Change UART baud rate NRF5340 w/ NRFConnect SDK

RE: Change UART baud rate NRF5340 w/ NRFConnect SDK

Simon — Wed, 03 Mar 2021 10:41:36 GMT

Have you checked what it's set to in the file <application>/<build>/zephyr/zephyr.dts? Search for uart1 an check what current-speed is equal to.

RE: Change UART baud rate NRF5340 w/ NRFConnect SDK

RJengr — Tue, 02 Mar 2021 17:00:43 GMT

Simon I changed the baud rate in the overlay file. However, it is still outputting a baud rate off 115.2k instead of a baud rate of 9600. See logic analyzer data and overlay file below.

/* SPDX-License-Identifier: Apache-2.0 */

&uart1 {
	compatible = "nordic,nrf-uarte";
        current-speed = <9600>; //<115200>;
	status = "okay";
	tx-pin = <33>;
	rx-pin = <32>;
};

RE: Change UART baud rate NRF5340 w/ NRFConnect SDK

Simon — Fri, 26 Feb 2021 10:59:27 GMT

I talked to the developer of the central_uart and peripheral_uart samples and the file prj.overlay does basically nothing. The file will be removed soon. Please add it to an overlay file in the following manner: <board name>.overlay. Check out Set devicetree overlays for more information about this.

Best regards,

Simon

RE: Change UART baud rate NRF5340 w/ NRFConnect SDK

RJengr — Thu, 25 Feb 2021 15:24:01 GMT

There is a prj.overlay file in the project already with a declaration of Uart0. is this the same?

RE: Change UART baud rate NRF5340 w/ NRFConnect SDK

Simon — Thu, 25 Feb 2021 15:08:51 GMT

Try adding an overlay file nrf5340dk_nrf5340_cpuapp.overlay (use the same board-name as the one you're bulding with) to your project with the following content:

&uart0 {
	status = "okay";
	current-speed = <new baud rate>; //<115200>;
};

That will overwrite the default speed set in <ncs location>\zephyr\boards\arm\nrf5340dk_nrf5340\nrf5340_cpuapp_common.dts

Best regards,

Simon