examples: Switch to embassy-stm32 as a pac provider

stmf32f1xx doesn't yet support embedded-hal 1.0. Switch to embassy-stm32
as a pac provider, which can be used in both a sync and async setups.

Unfortunately for blocking i2c support embassy git has to be used rather
then a releaed version. Also for i2c move the expected configuration
from PB8/PB9 to PB6/PB7 to avoid the needed for pin remapping, which
embassy doesn't yet support on stm32f1xx chips

Author: sjoerdsimons

.cargo/config.toml

@@ -2,6 +2,8 @@
 runner = [ "probe-rs", "run", "--chip", "STM32F103C8" ]
 rustflags = [
   "-C", "link-arg=-Tlink.x",
+  "-C", "link-arg=--nmagic",
+  "-C", "link-arg=-Tdefmt.x",
 ]
 
 [build]

Cargo.toml

@@ -24,23 +24,27 @@ display-interface-spi = "0.5.0"
 embedded-graphics-core = { version = "0.4.0", optional = true }
 
 [dev-dependencies]
-cortex-m = "0.7.2"
+cortex-m = { version = "0.7.2", features = ["critical-section-single-core"] }
 cortex-m-rt = "0.7.3"
 cortex-m-rtic = "1.1.4"
-panic-halt = "0.2.0"
-cast = { version = "0.2.6", default-features = false }
+defmt = "0.3.6"
+defmt-rtt = "0.4.0"
+panic-probe = { version = "0.3.1", features = ["print-defmt"] }
 # Used to load BMP images in various examples
 tinybmp = "0.5.0"
 embedded-graphics = "0.8.0"
 # Used by the noise_i2c examples
 rand = { version = "0.8.4", default-features = false, features = [ "small_rng" ] }
-stm32f1xx-hal = { version = "0.10.0", features = [ "rt", "stm32f103" ] }
+embassy-stm32 = { version = "0.1.0", git = "https://github.com/embassy-rs/embassy", features = [ "stm32f103c8", "memory-x", "defmt", "exti", "time-driver-tim3" , "unstable-pac"]  }
+embassy-time = { version = "0.3.1", git = "https://github.com/embassy-rs/embassy" }
+embedded-hal-bus = "0.2.0"
 
 [features]
 default = ["graphics"]
 graphics = ["embedded-graphics-core"]
 
 [profile.dev]
+opt-level="s"
 codegen-units = 1
 incremental = false
 

build.rs

@@ -12,55 +12,34 @@
 //!      Display -> Blue Pill
 //! (black)  GND -> GND
 //! (red)    +5V -> VCC
-//! (yellow) SDA -> PB9
-//! (green)  SCL -> PB8
+//! (yellow) SDA -> PB7
+//! (green)  SCL -> PB6
 //! ```
 //!
 //! Run on a Blue Pill with `cargo run --example image_i2c`.
 
 #![no_std]
 #![no_main]
 
-use cortex_m_rt::{entry, exception, ExceptionFrame};
+use cortex_m::asm::nop;
+use cortex_m_rt::entry;
+use defmt_rtt as _;
+use embassy_stm32::time::Hertz;
 use embedded_graphics::{image::Image, pixelcolor::Rgb565, prelude::*};
-use panic_halt as _;
+use panic_probe as _;
 use ssd1306::{prelude::*, I2CDisplayInterface, Ssd1306};
-use stm32f1xx_hal::{
-    i2c::{BlockingI2c, DutyCycle, Mode},
-    prelude::*,
-    stm32,
-};
+
 use tinybmp::Bmp;
 
