Problem using UART using NCS 2.9.0

RE: Problem using UART using NCS 2.9.0

icedfluid — Wed, 23 Apr 2025 16:48:35 GMT

To make work UART correctly on SDK >= 2.8.0, you should add this to your prj.conf :

# (to make uart work on sdk >= 2.8.0)
CONFIG_UART_NRFX_UARTE_LEGACY_SHIM=n

related post (I guess) :
devzone.nordicsemi.com/.../511530

RE: Problem using UART using NCS 2.9.0

d_7 — Tue, 15 Apr 2025 17:43:17 GMT

Hello,

The chip is

N52833
Q1AAB0
2116AA

RE: Problem using UART using NCS 2.9.0

Kazi Afroza Sultana — Tue, 15 Apr 2025 16:42:24 GMT

Hello,

The reason this worked in NCS 2.6.1 but not in 2.9.0 might be related to changes in how the interface MCU interacts with these pins.

Which version of nRF52833DK you are using?

It could be a side effect on the new boards that use the nRF5340 as the interface chip, versus older boards that used third-party IC for this. The solution is to use different GPIO pins that are not used by the interface chip as I said before as well.

RE: Problem using UART using NCS 2.9.0

d_7 — Mon, 14 Apr 2025 13:34:07 GMT

Hello,

Using the default pins, it works. But I need to change to the ones mentioned above.

Why in ncs 2.6.1 it works with my pins and in ncs 2.9.0 it doesn't?

RE: Problem using UART using NCS 2.9.0

Kazi Afroza Sultana — Tue, 08 Apr 2025 13:03:25 GMT

Hello,

Pins P0.06 and P0.08 are specifically used by the interface MCU for UART communication. source: Virtual serial port

When you're trying to use these pins for external communication (to your USB serial converter), they're already being used by the interface MCU for the virtual COM port. I guess for this reason, it does not work from PC B to PC A through external USB serial converter.

Can try to change your UART pins to avoid using P0.06 and P0.08, which are already used by the interface MCU?

RE: Problem using UART using NCS 2.9.0

d_7 — Tue, 01 Apr 2025 14:19:55 GMT

Hello,

These are my project files:

devzone.nordicsemi.com/.../7510.main.c devzone.nordicsemi.com/.../3301.prj.conf devzone.nordicsemi.com/.../4466.nrf52833dk_5F00_nrf52833.overlay

Regarding the output, I don't have nothing that can help. But I can try to explain the problem better.

I have a USB serial converter connected to a PC with hterm (PC B). And a nRF52833 DK connected to other PC with nRF Connec for VS Code (PC A).

Using the default UART pins of the nRF52833 DK, I send “test1” via VCOM0 from PC A to PC B and the data appears in PC B hterm. Then, for example, I send “test1_ans” via PC B hterm and this data appears on PC A.

When I change the pins to those described above, I send “test1” via VCOM0 from PC A to PC B and the data appears in PC B hterm. However, when I send “test1_ans” via PC B hterm, this data does not appear on PC A.

Thank you

RE: Problem using UART using NCS 2.9.0

Kazi Afroza Sultana — Tue, 01 Apr 2025 13:06:41 GMT

Hello,

The default pin number of MOSI is P0.30 in the default pincontrol (nrf52833dk_nrf52820-pinctrl.dtsi) file (C:\ncs\v2.9.0\zephyr\boards\nordic\nrf52833dk\nrf52833dk_nrf52820-pinctrl.dtsi)).

'I disabled spi, i2c, adc, leds and buttons to make sure that there were no conflicts between pins.''

Can you share the board file of your application with me then I can see if disabling the peripheral is ok or not?

''However, when I switch to the pins I'm using in the main project, communication only works in one direction (nRF -> device), i.e. there's no more communication (nrf <- device).

Do you have any output log that you can share with us?

Thanks.

Kazi