improvements to semestralka 2

external_led_blinky/src/bin/main.rs

@@ -13,12 +13,12 @@ async fn main(_spawner: Spawner) {
     let p = init(Config::default());
 
     let mut output_pin = Output::new(p.PA3, Level::Low, Speed::Low);
-    let mut artificial_ground = Output::new(p.PB0, Level::Low, Speed::Low);
+    let mut _artificial_ground = Output::new(p.PB0, Level::Low, Speed::Low);
 
     loop {
         output_pin.set_high();
         Timer::after(Duration::from_millis(500)).await;
-        output_pin.set_low();
+        // output_pin.set_low();
         Timer::after(Duration::from_millis(500)).await;
     }
 }

semestralka_2/src/bin/main.rs

@@ -3,7 +3,6 @@
 #![no_main]
 
 use defmt::*;
-use core::ptr::addr_of_mut;
 use embassy_stm32::pac;
 use embassy_executor::Spawner;
 use embassy_futures::yield_now;
@@ -12,7 +11,6 @@ use embassy_stm32::peripherals;
 use embassy_stm32::Config;
 use embassy_stm32::usart::{BufferedUart, Config as UsartConfig, BufferedInterruptHandler};
 use embassy_stm32::gpio::{Output, Level, Speed};
-use embassy_stm32::wdg::IndependentWatchdog;
 use embassy_time::{Duration, Timer};
 
 use static_cell::StaticCell;
@@ -20,38 +18,27 @@ use dma_gpio::config::{
     BAUD, PIPE_HW_RX, PIPE_HW_TX,
 };
 use dma_gpio::hw_uart_pc::{driver::uart_task, usart1};
+use dma_gpio::wakeup::iwdg::{clear_wakeup_flags, init_watchdog};
+use dma_gpio::sleep::shutdown::enter_shutdown;
+use dma_gpio::sleep::standby;
 use {defmt_rtt as _, panic_probe as _};
 
 bind_interrupts!(struct Irqs {
     USART1 => BufferedInterruptHandler<peripherals::USART1>;
 });
 
-unsafe extern "C" {
-    fn HAL_PWR_EnterSTANDBYMode();
-}
-
-const PWR_FLAG_SBF: u32 = 1 << 1;
-
 #[embassy_executor::main]
 async fn main(spawner: Spawner) {
     info!("boot");
-    let mut config = Config::default();
-    config.enable_debug_during_sleep = true;
-    let p = embassy_stm32::init(config);
+    let p = embassy_stm32::init(Config::default());
     let mut led = Output::new(p.PA3, Level::Low, Speed::Low);
     let _led_ground = Output::new(p.PB0, Level::Low, Speed::Low);
     info!("init m8");
 
-    // Clearing after the wakeup 
-    let rcc = pac::RCC;
-    rcc.csr().write(|w| w.set_rmvf(true));
+    clear_wakeup_flags();
 
-    // Check wake source
-    let pwr = pac::PWR;
-    if pwr.sr().read().sbf() {
-        info!("Woke from Standby via watchdog");
-        pwr.sr().write(|w| w.set_sbf(true));
-    }
+    led.set_high();
+    info!("LED ON (MCU awake)");
 
     // HARDWARE UART to the PC
     let mut cfg = UsartConfig::default();
@@ -76,27 +63,17 @@ async fn main(spawner: Spawner) {
     info!("DBGMCU CR: dbg_stop={}, dbg_standby={}", cr.dbg_stop(), cr.dbg_standby());
 
     // MAIN LOOP
-    info!("tick start");
-    led.set_high();
-    info!("LED IS HIGH");
     Timer::after(Duration::from_millis(500)).await;
-    led.set_low();
-    info!("LED IS LOW");
-    Timer::after(Duration::from_millis(500)).await;
-    led.set_high();
-    info!("LED IS HIGH");
 
-    info!("Iwdg init");
-    let mut watchdog = IndependentWatchdog::new(p.IWDG, 2_000_000); // 2 seconds
-    watchdog.unleash();
+    init_watchdog(p.IWDG).await;
     Timer::after(Duration::from_millis(10)).await;
 
-    unsafe {
-        info!("Standby...");
-        HAL_PWR_EnterSTANDBYMode();
-    }
-
     loop {
+        info!("entering shutdown");
+        // enter_shutdown();
+        info!("shutdown");
+        standby::enter_standby_with_sram2_full();
         cortex_m::asm::wfi();
+        yield_now().await;
     }
 }

semestralka_2/src/config.rs

@@ -6,5 +6,7 @@ pub const BAUD: u32 = 9_600;
 pub const PIPE_HW_TX_SIZE: usize = 1024;
 pub const PIPE_HW_RX_SIZE: usize = 1024;
 
