How to show log for firmware system part?

Hi,

I use Coolterm to monitor the usb port, it only shows the log message of user app part but cannot show system part. Does anyone know how to show the log ? Thanks!

The code like this:

LOG_DEBUG(INFO, "Hello!!");

Thanks,
Jack

I assume you have read the Logging section in the reference documents https://docs.particle.io/reference/device-os/firmware/photon/#logging ?

Before setup() you need to have this SerialLogHandler logHandler;

And then in the application you can log some messages with different logging levels

    Log.info("This is info message");
    Log.warn("This is warning message");
    Log.error("This is error message");

The System part does not automatically put out debug unless it has been built with such trace and you have compiled with the SystemLogHandler logHandler;

This specifically means building a monolithic debug image. Be aware that monolithic images don't support OTA so after debugging, you will need to reflash the system parts for the desired version of DeviceOS.