Send multiple MOSI signal to SPI and received it on m_rx_buf?

[FormerMember]

Hello!

Does anyone know how can we send the multiple uint8_t MOSI signal to SPI and received the result on m_rx_buf?

Trying to send multiple bytes to "m_tx_buf":

#define SPI_INSTANCE  0 /**< SPI instance index. */  //line 24
static const nrf_drv_spi_t spi = NRF_DRV_SPI_INSTANCE(SPI_INSTANCE);  /**< SPI instance. */ //line 25
static volatile bool spi_xfer_done;  /**< Flag used to indicate that SPI instance completed the transfer. */
static uint8_t       m_tx_buf[] = {0x18,0x00};           /**< TX buffer. */ //line 29
static uint8_t       m_rx_buf[sizeof(m_tx_buf) + 1];    /**< RX buffer. */ //line 30
static const uint8_t m_length = sizeof(m_tx_buf);        /**< Transfer length. */ //line 31

The main code in 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));
APP_ERROR_CHECK(nrf_drv_spi_transfer(&spi, m_tx_buf, m_length, m_rx_buf, m_length)); //line 69

        while (!spi_xfer_done)
        {
            __WFE();
        }

        NRF_LOG_FLUSH();

        LEDS_INVERT(BSP_LED_0_MASK);
        nrf_delay_ms(200);

[Ole Bauck]

If you want to receive 3 bytes, the last parameter (rx_buffer_length) in nrf_drv_spi_transfer(..) should be 3. Other than that it looks fine, do you experience any problems with this code?

[FormerMember]

Can I send multiple byte to MOSI like this?

static uint8_t       m_tx_buf[] = {0x20, 0x00, 0x2C,0x00};           /**< TX buffer. *

[Ole Bauck]

Yes, just pass this array as p_tx_buffer parameter and the length as the tx_buffer_length parameter.