 #[entry]
 fn main() -> ! {
-    let dp = stm32::Peripherals::take().unwrap();
-
-    let mut flash = dp.FLASH.constrain();
-    let rcc = dp.RCC.constrain();
-
-    let clocks = rcc.cfgr.freeze(&mut flash.acr);
-
-    let mut afio = dp.AFIO.constrain();
-
-    let mut gpiob = dp.GPIOB.split();
-
-    let scl = gpiob.pb8.into_alternate_open_drain(&mut gpiob.crh);
-    let sda = gpiob.pb9.into_alternate_open_drain(&mut gpiob.crh);
-
-    let i2c = BlockingI2c::i2c1(
-        dp.I2C1,
-        (scl, sda),
-        &mut afio.mapr,
-        Mode::Fast {
-            frequency: 400_000.Hz(),
-            duty_cycle: DutyCycle::Ratio2to1,
-        },
-        clocks,
-        1000,
-        10,
-        1000,
-        1000,
+    let p = embassy_stm32::init(Default::default());
+    let i2c = embassy_stm32::i2c::I2c::new_blocking(
+        p.I2C1,
+        p.PB6,
+        p.PB7,
+        Hertz::khz(400),
+        Default::default(),
     );
 
     let interface = I2CDisplayInterface::new(i2c);
@@ -80,10 +59,7 @@ fn main() -> ! {
 
     display.flush().unwrap();
 
-    loop {}
-}
-
-#[exception]
-unsafe fn HardFault(ef: &ExceptionFrame) -> ! {
-    panic!("{:#?}", ef);
+    loop {
+        nop()
+    }
 }

examples/bmp_i2c.rs

@@ -9,74 +9,53 @@
 //! ```
 //! GND -> GND
 //! 3V3 -> VCC
-//! PA5 -> SCL
-//! PA7 -> SDA
+//! PA5 -> SCL (D0)
+//! PA7 -> SDA (D1)
 //! PB0 -> RST
 //! PB1 -> D/C
+//! PB10 -> CS
 //! ```
 //!
 //! Run on a Blue Pill with `cargo run --example graphics`.
 
 #![no_std]
 #![no_main]
 
-use cortex_m_rt::{entry, exception, ExceptionFrame};
+use cortex_m::asm::nop;
+use cortex_m_rt::entry;
+use defmt_rtt as _;
+use embassy_stm32::{
+    gpio,
+    spi::{self, Spi},
+    time::Hertz,
+};
 use embedded_graphics::{
     pixelcolor::BinaryColor,
     prelude::*,
     primitives::{Circle, PrimitiveStyleBuilder, Rectangle, Triangle},
 };
-use panic_halt as _;
+use panic_probe as _;
 use ssd1306::{prelude::*, Ssd1306};
-use stm32f1xx_hal::{
-    prelude::*,
-    spi::{Mode, Phase, Polarity, Spi},
-    stm32,
-    timer::Timer,
-};
 
 #[entry]
 fn main() -> ! {
-    let cp = cortex_m::Peripherals::take().unwrap();
-    let dp = stm32::Peripherals::take().unwrap();
-
-    let mut flash = dp.FLASH.constrain();
-    let rcc = dp.RCC.constrain();
-
-    let clocks = rcc.cfgr.freeze(&mut flash.acr);
-
-    let mut afio = dp.AFIO.constrain();
-
-    let mut gpioa = dp.GPIOA.split();
-    let mut gpiob = dp.GPIOB.split();
+    let p = embassy_stm32::init(Default::default());
+    let mut config = spi::Config::default();
+    config.frequency = Hertz::mhz(8);
+    let spi = Spi::new_blocking_txonly(p.SPI1, p.PA5, p.PA7, config);
 
-    // SPI1
-    let sck = gpioa.pa5.into_alternate_push_pull(&mut gpioa.crl);
-    let miso = gpioa.pa6;
-    let mosi = gpioa.pa7.into_alternate_push_pull(&mut gpioa.crl);
-
-    let mut delay = Timer::syst(cp.SYST, &clocks).delay();
-
-    let mut rst = gpiob.pb0.into_push_pull_output(&mut gpiob.crl);
-    let dc = gpiob.pb1.into_push_pull_output(&mut gpiob.crl);
-
-    let spi = Spi::spi1(
-        dp.SPI1,
-        (sck, miso, mosi),
-        &mut afio.mapr,
-        Mode {
-            polarity: Polarity::IdleLow,
-            phase: Phase::CaptureOnFirstTransition,
-        },
-        8.MHz(),
-        clocks,
-    );
+    let mut rst = gpio::Output::new(p.PB0, gpio::Level::Low, gpio::Speed::Low);
+    let dc = gpio::Output::new(p.PB1, gpio::Level::Low, gpio::Speed::Low);
+    let cs = gpio::Output::new(p.PB10, gpio::Level::Low, gpio::Speed::Low);
+    let spi = embedded_hal_bus::spi::ExclusiveDevice::new_no_delay(spi, cs).unwrap();
 
