Hi Nordic
SInce this is my first time to develop Nordic chip and implement SPIS driver, Therefore i am not so familiar with Nordic API. I would really appreciate it if someone would give me hint regarding this question.
Question: How can I response different data (Tx buffer) when I receive data (Rx buffer) from SPI Master ?
According the description from Nordic web. After spis_event_handler() is called, the transfer has been completed. It means I need to set Tx buffer before I get spis_event_handler() event.
In this behavior, How can I response different data (Tx buffer) when I receive data (Rx buffer) from SPI Master ?
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The callback handler function will be called after every successful buffer setup and every completed transfer. New buffers must be set by calling nrf_drv_spis_buffers_set after every finished transaction. Otherwise, the transaction is ignored, and the default character is clocked out.
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Here is the sample which i am reference now.
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* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* 4. This software, with or without modification, must only be used with a
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*
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*/
#include "sdk_config.h"
#include "nrf_drv_spis.h"
#include "nrf_gpio.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 SPIS_INSTANCE 1 /**< SPIS instance index. */
static const nrf_drv_spis_t spis = NRF_DRV_SPIS_INSTANCE(SPIS_INSTANCE);/**< SPIS instance. */
#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. */
static volatile bool spis_xfer_done; /**< Flag used to indicate that SPIS instance completed the transfer. */
/**
* @brief SPIS user event handler.
*
* @param event
*/
void spis_event_handler(nrf_drv_spis_event_t event)
{
if (event.evt_type == NRF_DRV_SPIS_XFER_DONE)
{
spis_xfer_done = true;
NRF_LOG_INFO(" Transfer completed. Received: %s",(uint32_t)m_rx_buf);
}
}
int main(void)
{
// Enable the constant latency sub power mode to minimize the time it takes
// for the SPIS peripheral to become active after the CSN line is asserted
// (when the CPU is in sleep mode).
NRF_POWER->TASKS_CONSTLAT = 1;
bsp_board_init(BSP_INIT_LEDS);
APP_ERROR_CHECK(NRF_LOG_INIT(NULL));
NRF_LOG_DEFAULT_BACKENDS_INIT();
NRF_LOG_INFO("SPIS example");
nrf_drv_spis_config_t spis_config = NRF_DRV_SPIS_DEFAULT_CONFIG;
spis_config.csn_pin = APP_SPIS_CS_PIN;
spis_config.miso_pin = APP_SPIS_MISO_PIN;
spis_config.mosi_pin = APP_SPIS_MOSI_PIN;
spis_config.sck_pin = APP_SPIS_SCK_PIN;
APP_ERROR_CHECK(nrf_drv_spis_init(&spis, &spis_config, spis_event_handler));
while (1)
{
memset(m_rx_buf, 0, m_length);
spis_xfer_done = false;
APP_ERROR_CHECK(nrf_drv_spis_buffers_set(&spis, m_tx_buf, m_length, m_rx_buf, m_length));
while (!spis_xfer_done)
{
__WFE();
}
NRF_LOG_FLUSH();
bsp_board_led_invert(BSP_BOARD_LED_0);
}
}
