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:mod:`machine` --- functions related to the board
=================================================
.. module:: machine
:synopsis: functions related to the board
The ``machine`` module contains specific functions related to the board.
Reset related functions
-----------------------
.. function:: reset()
Resets the device in a manner similar to pushing the external RESET
button.
.. function:: reset_cause()
Get the reset cause. See :ref:`constants <machine_constants>` for the possible return values.
Interrupt related functions
---------------------------
.. function:: disable_irq()
Disable interrupt requests.
Returns the previous IRQ state: ``False``/``True`` for disabled/enabled IRQs
respectively. This return value can be passed to enable_irq to restore
the IRQ to its original state.
.. function:: enable_irq(state=True)
Enable interrupt requests.
If ``state`` is ``True`` (the default value) then IRQs are enabled.
If ``state`` is ``False`` then IRQs are disabled. The most common use of
this function is to pass it the value returned by ``disable_irq`` to
exit a critical section.
Power related functions
-----------------------
.. function:: freq()
.. only:: not port_wipy
Returns CPU frequency in hertz.
.. only:: port_wipy
Returns a tuple of clock frequencies: ``(sysclk,)``
These correspond to:
- sysclk: frequency of the CPU
.. function:: idle()
Gates the clock to the CPU, useful to reduce power consumption at any time during
short or long periods. Peripherals continue working and execution resumes as soon
as any interrupt is triggered (on many ports this includes system timer
interrupt occuring at regular intervals on the order of millisecond).
.. function:: sleep()
Stops the CPU and disables all peripherals except for WLAN. Execution is resumed from
the point where the sleep was requested. For wake up to actually happen, wake sources
should be configured first.
.. function:: deepsleep()
Stops the CPU and all peripherals (including networking interfaces, if any). Execution
is resumed from the main script, just as with a reset. The reset cause can be checked
to know that we are coming from ``machine.DEEPSLEEP``. For wake up to actually happen,
wake sources should be configured first, like ``Pin`` change or ``RTC`` timeout.
.. only:: port_wipy
.. function:: wake_reason()
Get the wake reason. See :ref:`constants <machine_constants>` for the possible return values.
Miscellaneous functions
-----------------------
.. only:: port_wipy
.. function:: main(filename)
Set the filename of the main script to run after boot.py is finished. If
this function is not called then the default file main.py will be executed.
It only makes sense to call this function from within boot.py.
.. function:: rng()
Return a 24-bit software generated random number.
.. function:: unique_id()
Returns a byte string with a unique idenifier of a board/SoC. It will vary
from a board/SoC instance to another, if underlying hardware allows. Length
varies by hardware (so use substring of a full value if you expect a short
ID). In some MicroPython ports, ID corresponds to the network MAC address.
.. function:: time_pulse_us(pin, pulse_level, timeout_us=1000000)
Time a pulse on the given `pin`, and return the duration of the pulse in
microseconds. The `pulse_level` argument should be 0 to time a low pulse
or 1 to time a high pulse.
The function first waits while the pin input is different to the `pulse_level`
parameter, then times the duration that the pin is equal to `pulse_level`.
If the pin is already equal to `pulse_level` then timing starts straight away.
The function will raise an OSError with ETIMEDOUT if either of the waits is
longer than the given timeout value (which is in microseconds).
.. _machine_constants:
Constants
---------
.. data:: machine.IDLE
.. data:: machine.SLEEP
.. data:: machine.DEEPSLEEP
irq wake values
.. data:: machine.POWER_ON
.. data:: machine.HARD_RESET
.. data:: machine.WDT_RESET
.. data:: machine.DEEPSLEEP_RESET
.. data:: machine.SOFT_RESET
reset causes
.. data:: machine.WLAN_WAKE
.. data:: machine.PIN_WAKE
.. data:: machine.RTC_WAKE
wake reasons
Classes
-------
.. toctree::
:maxdepth: 1
machine.ADC.rst
machine.I2C.rst
machine.Pin.rst
machine.RTC.rst
machine.SD.rst
machine.SPI.rst
machine.Timer.rst
machine.UART.rst
machine.WDT.rst
|
