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STM32LowPower

Arduino library to support Low Power

API

  • void begin(): configure the Low Power

  • void idle(uint32_t millis): enter in idle mode
    param millis (optional): number of milliseconds before to exit the mode. At least 1000 ms. The RTC is used in alarm mode to wakeup the chip in millis milliseconds.

  • void sleep(uint32_t millis): enter in sleep mode
    param millis (optional): number of milliseconds before to exit the mode. At least 1000 ms. The RTC is used in alarm mode to wakeup the chip in millis milliseconds.

  • void deepSleep(uint32_t millis): enter in deepSleep mode
    param millis (optional): number of milliseconds before to exit the mode. At least 1000 ms. The RTC is used in alarm mode to wakeup the chip in millis milliseconds.

  • void shutdown(uint32_t millis): enter in shutdown mode param millis (optional): number of milliseconds before to exit the mode. At least 1000 ms. The RTC is used in alarm mode to wakeup the board in millis milliseconds.

  • void attachInterruptWakeup(uint32_t pin, voidFuncPtrVoid callback, uint32_t mode): Enable GPIO pin in interrupt mode. If the pin is a wakeup pin, it is configured as wakeup source (see board documentation).
    param pin: pin number
    param callback: pointer to callback
    param mode: interrupt mode (HIGH, LOW, RISING, FALLING or CHANGE)

  • void enableWakeupFrom(HardwareSerial *serial, voidFuncPtrVoid callback): enable a UART peripheral in low power mode. See board documentation for low power mode compatibility.
    param serial: pointer to a UART
    param callback: pointer to a callback to call when the board is waked up.

  • void enableWakeupFrom(TwoWire *wire, voidFuncPtrVoid callback): enable an I2C peripheral in low power mode. See board documentation for low power mode compatibility.
    param wire: pointer to I2C
    param callback: pointer to a callback to call when the board is waked up.

  • void enableWakeupFrom(STM32RTC *rtc, voidFuncPtr callback) attach a callback to the RTC peripheral.
    param rtc: pointer to RTC
    param callback: pointer to a callback to call when the board is waked up.

Begin() function must be called at least once before idle(), sleep(), deepSleep() or shutdown() functions.

attachInterruptWakeup() or enableWakeupFrom() functions should be called before idle(), sleep(), deepSleep() or shutdown() functions.

The board will restart when exit the deepSleep or shutdown mode.

Hardware state

  • Idle mode: low wake-up latency (µs range) (e.g. ARM WFI). Memories and voltage supplies are retained. Minimal power saving mainly on the core itself.

  • sleep mode: low wake-up latency (µs range) (e.g. ARM WFI), Memories and voltage supplies are retained. Minimal power saving mainly on the core itself but higher than idle mode.

  • deep sleep mode: medium latency (ms range), clocks are gated to reduced. Memories and voltage supplies are retained. If supported, Peripherals wake-up is possible (UART, I2C ...).

  • shutdown mode: high wake-up latency (posible hundereds of ms or second timeframe), voltage supplies are cut except always-on domain, memory content are lost and system basically reboots.

Source

You can find the source files at
https://github.com/stm32duino/STM32LowPower