How to Configure GRBLHAL on Teensy 4.1 for Communication via Serial1

[noobianX]

First of all, I want to express my gratitude to the developers for the incredible effort you put into GRBLHAL. Your work has opened up amazing possibilities for many projects, and I truly appreciate it!

I have a specific question regarding GRBLHAL on the Teensy 4.1 (without a breakout board). How can I configure GRBLHAL to output reports on Serial1 instead of USB?
My goal is to control GRBLHAL using a Nextion display. Despite my best efforts and extensive attempts, I haven’t been able to achieve this setup.
I’ve successfully implemented similar examples on other microcontrollers that I found through Google, but I haven’t managed to make it work with the Teensy 4.1
If anyone could provide clear guidance or specific hints, I would be immensely grateful.

Thank you in advance for your time and support!

[noobianX]

Additionally, I tried adding the following line to my configuration:

#define USB_SERIAL_CDC 0

I assumed this would disable the USB CDC functionality and allow the reports to be output via the configured hal.stream functions, e.g.:

hal.stream.write_all(settings.status_report.machine_position ? "|MPos:" : "|WPos:");
hal.stream.write_all(get_axis_values(print_position));

However, according to my logic analyzer, there is no activity on any of the TX pins of the serial ports.

[noobianX]

Thank you, and I apologize for the potentially misleading wording in my previous message. To clarify, I have indeed set the relevant line in my_machine.h to 0. It looks like this:

#define USB_SERIAL_CDC 0 // 1 for Arduino class library and 2 for PJRC C library. Comment out or set to 0 to use UART communication.

Should this configuration already be enough for it to work?

[noobianX]

Would the command "hal.stream.write_all" be the correct way to output the report to the TX pin? Or would I need to edit report.c for this functionality?

[terjeio]

Should this configuration already be enough for it to work?

Possibly, I forgot to ask which board map you are using. I am using T41BB5X Pro.

Would the command "hal.stream.write_all" be the correct way to output the report to the TX pin?

Yes - to the TX pin and also other connected streams.

Or would I need to edit report.c for this functionality?

No.

Will the UART be the main communication channel or is that something else, e.g. a networked connection. If not the main channel you will have to enable a MPG mode so that the UART stream is registered for output on write_all()..

[noobianX]

At the moment, I have selected the T41BB5X Pro.
Currently, UART is intended to be the main communication channel, and no additional network connections are planned.
The only device communicating will be the Nextion display.

So, for now, I only want to communicate via UART.
Do I still need to activate an MPG mode in this case?
Thank you!

[terjeio]

So, for now, I only want to communicate via UART.
Do I still need to activate an MPG mode in this case?

Only uncomment #define USB_SERIAL_CDC then. I just verified that this works.