UARTE.h

Question

I was at 1st trying to use libuarte and it worked. However, talking to Edvin has convinced me to use something else as it is very resource heavy and I do not particularly need libuarte. So, I moved to uarte. I found no coding example of uarte online or in the SDK file. However, I found a description of it in the datasheet and I analyzed the uarte.h file and understood the library as much as I could.

UARTE description that I used can be found here: infocenter.nordicsemi.com/index.jsp

Things I need to achieve:

1) Send ASCII transmission of "0GYTP/r" to a motion controller

2) Recieve the corresponding response of the transmission from a motion controller

Here is the code, I feel I covered everything and still it does not work. I do not get the output which is "MCDC3002-RS/r/n". I know the error is not in my device setup because I receive a response with libuarte.

Here is my code please help.

#include <app_error.h>
#include <app_util_platform.h>
#include <nrf.h>
#include <nrf_gpio.h>
#include <nrf_gpiote.h>
#include <nrf_log.h>
#include <nrf_log_ctrl.h>
#include <nrf_log_default_backends.h>
#include <nrf_nvic.h>
#include <nrf_rtc.h>
#include <nrf_soc.h>
#include <nrf_uarte.h>
#include <nrfx.h>
#include <nrfx_gpiote.h>
#include <nrfx_ppi.h>
#include <nrfx_pwm.h>
#include <nrfx_saadc.h>
#include <nrfx_spim.h>
#include <nrfx_twi.h>

#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <string.h>

#define MCDC_comms NRF_UARTE0
#define RX_BUF_LEN 32
#define Tx_pin 30
#define Rx_pin 31

void memory_barrier() {}

static void uart_validate_MCDC() {
    assert(!nrf_uarte_event_check(MCDC_comms, NRF_UARTE_EVENT_ERROR));
}

void uart_init_MCDC() {
    nrf_uarte_event_clear(MCDC_comms, NRF_UARTE_EVENT_ERROR);
    nrf_uarte_baudrate_set(MCDC_comms, NRF_UARTE_BAUDRATE_9600);
    nrf_uarte_configure(MCDC_comms, NRF_UARTE_PARITY_EXCLUDED, NRF_UARTE_HWFC_DISABLED);
    nrf_uarte_disable(MCDC_comms);
    uart_validate_MCDC();
}

static bool active_rx_has_cr(const char *rx_buf, size_t rx_len) {
    memory_barrier();
    for (size_t i = 0; i < rx_len; ++i) {
        if (rx_buf[i] == '\n') { 
            return true;
        }
    }
    return false;
}

size_t uart_MCDC_txrx(const void *tx_buf, size_t tx_len,void *rx_buf, size_t rx_len) {
    assert(tx_len < 256);
    assert(rx_len < 256);
    
    nrf_uarte_txrx_pins_set(MCDC_comms, Tx_pin, Rx_pin);
    uart_validate_MCDC();
    nrf_uarte_enable(MCDC_comms);
    
    memset(rx_buf, 0, rx_len);
    
    nrf_uarte_tx_buffer_set(MCDC_comms, tx_buf, tx_len);
    nrf_uarte_event_clear(MCDC_comms, NRF_UARTE_EVENT_ENDTX);
    nrf_uarte_rx_buffer_set(MCDC_comms, rx_buf, rx_len);
    nrf_uarte_event_clear(MCDC_comms, NRF_UARTE_EVENT_ENDRX);
    nrf_uarte_task_trigger(MCDC_comms, NRF_UARTE_TASK_STARTTX);
    nrf_uarte_task_trigger(MCDC_comms, NRF_UARTE_TASK_STARTRX);
    uart_validate_MCDC();

    while (!nrf_uarte_event_check(MCDC_comms, NRF_UARTE_EVENT_ENDTX));
    while (!active_rx_has_cr(rx_buf, rx_len));


    nrf_uarte_task_trigger(MCDC_comms, NRF_UARTE_TASK_STOPRX);    
    while (!nrf_uarte_event_check(MCDC_comms, NRF_UARTE_EVENT_ENDRX));

    size_t n_rx = nrf_uarte_rx_amount_get(MCDC_comms);
    nrf_uarte_disable(MCDC_comms);
    return n_rx;
}

int main() {

    char tx_buf[] = "0GTYP\r";
    char rx_buf[RX_BUF_LEN] = {};

    uart_init_MCDC();
    uart_MCDC_txrx(tx_buf, strlen(tx_buf), rx_buf, RX_BUF_LEN);
    while(1) {
      break;
    }
    return 0;
}

UARTE.h

Top Replies