watchdog – Watchdog Timer

The watchdog module provides support for a Watchdog Timer. This timer will reset the device if it hasn’t been fed after a specified amount of time. This is useful to ensure the board has not crashed or locked up. Note that on some platforms the watchdog timer cannot be disabled once it has been enabled.

The WatchDogTimer 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 microcontroller import watchdog as w
from watchdog import WatchDogMode
w.timeout=2.5 # Set a timeout of 2.5 seconds
w.mode = WatchDogMode.RAISE
w.feed()

Available on these boards
  • AITHinker ESP32-C3S_Kit
  • AITHinker ESP32-C3S_Kit_2M
  • ARAMCON Badge 2019
  • ARAMCON2 Badge
  • ATMegaZero ESP32-S2
  • Adafruit CLUE nRF52840 Express
  • Adafruit Camera
  • Adafruit Circuit Playground Bluefruit
  • Adafruit EdgeBadge
  • Adafruit Feather Bluefruit Sense
  • Adafruit Feather ESP32-S2 TFT
  • Adafruit Feather ESP32S2
  • Adafruit Feather ESP32S3 No PSRAM
  • Adafruit Feather M4 Express
  • Adafruit Feather RP2040
  • Adafruit Feather nRF52840 Express
  • Adafruit FunHouse
  • Adafruit Grand Central M4 Express
  • Adafruit Hallowing M4 Express
  • Adafruit ItsyBitsy M4 Express
  • Adafruit ItsyBitsy RP2040
  • Adafruit ItsyBitsy nRF52840 Express
  • Adafruit KB2040
  • Adafruit LED Glasses Driver nRF52840
  • Adafruit Macropad RP2040
  • Adafruit MagTag
  • Adafruit Matrix Portal M4
  • Adafruit Metro ESP32S2
  • Adafruit Metro M4 Airlift Lite
  • Adafruit Metro M4 Express
  • Adafruit Metro nRF52840 Express
  • Adafruit Monster M4SK
  • Adafruit PyGamer
  • Adafruit PyPortal
  • Adafruit PyPortal Pynt
  • Adafruit PyPortal Titano
  • Adafruit Pybadge
  • Adafruit QT Py ESP32-S3 no psram
  • Adafruit QT Py ESP32C3
  • Adafruit QT Py ESP32S2
  • Adafruit QT Py RP2040
  • Adafruit QT2040 Trinkey
  • Adafruit Trellis M4 Express
  • AloriumTech Evo M51
  • Arduino Nano 33 BLE
  • Arduino Nano RP2040 Connect
  • Artisense Reference Design RD00
  • AtelierDuMaker nRF52840 Breakout
  • BDMICRO VINA-D51
  • BLE-SS dev board Multi Sensor
  • BastBLE
  • BastWiFi
  • BlueMicro833
  • BlueMicro840
  • CP32-M4
  • Capable Robot Programmable USB Hub
  • Challenger NB RP2040 WiFi
  • Challenger RP2040 LTE
  • Challenger RP2040 WiFi
  • CircuitBrains Deluxe
  • CrumpS2
  • Cytron Maker Feather AIoT S3
  • Cytron Maker Nano RP2040
  • Cytron Maker Pi RP2040
  • DynOSSAT-EDU-OBC
  • ELECFREAKS PICO:ED
  • ESP 12k NodeMCU
  • ESP32-C3-DevKitM-1
  • ESP32-S2-DevKitC-1-N4
  • ESP32-S2-DevKitC-1-N4R2
  • ESP32-S3-Box-2.5
  • ESP32-S3-DevKitC-1-N8
  • ESP32-S3-DevKitC-1-N8R2
  • ESP32-S3-DevKitC-1-N8R8
  • ESP32-S3-DevKitM-1-N8
  • ESP32-S3-USB-OTG-N8
  • Electronut Labs Blip
  • Electronut Labs Papyr
  • EncoderPad RP2040
  • Feather ESP32S2 without PSRAM
  • FeatherS2
  • FeatherS2 Neo
  • FeatherS2 PreRelease
  • FeatherS3
  • Franzininho WIFI w/Wroom
  • Franzininho WIFI w/Wrover
  • Gravitech Cucumber M
  • Gravitech Cucumber MS
  • Gravitech Cucumber R
  • Gravitech Cucumber RS
  • HMI-DevKit-1.1
  • HexKyS2
  • HiiBot BlueFi
  • IkigaiSense Vita nRF52840
  • IoTs2
  • Kaluga 1
  • LILYGO TTGO T-01C3
  • LILYGO TTGO T-OI PLUS
  • LILYGO TTGO T8 ESP32-S2
  • LILYGO TTGO T8 ESP32-S2 w/Display
  • LoC BeR M4 base board
  • MDBT50Q-DB-40
  • MDBT50Q-RX Dongle
  • MORPHEANS MorphESP-240
  • MakerDiary nRF52840 MDK
  • MakerDiary nRF52840 MDK USB Dongle
  • Makerdiary M60 Keyboard
  • Makerdiary Pitaya Go
  • Makerdiary nRF52840 M.2 Developer Kit
  • Melopero Shake RP2040
  • MicroDev microC3
  • MicroDev microS2
  • Mini SAM M4
  • Oak Dev Tech BREAD2040
  • Oak Dev Tech Cast-Away RP2040
  • Oak Dev Tech PixelWing ESP32S2
  • Open Hardware Summit 2020 Badge
  • PCA10056 nRF52840-DK
  • PCA10059 nRF52840 Dongle
  • PCA10100 nRF52833 DK
  • Particle Argon
  • Particle Boron
  • Particle Xenon
  • PewPew M4
  • Pimoroni Badger 2040
  • Pimoroni Interstate 75
  • Pimoroni Keybow 2040
  • Pimoroni Motor 2040
  • Pimoroni PGA2040
  • Pimoroni Pico LiPo (16MB)
  • Pimoroni Pico LiPo (4MB)
  • Pimoroni PicoSystem
  • Pimoroni Plasma 2040
  • Pimoroni Servo 2040
  • Pimoroni Tiny 2040 (2MB)
  • Pimoroni Tiny 2040 (8MB)
  • ProS3
  • PyCubedv04
  • PyCubedv04-MRAM
  • PyCubedv05
  • PyCubedv05-MRAM
  • PyKey 18 Numpad
  • PyKey 44 Ergo
  • PyKey 60
  • PyKey 87 TKL
  • RP2.65-F
  • RP2040 Stamp
  • Raspberry Pi Pico
  • Robo HAT MM1 M4
  • S2Mini
  • S2Pico
  • SAM32v26
  • SSCI ISP1807 Dev Board
  • SSCI ISP1807 Micro Board
  • Saola 1 w/Wroom
  • Saola 1 w/Wrover
  • Seeed XIAO nRF52840 Sense
  • Seeeduino Wio Terminal
  • Seeeduino XIAO RP2040
  • Silicognition LLC M4-Shim
  • Simmel
  • SparkFun MicroMod RP2040 Processor
  • SparkFun MicroMod SAMD51 Processor
  • SparkFun MicroMod nRF52840 Processor
  • SparkFun Pro Micro RP2040
  • SparkFun Pro nRF52840 Mini
  • SparkFun Thing Plus - RP2040
  • SparkFun Thing Plus - SAMD51
  • Sprite_v2b
  • TG-Boards' Datalore IP M4
  • TG-Watch
  • TTGO T8 ESP32-S2-WROOM
  • Targett Module Clip w/Wroom
  • Targett Module Clip w/Wrover
  • Teknikio Bluebird
  • The Open Book Feather
  • TinkeringTech ScoutMakes Azul
  • TinyS2
  • TinyS3
  • UARTLogger II
  • W5100S-EVB-Pico
  • WarmBit BluePixel nRF52840
  • Waveshare RP2040-Zero
  • Winterbloom Sol
  • iLabs Challenger 840
  • micro:bit v2
  • nanoESP32-S2 w/Wrover
  • nanoESP32-S2 w/Wroom
  • nice!nano

