.write(SHTC3_ADDR, &SHTC3_SLEEP) {
+ Ok(()) => {
+ let (bytes, _) = data.split_at(core::mem::size_of::<i16>());
+ let rh = f32::from(u16::from_be_bytes(bytes.try_into().unwrap())) * 100.0 / 65536.0;
+ info!("Humidity: {}", rh);
+ }
+ Err(_) => error!("I2C Error"),
+ }
+
+ Timer::after(Duration::from_millis(1000)).await;
+ }
+}
+
+#[embassy_executor::main]
+async fn main(spawner: Spawner) {
+ let p = embassy_stm32::init(Default::default());
+
+ let i2c = I2c::new(
+ p.I2C1,
+ p.PB8,
+ p.PB9,
+ Irqs,
+ p.DMA1_CH4,
+ p.DMA1_CH5,
+ Hertz(100_000),
+ Default::default(),
+ );
+ let i2c_bus = NoopMutex::new(RefCell::new(i2c));
+ let i2c_bus = I2C_BUS.init(i2c_bus);
+
+ // Device 1, using embedded-hal-async compatible driver for TMP117
+ let i2c_dev1 = I2cDevice::new(i2c_bus);
+ spawner.spawn(temperature(i2c_dev1)).unwrap();
+
+ // Device 2, using embedded-hal-async compatible driver for SHTC3
+ let i2c_dev2 = I2cDevice::new(i2c_bus);
+ spawner.spawn(humidity(i2c_dev2)).unwrap();
+}