+pub const WATCHDOG_TIMEOUT_US: u32 = 2_000_000;  // 2 seconds
+
 pub static PIPE_HW_TX: Pipe<CriticalSectionRawMutex, PIPE_HW_TX_SIZE> = Pipe::new();
 pub static PIPE_HW_RX: Pipe<CriticalSectionRawMutex, PIPE_HW_RX_SIZE> = Pipe::new();

semestralka_2/src/lib.rs

@@ -4,3 +4,5 @@
 // pub use low_power::*;
 pub mod hw_uart_pc;
 pub mod config;
+pub mod sleep;
+pub mod wakeup;

semestralka_2/src/sleep/mod.rs

@@ -0,0 +1,4 @@
+// src/sleep/mod.rs
+
+pub mod standby;
+pub mod shutdown;

semestralka_2/src/sleep/shutdown.rs

@@ -0,0 +1,13 @@
+// src/sleep/standby.rs
+
+pub fn enter_shutdown() -> ! {
+    unsafe extern "C" {
+        fn HAL_PWREx_EnterSHUTDOWNMode();
+    }
+
+    unsafe {
+        HAL_PWREx_EnterSHUTDOWNMode();
+    }
+
+    cortex_m::asm::udf(); //panic
+}

semestralka_2/src/sleep/standby.rs

@@ -0,0 +1,58 @@
+// src/sleep/standby.rs
+
+pub fn enter_standby() -> ! {
+    unsafe extern "C" {
+        fn HAL_PWR_EnterSTANDBYMode();
+    }
+    
+    unsafe {
+        HAL_PWR_EnterSTANDBYMode();
+    }
+    
+    cortex_m::asm::udf(); // never happen marker
+}
+
+pub fn enter_standby_with_sram2_8kb() -> ! {
+    sram2_8kb_retention();
+    enter_standby();
+}
+
+pub fn enter_standby_with_sram2_full() -> ! {
+    sram2_full_retention();
+    enter_standby();
+}
+
+pub fn sram2_full_retention() {
+    unsafe extern "C" {
+        fn HAL_PWREx_EnableSRAM2ContentStandbyRetention(sram2_pages: u32);
+    }
+
+    unsafe {
+        // 0x60 = PWR_SRAM2_FULL_STANDBY = PWR_CR1_RRSB1 | PWR_CR1_RRSB2
+        // See: STM32U5xx HAL: stm32u5xx_hal_pwr_ex.h line 227
+        // PWR_CR1_RRSB1=0x20, PWR_CR1_RRSB2=0x40
+        HAL_PWREx_EnableSRAM2ContentStandbyRetention(0x60);
+    }
+}
+
+pub fn sram2_8kb_retention() {
+    unsafe extern "C" {
+        fn HAL_PWREx_EnableSRAM2ContentStandbyRetention(sram2_pages: u32);
+    }
+
+    unsafe {
+        // 0x40 = PWR_SRAM2_PAGE1_STANDBY = PWR_CR1_RRSB2
+        // 8KB retention only
+        HAL_PWREx_EnableSRAM2ContentStandbyRetention(0x40);
+    }
+}
+
+pub fn disable_sram2_full_retention() {
+    unsafe extern "C" {
+        fn HAL_PWREx_DisableSRAM2ContentStandbyRetention(sram2_pages: u32);
+    }
+
+    unsafe {
+        HAL_PWREx_DisableSRAM2ContentStandbyRetention(0x60);
+    }
+}

semestralka_2/src/wakeup/iwdg.rs

@@ -0,0 +1,50 @@
+// src/wakeup/iwdg.rs
+
+use defmt::info;
+use embassy_stm32::peripherals;
+use embassy_stm32::wdg::IndependentWatchdog;
+use embassy_stm32::Peri;
+use embassy_time::{Duration, Timer};
+use embassy_stm32::pac;
+use crate::sleep::standby;
+
+use crate::config::WATCHDOG_TIMEOUT_US;
+
+/// Clears system reset and standby flags after wakeup.
+///
+/// Call early in startup to:
+/// - Clear reset flags by setting `RMVF` in `RCC_CSR`.
+/// - If `SBF` in `PWR_SR` is set (woke from Standby), clear it.
+///
+/// # Registers
+/// - `RCC_CSR` — Reset and Clock Control / Status
+/// - `PWR_SR` — Power Control / Status
+pub fn clear_wakeup_flags() {
+    info!("Clearing wakeup flags...");
+    standby::disable_sram2_full_retention();
+
+    // Clear reset flags
+    // let rcc = unsafe { &*pac::RCC::ptr() };
+    let rcc = pac::RCC;
+    rcc.csr().write(|w| w.set_rmvf(true));
+
+    // Check and clear Standby wakeup flag
+    // let pwr = unsafe { &*pac::PWR::ptr() };
+    let pwr = pac::PWR;
+    if pwr.sr().read().sbf() {
+        info!("Woke from Standby mode");
+        pwr.sr().write(|w| w.set_sbf(true));
+    }
+}
+
+/// Initializes the Independent Watchdog (IWDG) timer.
+/// Wakeup source: Can wake the system from Standby mode on timeout
+///
+/// # Timing
+/// - Timeout value is configured in `WATCHDOG_TIMEOUT_US` from config.rs
+pub async fn init_watchdog(iwdg: Peri<'_, peripherals::IWDG>) {
+    info!("Initializing watchdog after watchdog wake...");
+    let mut watchdog = IndependentWatchdog::new(iwdg, WATCHDOG_TIMEOUT_US);
+    watchdog.unleash();
+    Timer::after(Duration::from_millis(10)).await;
+}

semestralka_2/src/wakeup/mod.rs

@@ -0,0 +1,3 @@
+// src/wakeup/mod.rs
+
+pub mod iwdg;