UART pin change

RE: UART pin change

Amanda Hsieh — Mon, 24 Aug 2020 13:36:15 GMT

Hi Aftab,

Are you using the NRF_LOG module and UART at the same time?

There are several similar cases on Devzone that might help you.

https://devzone.nordicsemi.com/f/nordic-q-a/46109/error-code-0x08-nrf_error_invalid_state-is-returned-by-uart_init/226458#226458

https://devzone.nordicsemi.com/f/nordic-q-a/37735/app_uart_fifo_init-returns-nrf_error_invalid_state-error-0x00000008

https://devzone.nordicsemi.com/f/nordic-q-a/19767/app_uart_fifo_init-crashes

If they still cannot help, please create a new for it. This issue is far away from the original issue.

-Amanda H.

RE: UART pin change

Aftab — Mon, 24 Aug 2020 11:24:44 GMT

I'm not using any development kit, we have our custom board. Basically we were using default pin 6/8 for UART logging. Then we had to assign these pins for some other peripheral. Now pin 45/46 are reserved for UART and no peripheral is connected to them. We just wanted to output the logs on these pins.

This is the error I get on terminal:

<error> app: ERROR 8 [NRF_ERROR_INVALID_STATE]

The error is on last line of the following code snippet:

static void uart_init(void)
{   
    uint32_t err_code;
    const app_uart_comm_params_t comm_params =
      {
          DTM_RX_PIN,
          DTM_TX_PIN,
          RTS_PIN_NUMBER,
          CTS_PIN_NUMBER,
          APP_UART_FLOW_CONTROL_DISABLED,
          false,
          DTM_BITRATE
      };

    APP_UART_FIFO_INIT(&comm_params,
                       UART_RX_BUF_SIZE,
                       UART_TX_BUF_SIZE,
                       uart_error_handle,
                       APP_IRQ_PRIORITY_LOWEST,
                       err_code);

    APP_ERROR_CHECK(err_code);
}

RE: UART pin change

Amanda Hsieh — Mon, 24 Aug 2020 11:13:16 GMT

Hi Aftab,

Are you using on nRF52840DK? If so, I don't think there are P0.45, P0.46 on nRF52840DK. You might consider other pins.

Not sure what is your code. Could you test with UART Example? Are you able to see data on the serial port before modifying the pin setting?

-Amanda H.

RE: UART pin change

Aftab — Mon, 24 Aug 2020 08:36:06 GMT

I added these lines to sdk_config.h, code compiled but no data on serial port:

#define APP_UART_ENABLED 1
#define UART_ENABLED 1
#define UART0_CONFIG_USE_EASY_DMA 1
#define APP_UART_DRIVER_INSTANCE 0
#define APP_FIFO_ENABLED 1

RE: UART pin change

Amanda Hsieh — Mon, 24 Aug 2020 07:42:08 GMT

Hi Aftab,

[quote user="Aftab"]

In the app_uart.c file it seems that I need to enable APP_UART, this pre-processor directive is disabling the whole file:

#if NRF_MODULE_ENABLED(APP_UART)

[/quote]

You need to enable the app_uart - UART driver in the sdk_config.h as

// <e> APP_UART_ENABLED - app_uart - UART driver
//==========================================================
#ifndef APP_UART_ENABLED
#define APP_UART_ENABLED 1
#endif

[quote user="Aftab"]why do we need to add this code, why not change some pin settings?[/quote]

You can just change the pin setting or rename the pin in the app_uart_comm_params_t as that case. It depends on your usage.

[quote user=""]I'm using SDK v16.0. I'm trying to change the default UART pins from 6,8 to 45,46. In the pca10056.h I have made following changes.[/quote]

Are you using on nRF52840DK? If so, I don't think there are P0.45, P0.46 on nRF52840DK. You might consider other pins.

-Amanda H.

RE: UART pin change

Aftab — Fri, 21 Aug 2020 14:30:40 GMT

I get this error after adding above files:

undefined reference to `app_uart_init'

In the app_uart.c file it seems that I need to enable APP_UART, this pre-processor directive is disabling the whole file:

#if NRF_MODULE_ENABLED(APP_UART)

BTW, why do we need to add this code, why not change some pin settings?

RE: UART pin change

Amanda Hsieh — Fri, 21 Aug 2020 13:13:04 GMT

Hi Aftab,

[quote user=""]But it throws error: Cannot find definition of app_uart_comm_params_t[/quote]

You have to include app_uart.h and app_uart.c under nRF5_SDK\components\libraries\uart. See Including header files and Adding source files.

-Amanda H.