SOLVED!

I started going over the API docs in detail and found this:

The ESP32 UART controllers themselves do not support half-duplex communication as they cannot provide automatic control of the RTS pin connected to the RE/DE input of RS485 bus driver. However, half-duplex communication can be ...

Yes. There is no other circuitry that would pull or hold the TX_en line high.

TX goes directly to the isolator TX_in.
RX goes directly to the isolator RX_out.
TX_en goes directly to the isloator TX_en.


Most of the Message packets are properly bracketed by the TX_en (high while the packet is being ...

I am currently working with a PCBA that has a esp32s2 chip that uses a UART channel to control a VFD over a simple MODBUS interface. The module is set up to use UART serial that is connected to a RS485 Field Isolator with RX, TX, and TX_enable. When my module sends a packet, it sets TX_enable in ...

I was able to solve my issue by moving some stuff like .bss to the SPIRAM. I did also some changes in the menuconfig, I can post them in a few days, right now I am traveling.
But you don’t have SPIRAM, right? Well, maybe it will help somehow.


Yeah, this is kind of the path that I'm going down ...

E.g., this log message
"E (5056) McuCanBusChannel_Esp32: FAILED to Queue TWAI Message for Transmit!"
before the reboot, is that expected to be happening?
If not, I'd first go looking into where/why this happens, checking (error) return values to locate and identify the problem.


The TWAI error ...

Back with a bump and another plea for direction on this issue.

I've reached a build where I cannot get MQTT to not-crash with any of my admittedly hacky methods to mitigate the issue. I've mentioned them above, but did not clearly show what I was using to get around this issue. Prepare to be ...

I was just able to catch a hardlock. After I had a build that I knew would lock up, I tried to turn on the Task Watchdog, and see what I could see (and if it would still lock up):

I (4896) DEV_MQTT_Client: [DEV] MQTT_EVENT_BEFORE_CONNECT
I (4896) MCU_MQTT_Client_ESP32: MCU_MQTT_Client_ESP32 ...

I wasn't able to reproduce a mqtt hardlock in this configuration. It's nearly impossible to say "I want to reproduce it now", it's more of a "well, this build has the problem". Sometimes I can go hours without it showing up, and sometimes I can barely figure out a combination of tweaks to make it ...

I tried quickly to turn on the Task Watchdogs but that borked all of my TWAI/CAN stuff - TWAI driver quit working altogether.

I have a system based on an ESP32-S3 (N8) that uses Ethernet and the ESP-IDF MQTT client ) and I experience hardlocks in my system in a way I want to say is intermittent, but happen at the same place in my code in a deterministic manner.

PRIV_REQUIRES mqttclient
#include "mqtt_client.h"

The ...