ESP32 Forum

Hello ESP Team,

Environment Details:
Board: ESP32-WROOM32 module soldered on an custom board.
ESP-IDF Version 3.3.1
MSYS32 Environment with python 2.7
IDE: Eclipse.

Problem Description:
I have implemented a logic to read data from a UART device and send it to a cloud service. ESP32 is connected to a serial GSM modem SIM900C and I use PPP to communicate with the cloud server. I have aroud 3-4 FreeRTOS tasks running to manage my stuff.
The problem I face is, when I debug the ESP board using JTAG I feel my logic to be working fine but when I see the ESP32's log output on UART I see the below message popping up several times. Most of the time I don't see any issues with this but occassionally I see the controller getting restarted. I feel I need to take some care regarding the watchdog timer but I am unable to find a solid documentation describing the WDT task's behavior and implementation in ESP-IDF.

Below is the message which I see frequently:
E (6104) task_wdt: Task watchdog got triggered. The following tasks did not reset the watchdog in time:
E (6104) task_wdt: - IDLE1 (CPU 1)
E (6104) task_wdt: Tasks currently running:
E (6104) task_wdt: CPU 0: IDLE0
E (6104) task_wdt: CPU 1: CORE

Can anyone describe what does it mean and where can I find the documentation related to the WDT task?

Note: I am not using the WiFi for internet access and my code does not use any WiFi related APIs. I doubt that I may have to disable the protocol processing CPU or free it from handling WiFi tasks or unsubscribe the protocol CPU from sending WDT events.

In general, this means the idle tasks (which need to run in FreeRTOS for some housekeeping tasks) haven't all been able to run for a few seconds. This normally indicates that you have one task (in your case, CORE) that is hogging all CPU power and not yielding to other, lower-priority tasks. This can happen when e.g. you use a spinlock (while (variable==0) instead of FreeRTOS blocking constructs like muxes and semaphores.

Thanks for the reply.
I noticed that the CORE task was starving other tasks.
It solved my issue.
But can you provide more information regarding the WDT implementation.
What is the WDT interval ?

Hi mmurty,

The docs for the WDT features can be found here:
https://docs.espressif.com/projects/esp ... /wdts.html

The config item for the default Task WDT time period isn't mentioned on that page (will fix), but it's found alongside the other WDT config items which are mentioned:
https://docs.espressif.com/projects/esp ... -timeout-s