SPI does not work on nRF52832

[mamorudeta]

Hi

I put the MBN52832 (nRF52832) on my WSM-BL241-ADA-008DK to test the SPI (see the user guide here).

The sample "peripheral/spi" from SDK ver. 16.0 is used for the test. . However, the pin settings have been changed(sdk_config.h has not been changed).

The following is the source code.

#include "nrf_drv_spi.h"
#include "app_util_platform.h"
#include "nrf_gpio.h"
#include "nrf_delay.h"
#include "boards.h"
#include "app_error.h"
#include <string.h>
#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"

#define SPI_INSTANCE  0 /**< SPI instance index. */
static const nrf_drv_spi_t spi = NRF_DRV_SPI_INSTANCE(SPI_INSTANCE);  /**< SPI instance. */
static volatile bool spi_xfer_done;  /**< Flag used to indicate that SPI instance completed the transfer. */

#define TEST_STRING "Nordic"
static uint8_t       m_tx_buf[] = TEST_STRING;           /**< TX buffer. */
static uint8_t       m_rx_buf[sizeof(TEST_STRING) + 1];    /**< RX buffer. */
static const uint8_t m_length = sizeof(m_tx_buf);        /**< Transfer length. */

/**
 * @brief SPI user event handler.
 * @param event
 */
void spi_event_handler(nrf_drv_spi_evt_t const * p_event,
                       void *                    p_context)
{
    spi_xfer_done = true;
    NRF_LOG_INFO("Transfer completed.");
    if (m_rx_buf[0] != 0)
    {
        NRF_LOG_INFO(" Received:");
        NRF_LOG_HEXDUMP_INFO(m_rx_buf, strlen((const char *)m_rx_buf));
    }
}

int main(void)
{
    bsp_board_init(BSP_INIT_LEDS);

    APP_ERROR_CHECK(NRF_LOG_INIT(NULL));
    NRF_LOG_DEFAULT_BACKENDS_INIT();

    nrf_drv_spi_config_t spi_config = NRF_DRV_SPI_DEFAULT_CONFIG;
//    spi_config.ss_pin   = SPI_SS_PIN;
//    spi_config.miso_pin = SPI_MISO_PIN;
//    spi_config.mosi_pin = SPI_MOSI_PIN;
//    spi_config.sck_pin  = SPI_SCK_PIN;
    spi_config.ss_pin   = 29;
    spi_config.miso_pin = 2;
    spi_config.mosi_pin = 3;
    spi_config.sck_pin  = 4;
    APP_ERROR_CHECK(nrf_drv_spi_init(&spi, &spi_config, spi_event_handler, NULL));

    NRF_LOG_INFO("SPI example started.");

    while (1)
    {
        // Reset rx buffer and transfer done flag
        memset(m_rx_buf, 0, m_length);
        spi_xfer_done = false;

        APP_ERROR_CHECK(nrf_drv_spi_transfer(&spi, m_tx_buf, m_length, m_rx_buf, m_length));

        while (!spi_xfer_done)
        {
            __WFE();
        }

        NRF_LOG_FLUSH();

        bsp_board_led_invert(BSP_BOARD_LED_0);
        nrf_delay_ms(200);
    }
}

I ran it now and checked it on the oscilloscope, but it doesn't seem to respond to all the pins.

Is something missing in the settings?

Please help me out.

[Jørgen Holmefjord]

Hi,

but it doesn't seem to respond to all the pins

Can you be a bit more specific? Which pins are not showing any activity? A logic-trace of the bus will be great.

Best regards,
Jørgen 

[mamorudeta]

Hi, Jørgen Holmefjord

Thankyou for your reply.

I'm currently running the sample on one board with no connections to anywhere.

I set up the pins as follows.

    spi_config.ss_pin   = 29;
    spi_config.miso_pin = 2;
    spi_config.mosi_pin = 3;
    spi_config.sck_pin  = 4;

If I let the sample run, at least the oscilloscope will respond to the SCK and MOSI pins. I was thinking about it.

However, I didn't get any response, so I asked the question.

[Jørgen Holmefjord]

If it's not connected to anything, I would not expect any activity on MISO pin. The SS pin should go low before the transfer starts, and then high after the transfer is completed.

If SCK and MOSI pins toggle, it sounds like it is working as it should.