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.. currentmodule:: machine
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.. _machine.WDT:
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class WDT -- watchdog timer
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===========================
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The WDT is used to restart the system when the application crashes and ends
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up into a non recoverable state. Once started it cannot be stopped or
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reconfigured in any way. After enabling, the application must "feed" the
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watchdog periodically to prevent it from expiring and resetting the system.
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Example usage::
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from machine import WDT
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wdt = WDT(timeout=2000) # enable it with a timeout of 2s
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wdt.feed()
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Availability of this class: pyboard, WiPy, esp8266, esp32.
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Constructors
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------------
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.. class:: WDT(id=0, timeout=5000)
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Create a WDT object and start it. The timeout must be given in milliseconds.
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Once it is running the timeout cannot be changed and the WDT cannot be stopped either.
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Notes: On the esp32 the minimum timeout is 1 second. On the esp8266 a timeout
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cannot be specified, it is determined by the underlying system.
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Methods
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-------
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.. method:: wdt.feed()
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Feed the WDT to prevent it from resetting the system. The application
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should place this call in a sensible place ensuring that the WDT is
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only fed after verifying that everything is functioning correctly.
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