a Nrf52 function mapping to nrf51

[YASH]

Hi all,

I am working on interfacing an SD card as well as an OLED Display with my nrf51422 on SDK 12.2.0.

Although, both are on SPI and hence i need to configure them as multiple slaves using multiple master instances instead. I got a way on how to do it which is given here.[link text]:-

(devzone.nordicsemi.com/.../

Although this is done over nrf52, and i m getting a problem in the line:-

"volatile spi_control_block_t * my_setup = mw_spi_instance.drv_inst_idx;"

which says "mw_spi_instance" is undeclared.

Thus i want to know on how i should proceed further. Is there a parallel function in nrf51422 which can be supported replacing it?

Thank you in advance.

[Jørgen Holmefjord]

Hi,

I looked into this futher, and don't understand exactly how the solution is meant to work. I propose the following alternative, which require less changes to the files:

Declare the function nrf_drv_spi_switch_chips() in nrf_drv_spi.h, right below nrf_drv_spi_uninit():

void nrf_drv_spi_switch_chips( nrf_drv_spi_t const * const p_instance,
                               uint32_t                    chip_select );

Implement the function in nrf_drv_spi.c (below nrf_drv_spi_uninit()):

void nrf_drv_spi_switch_chips( nrf_drv_spi_t const * const p_instance,
                               uint32_t                    chip_select )
{
    spi_control_block_t * p_cb  = &m_cb[p_instance->drv_inst_idx];
    p_cb->ss_pin = chip_select;

    //A Slave select must be set as high before setting it as output,
    //because during connect it to the pin it causes glitches.
    nrf_gpio_pin_set(p_cb->ss_pin);
    nrf_gpio_cfg_output(p_cb->ss_pin);
    nrf_gpio_pin_set(p_cb->ss_pin);
}

You can now call the function with the SPI instance and SS pin as argument from any files including nrf_drv_spi.h (modified SPI master example from SDK 12.3.0):

static const nrf_drv_spi_t spi = NRF_DRV_SPI_INSTANCE(SPI_INSTANCE);  /**< SPI instance. */
#define SPI_SS_PIN_1 29
#define SPI_SS_PIN_2 30

...

int main(void)
{
    NRF_LOG_INFO("SPI example\r\n");

    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;
    APP_ERROR_CHECK(nrf_drv_spi_init(&spi, &spi_config, spi_event_handler));

    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_drv_spi_switch_chips(&spi, SPI_SS_PIN_2);

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

        while (!spi_xfer_done)
        {
            __WFE();
        }
        nrf_drv_spi_switch_chips(&spi, SPI_SS_PIN_1);
    }
}

Best regards,

Jørgen

[YASH]

Thank You so much. Sorry to bother you again, i am a beginner, but i am getting an error from here:-

// 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_drv_spi_switch_chips(&spi, SPI_SS_PIN_2);

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

    while (!spi_xfer_done)
    {
        __WFE();
    }
    nrf_drv_spi_switch_chips(&spi, SPI_SS_PIN_1);

it is saying these are undefined:- m_rx_buffer, rx_length, spi_xfer_done, m_tx_buf, m_length, m_rx_buf, m_length,

Please help me out.

Thank you in advance.

[Jørgen Holmefjord]

This was not meant as a full example. You need to merge it into the SPI example from the SDK. m_rx_buffer, rx_length, spi_xfer_done, m_tx_buf, m_length, m_rx_buf, amd m_length is defined there.

[YASH]

Thank You so much.

[Jørgen Holmefjord]

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