No output to UART console when CONFIG_BT=y

[jchan12345]

There is no output to UART console when I set CONFIG_BT=y in prj.conf

peripheral_lbs sample project in ncs V2.0.2 can't printk anything.  

[Hieu]

Hi,

Unfortunately I cannot reproduce your issue.
I just now tried a brand new application based on the NCS v2.0.2 peripheral_lbs example on both the nRF52DK and the nRF5340DK, and for both printk() worked and I got data on a Serial Port.
I really don't think CONFIG_BT=y would break UART console, that would really not make sense.

Are you developing on a Development Kit or on your custom board?

By the way, as you requested, the prj.conf used to test:

#
# Copyright (c) 2018 Nordic Semiconductor
#
# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
#
CONFIG_NCS_SAMPLES_DEFAULTS=y

CONFIG_BT=y
CONFIG_BT_PERIPHERAL=y
CONFIG_BT_DEVICE_NAME="Nordic_LBS"

# Enable the LBS service
CONFIG_BT_LBS=y
CONFIG_BT_LBS_POLL_BUTTON=y
CONFIG_DK_LIBRARY=y

CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=2048

Best regards,
Hieu

[jchan12345]

Hello Hieu, 

Thanks for your quick response.  I have one more request.  Would you use the nrf5340dk_nrf5340_cpuapp.overlay    file to disable to UART console and see if you can still receive output.?  My problem seems to be complicated.  The UART on nRF5340DK always work even if I intentionally disable the UART or assign different TX and RX pins.   I am trying to make sure the overlay file can change the behavior first, then I will make correct adjustment on my own custom board. 

I have more problem on my custom board, but one thing at a time.  I want to get the UART working in different configuration/overlay first.

Thanks again.

My own. nrf5340dk_nrf5340_cpuapp.overlay. for a different custom board, but nRF5340DK is unexpectly working fine with it, so something is wrong

I may have mistakes in the overlay file

&uart0 {
    //status = "okay";
    status = "disabled";
	label = "UART_0";
	current-speed = <115200>;		// 115200
    pinctrl-0 = <&uart0_default_alt>;
    pinctrl-1 = <&uart0_sleep_alt>;
    pinctrl-names = "default", "sleep";
};


&pinctrl {
    uart0_default_alt: uart0_default_alt {
        group1 {
            psels = <NRF_PSEL(UART_TX, 1, 1)>;		// P1.1 is TX
        };
        group2 {
            psels = <NRF_PSEL(UART_RX, 0, 29)>;		// P0.29 is RX
            bias-pull-up;
        };
    };
    uart0_sleep_alt: uart0_sleep_alt {
        group1 {
            psels = <NRF_PSEL(UART_TX, 1, 1)>,		// P1.1 is TX
                    <NRF_PSEL(UART_RX, 0, 29)>;		// P0.29 is RX
            low-power-enable;
        };
    };
};

[jchan12345]

Hello Hieu,

Here is the result of test according to your instructions.

0. Run a fresh run with an empty overlay file

"You should observed both bootloader and application logging on one port.
That is VCOM2."

I saw UART output from AppCore and NetCore

[jchan12345]

1. UART0 with TX on P1.01, RX on P1.00 (VCOM0/UART1 ports). Not disabling GPIO forwarde

You should observed only bootloader logging on a different COM port.

That is VCOM0.

I got same output as case 0.

[jchan12345]

2. UART0 with TX on P1.01, RX on P1.00 (VCOM0/UART1 ports). Disabling GPIO forwarder.

You should observed both bootloader and application logging on VCOM0

I did not the uart output from the NetCore now, so I think the UART output from NetCore is not forwarded

[jchan12345]

3. UART0 with TX on P1.01, RX on P0.29 (your configuration). Disabling GPIO forwarder.

You should observed both bootloader and application logging on VCOM0.

Now I got the AppCore UART output on the right terminal.  Disable the GPIO forwarder is the secret.

[jchan12345]

4. UART0 with TX on P1.01, RX on P0.29 (your configuration). NOT disabling GPIO forwarder.

You should observed only bootloader logging on VCOM0.

Now I have the UART output of the NetCore only.