SDKv1.5.1 Blinky example with UART

RE: SDKv1.5.1 Blinky example with UART

Einar Thorsrud — Fri, 28 May 2021 12:19:18 GMT

Hi Sören,

You cannot use uart_tx() with CONFIG_UART_INTERRUPT_DRIVEN, as that is only supported by the newer CONFIG_UART_ASYNC_API. Note that CONFIG_UART_ASYNC_API is also interrupt driven so there are typically no reason to use the older API unless you want to be conservative.

RE: SDKv1.5.1 Blinky example with UART

SoerenBirth — Thu, 27 May 2021 13:18:14 GMT

Thanks Einar,

The key was just one line in the prj.conf file

after i deleted CONFIG_UART_INTERRUPT_DRIVEN it immediately worked!

The next question will be, how do i get the interrupt based transfer started.

Best regards

Sören

RE: SDKv1.5.1 Blinky example with UART

Einar Thorsrud — Thu, 27 May 2021 11:01:52 GMT

Hi,

I have attached a modified project that is working here. This works both on the DK and dongle. I tested with the default board file (zephyr\boards\arm\nrf52840dongle_nrf52840\nrf52840dongle_nrf52840.dts) with the Tx pin being P0.20, but using another pin should be no problem.

Code:

devzone.nordicsemi.com/.../0636.main.c

Config:

devzone.nordicsemi.com/.../8015.prj.conf

Logic analyzer plot:

RE: SDKv1.5.1 Blinky example with UART

SoerenBirth — Wed, 26 May 2021 06:42:46 GMT

devzone.nordicsemi.com/.../2437.blinky.rar

Hi Einar,

no i did not manage it. But here is my project.

Thank you,

Sören

RE: SDKv1.5.1 Blinky example with UART

Einar Thorsrud — Tue, 25 May 2021 15:17:04 GMT

Hi Sören,

I am sorry for the delay. Have you made any progress on this? If not, perhaps you can upload your project here so I can look at it and try to build it on my side?

[quote user="SoerenBirth"]But, why do i have to copy a file prj.overlay in the project with the same content as the zephyr.dts file???[/quote]

You do not, I did not spot that it was in there before. All should be good in this regard then (the prj.overlay is a overlay to the dts, in much the same as the prj.conf is a overlay for the Kconfig configuration, though it is unfortunately not well documented).

RE: SDKv1.5.1 Blinky example with UART

SoerenBirth — Fri, 21 May 2021 14:29:32 GMT

Okay,

after i copied the prj.overlay file in my project, it compiles no more...

nrfx_config.h is missing...

But, why do i have to copy a file prj.overlay in the project with the same content as the zephyr.dts file??? I think i don't have understoond this Config-File concept at all... and yes i have read the docs, multiple times!!!

Content of prj.overlay:
&uart0 {
compatible = "nordic,nrf-uarte";
};

Content of zephyr.dts:

...

uart0: uart@40002000 {
           reg = < 0x40002000 0x1000 >;
           interrupts = < 0x2 0x1 >;
           status = "okay";
           label = "UART_0";
           compatible = "nordic,nrf-uarte";
           current-speed = < 0x1c200 >;
           tx-pin = < 0x14 >;
           rx-pin = < 0x18 >;
           rts-pin = < 0x11 >;
           cts-pin = < 0x16 >;
       };

...

This makes no sense to me, sorry.

Sören

RE: SDKv1.5.1 Blinky example with UART

Einar Thorsrud — Fri, 21 May 2021 13:09:16 GMT

Hi Sören,

When you use CONFIG_UART_ASYNC_API=y you also need to specify uarte in the device tree, so referring to nrf\samples\bluetooth\peripheral_uart\ again you can look at prj.overlay (simply copy that to your project).

RE: SDKv1.5.1 Blinky example with UART

SoerenBirth — Thu, 20 May 2021 14:39:38 GMT

Hi Einar,

thanks,

1. and 2. are clear now.

After i changed the proj.conf to:

CONFIG_GPIO=y
CONFIG_UART_INTERRUPT_DRIVEN=y
CONFIG_SERIAL=y
CONFIG_UART_ASYNC_API=y

there is an address connected to the handler, but there is still now traffic on the pins (i used tx-pin = <0x14> and rx-pin = <0x18>). I've checked this with a logic analyser.

As i understand it, i only need the uart_tx() function to send something, am i right? Or is there another config that i have to set.

developer.nordicsemi.com/.../uart.html

==edit==

ret = uart_tx(uart_0_handle, &message, sizeof(message), SYS_FOREVER_MS );

returns -35 -> -ENOTSUP: If driver does not support getting current configuration.

Why the driver is not supported? Which driver is supported?

Thanks,

Sören

RE: SDKv1.5.1 Blinky example with UART

Einar Thorsrud — Thu, 20 May 2021 14:13:18 GMT

Hi Sören,

[quote user=""]1.) On which pins at the dongle, can i map the UART RX and TX pins?! Normally on a microcontroller i have a bunch of options, in the Nordic docs it looks like i can map them anywhere, can I? Precisely this configuration is feasible[/quote]

Any digital GPIO pin can be used for UART. See Pin assignments.

[quote user=""]2.) In the docs and even in the video the pins are numbered like "30", "31" and so on. But the in ref-maunal and the schematic there ist port number AND the pin number , e.g 0.12, 1.15, how do i address 1.15, when i want to used it as a UART pin in the config overlay file?[/quote]

The pin numbers you provide is x if using P0.x and y + 32 if using P1.y.

[quote user=""]3.) In the picture below, there is my code of the blinky example, including my attemps of using the UART via the zephyr-API. The Problem is, that the "device_get_binding" - function returns a NULL-pointer. I have no idea why. [/quote]

Have you enabled UART0 in prj.conf? You can refer to a sample that use UART, for instance nrf\samples\bluetooth\peripheral_uart\

Einar