ESP32 Forum

Is it possible to attach to a running ESP32 DevKitC on Linux, without resetting the ESP32?

Use case:
I use "make flash monitor" and all looks good. I leave the ESP32 running for a day or so and accidentally terminated the monitor. This leaves the ESP32 unaffected which is good. One day later, I would like to see what is currently printed on the serial console (there is continuous logging).

Using 'make monitor' or 'make simple_monitor' does not work: It always resets the ESP32 before getting any log messages. I would like to see the serial output without resetting the ESP32.

This is on Linux. Or is this impossible since RTS is used to reset the device?

Cheers,
Johannes

The "make monitor" does appear to perform an ESP32 reset ... however if your ESP32 is running, executing a local serial terminal client such as putty or screen connects to the serial port without resetting and you will start to immediately see your output without a reset.

Many thanks! Just attaching screen works! Why di dI not just try this? I should have just tried it. I was confused in thinking that the 'make monitor' and 'make simple_monitor' targets do some other required setup to get to the serial console, but just attaching a serial terminal works just like that. I should have just tried it out!

I am using this command line on Linux in my setup:
screen /dev/ttyUSB0 115200

Anyway, 'make monitor' (and make 'simple_monitor') solve the problem to get the very first messages after a restart, which is otherwise hard to get. I now see the point of them.

Cheers,
Johannes