"APP_UART_COMMUNICATION_ERROR" for nRF52832

[Milky]

Hi guys! I'm a beginner of nRF52832, and I met an issue as the topic said.

When I init the UART module, it will cause an "APP_UART_COMMUNICATION_ERROR", and the error code is 4 "No Memory For Operation".

#define UART_TX_BUF_SIZE    256
#define UART_RX_BUF_SIZE    256

void uart_config(void)
{
    uint32_t err_code = NRF_SUCCESS;
    
    const app_uart_comm_params_t comm_params = {
        RX_PIN_NUMBER,  //8
        TX_PIN_NUMBER,  //6
        RTS_PIN_NUMBER, //7
        CTS_PIN_NUMBER, //5
        APP_UART_FLOW_CONTROL_DISABLED,
        false,
        NRF_UART_BAUDRATE_115200
    };
    
    APP_UART_FIFO_INIT(&comm_params,
                        UART_RX_BUF_SIZE,   //256
                        UART_TX_BUF_SIZE,   //256
                        uart_error_handle,
                        APP_IRQ_PRIORITY_LOWEST,
                        err_code);
    
    APP_ERROR_CHECK(err_code);
}

What can I do to fix it?

BTW, I'm using my own board, and coding on Keil uVision 5, and the RX_PIN has already set to PULLUP.

If you need more info, please let me know, thanks!

[Milky]

One more thing to know, my SW now only contains 'uart_config()', and the error still comes up.

[ovrebekk]

Hi

You mean to say you are not trying to send or receive anything?

Is there any chance the RX pin could be low when you're enabling the UART?

Best regards
Torbjørn

[Milky]

1、Yes, I only initialize the UART module, and do nothing else;

2、I've tried to monitor the RX pin by using the logic analyzer before, and it didn't receive any low signal.

[ovrebekk]

Hi

Are you using a standard nRF52DK, or some other nRF52832 based board?

Any chance you could share your code with me so I can have a look at it?

I can make the case private in case you don't want to share your code in a public case. 

Best regards
Torbjørn