WDT Watchdog Tutorial#
What is WDT?#
WDT (Watchdog Timer) is a defensive mechanism for system stability, ensuring that when a program encounters an exception (such as an infinite loop or freeze), the system can automatically restart to resume operation.
Typical uses include:
Preventing embedded devices from being stuck for long periods
Ensuring programs respond in a timely manner in mission-critical tasks
A core component of the system self-recovery mechanism
K230 WDT Features#
Feature |
Description |
|---|---|
Supported channels |
Built-in 2 WDT channels (WDT0 / WDT1) |
Minimum timeout |
Second-level precision, timeout is usually 1 second or more |
Reset mechanism |
Automatically triggers system reset upon timeout |
Manual feeding |
Call the |
Application Example: Basic Watchdog Test#
The following example sets a 3-second timeout through WDT1, and simulates a “feed the dog” operation in the program to prevent the system from restarting.
Example Code#
import time
from machine import WDT
# ========== Initialize WDT1 ==========
wdt1 = WDT(1, 3) # Channel 1, timeout 3 seconds
# ========== Wait 2 seconds ==========
time.sleep(2)
# ========== Feed the dog operation ==========
wdt1.feed() # Reset the watchdog counter to avoid triggering a system reset
# ========== Wait another 2 seconds ==========
time.sleep(2)
# If feed() is not called again, the system will automatically restart after 3 seconds
Interface Description#
Method Name |
Description |
|---|---|
|
Create a watchdog object, with parameters being the channel number and timeout duration (in seconds) |
|
Feed the watchdog operation, resets the countdown counter |
Usage Recommendations#
Scenario |
Recommended Operation |
|---|---|
System task deadlock prevention |
Call |
Serial/Network stall detection |
Feed the watchdog only after successfully receiving data |
Multi-threaded applications |
Use a message queue to notify the main thread to feed the watchdog periodically |
Frequently Asked Questions and Troubleshooting#
Issue |
Cause and Solution |
|---|---|
Program auto-restarts after running for a while |
The watchdog was not fed, and the timeout reset has been triggered |
Still restarts after feeding the watchdog |
Feed frequency is lower than the timeout, or the call location is not in the main loop |
Want to disable the watchdog |
K230 currently has no disable interface; it is recommended to adapt and avoid it at the logic level |