# class WDT – watchdog timer

The WDT is used to restart the system when the application crashes and ends up into a non recoverable state. Once started it cannot be stopped or reconfigured in any way. After enabling, the application must “feed” the watchdog periodically to prevent it from expiring and resetting the system.

Example usage:

    from machine import WDT
    wdt = WDT(timeout=2000)  # enable it with a timeout of 2s
    wdt.feed()

## Constructors

class machine.WDT(id=0, timeout=5000)

  Create a WDT object and start it. The timeout must be given in milliseconds. Once it is running the timeout cannot be changed and the WDT cannot be stopped either.

  Notes: On the esp32 the minimum timeout is 1 second. On the esp8266 a timeout cannot be specified, it is determined by the underlying system. On rp2040 devices, the maximum timeout is 8388 ms.

## Methods

WDT.feed()

  Feed the WDT to prevent it from resetting the system. The application should place this call in a sensible place ensuring that the WDT is only fed after verifying that everything is functioning correctly.

Language and External Links

Language
  English
  中文

External links
  openmv.io
  forums.openmv.io
  github.com/openmv/openmv
  micropython.org
  forum.micropython.org
  github.com/micropython/micropython