exception watchdog.WatchDogTimeout

Bases: Exception

Exception raised when the watchdog timer is set to WatchDogMode.RAISE and expires.

Example:

import microcontroller
import watchdog
import time

wdt = microcontroller.watchdog
wdt.timeout = 5

while True:
    wdt.mode = watchdog.WatchDogMode.RAISE
    print("Starting loop -- should exit after five seconds")
    try:
        while True:
            time.sleep(10)  # Also works with pass
    except watchdog.WatchDogTimeout as e:
        print("Watchdog expired")
    except Exception as e:
        print("Other exception")

print("Exited loop")

Initialize self. See help(type(self)) for accurate signature.

class watchdog.WatchDogMode

run state of the watchdog timer

Enum-like class to define the run mode of the watchdog timer.

RAISE :WatchDogMode

Raise an exception when the WatchDogTimer expires.

RESET :WatchDogMode

Reset the system if the WatchDogTimer expires.

class watchdog.WatchDogTimer

Timer that is used to detect code lock ups and automatically reset the microcontroller when one is detected.

A lock up is detected when the watchdog hasn’t been fed after a given duration. So, make sure to call feed within the timeout.

Not currently dynamically supported. Access the sole instance through microcontroller.watchdog.

timeout :float

The maximum number of seconds that can elapse between calls to feed()

mode :WatchDogMode

The current operating mode of the WatchDogTimer watchdog.WatchDogMode.

Setting a WatchDogMode activates the WatchDog:

import microcontroller
import watchdog

w = microcontroller.watchdog
w.timeout = 5
w.mode = watchdog.WatchDogMode.RAISE

Once set, the WatchDogTimer will perform the specified action if the timer expires.

feed(self) None

Feed the watchdog timer. This must be called regularly, otherwise the timer will expire.

deinit(self) None

Stop the watchdog timer. This may raise an error if the watchdog timer cannot be disabled on this platform.