     let interface = display_interface_spi::SPIInterface::new(spi, dc);
     let mut display = Ssd1306::new(interface, DisplaySize128x64, DisplayRotation::Rotate0)
         .into_buffered_graphics_mode();
 
-    display.reset(&mut rst, &mut delay).unwrap();
+    display
+        .reset(&mut rst, &mut embassy_time::Delay {})
+        .unwrap();
     display.init().unwrap();
 
     let yoffset = 20;
@@ -118,10 +97,7 @@ fn main() -> ! {
 
     display.flush().unwrap();
 
-    loop {}
-}
-
-#[exception]
-unsafe fn HardFault(ef: &ExceptionFrame) -> ! {
-    panic!("{:#?}", ef);
+    loop {
+        nop()
+    }
 }

examples/graphics.rs

@@ -8,58 +8,36 @@
 //!      Display -> Blue Pill
 //! (black)  GND -> GND
 //! (red)    +5V -> VCC
-//! (yellow) SDA -> PB9
-//! (green)  SCL -> PB8
+//! (yellow) SDA -> PB7
+//! (green)  SCL -> PB6
 //! ```
 //!
 //! Run on a Blue Pill with `cargo run --example graphics_i2c`.
 
 #![no_std]
 #![no_main]
 
-use cortex_m_rt::{entry, exception, ExceptionFrame};
+use cortex_m::asm::nop;
+use cortex_m_rt::entry;
+use defmt_rtt as _;
+use embassy_stm32::time::Hertz;
 use embedded_graphics::{
     pixelcolor::BinaryColor,
     prelude::*,
     primitives::{Circle, PrimitiveStyleBuilder, Rectangle, Triangle},
 };
-use panic_halt as _;
+use panic_probe as _;
 use ssd1306::{prelude::*, I2CDisplayInterface, Ssd1306};
-use stm32f1xx_hal::{
-    i2c::{BlockingI2c, DutyCycle, Mode},
-    prelude::*,
-    stm32,
-};
 
 #[entry]
 fn main() -> ! {
-    let dp = stm32::Peripherals::take().unwrap();
-
-    let mut flash = dp.FLASH.constrain();
-    let rcc = dp.RCC.constrain();
-
-    let clocks = rcc.cfgr.freeze(&mut flash.acr);
-
-    let mut afio = dp.AFIO.constrain();
-
-    let mut gpiob = dp.GPIOB.split();
-
-    let scl = gpiob.pb8.into_alternate_open_drain(&mut gpiob.crh);
-    let sda = gpiob.pb9.into_alternate_open_drain(&mut gpiob.crh);
-
-    let i2c = BlockingI2c::i2c1(
-        dp.I2C1,
-        (scl, sda),
-        &mut afio.mapr,
-        Mode::Fast {
-            frequency: 400_000.Hz(),
-            duty_cycle: DutyCycle::Ratio2to1,
-        },
-        clocks,
-        1000,
-        10,
-        1000,
-        1000,
+    let p = embassy_stm32::init(Default::default());
+    let i2c = embassy_stm32::i2c::I2c::new_blocking(
+        p.I2C1,
+        p.PB6,
+        p.PB7,
+        Hertz::khz(400),
+        Default::default(),
     );
 
     let interface = I2CDisplayInterface::new(i2c);
@@ -106,10 +84,7 @@ fn main() -> ! {
 
     display.flush().unwrap();
 
-    loop {}
-}
-
-#[exception]
-unsafe fn HardFault(ef: &ExceptionFrame) -> ! {
-    panic!("{:#?}", ef);
+    loop {
+        nop()
+    }
 }