Module low_power 

Low-power support.

The STM32 line of microcontrollers support various deep-sleep modes which exploit clock-gating to reduce power consumption. embassy-stm32 provides a low-power executor, Executor which can use knowledge of which peripherals are currently blocked upon to transparently and safely enter such low-power modes including STOP1 and STOP2 when idle.

The executor determines which peripherals are active by their RCC state; consequently, low-power states can only be entered if peripherals which block stop have been drop’d and if peripherals that do not block stop are busy. Peripherals which never block stop include:

• GPIO
• RTC

Other peripherals which block stop when busy include (this list may be stale):

• I2C
• USART

Since entering and leaving low-power modes typically incurs a significant latency, the low-power executor will only attempt to enter when the next timer event is at least [config.min_stop_pause] in the future.

use embassy_executor::Spawner;
use embassy_time::Duration;

#[embassy_executor::main(executor = "embassy_stm32::Executor", entry = "cortex_m_rt::entry")]
async fn main(spawner: Spawner) {
    // initialize the platform...
    let mut config = embassy_stm32::Config::default();
    // the default value, but can be adjusted
    config.min_stop_pause = Duration::from_millis(250);
    // when enabled the power-consumption is much higher during stop, but debugging and RTT is working
    config.enable_debug_during_sleep = false;
    let p = embassy_stm32::init(config);

    // your application here...
}

Re-exports

pub use crate::rcc::StopMode;

Structs

DeviceBusy

Prevent the device from going into the stop mode if held

Executor

Thread mode executor, using WFE/SEV.

Functions

stop_ready

Get whether the core is ready to enter the given stop mode.