SPI CODE¶

Component Architecture¶

- driver
    - spi
        - include
            - spi.h
        - spi.c
        - CMakeLists.txt

driver/spi/CMakeLists.txt¶

set(src_dirs
    .
)

set(include_dirs
    include
)

set(requires
    driver
)

idf_component_register(SRC_DIRS ${src_dirs} INCLUDE_DIRS ${include_dirs} REQUIRES ${requires})

Note

Note that in the drivers, we used spi and gpio related functions from the builtin driver library, therefore, we need to indicate these dependencies in the CMakeLists.txt file by adding driver to the REQUIRES field.

spi.h¶

/**
 * @file spi.h
 * @author SHUAIWEN CUI (SHUAIWEN001@e.ntu.edu.sg)
 * @brief
 * @version 1.0
 * @date 2024-11-18
 * @ref Alientek SPI driver
 * @copyright Copyright (c) 2024
 *
 */

#ifndef __SPI_H__
#define __SPI_H__

/* Dependencies */
#include <string.h>
#include "esp_log.h"
#include "driver/spi_master.h"
#include "driver/gpio.h"

/* GPIO Definitions */
#define SPI2_MOSI_GPIO_PIN GPIO_NUM_11 /* SPI2_MOSI */
#define SPI2_CLK_GPIO_PIN GPIO_NUM_12  /* SPI2_CLK */
#define SPI2_MISO_GPIO_PIN GPIO_NUM_13 /* SPI2_MISO */

/* Function Prototypes */

/**
 * @brief       Initialize SPI
 * @param       None
 * @retval      None
 */
void spi2_init(void);

/**
 * @brief       Send command via SPI
 * @param       handle : SPI handle
 * @param       cmd    : Command to send
 * @retval      None
 */
void spi2_write_cmd(spi_device_handle_t handle, uint8_t cmd);

/**
 * @brief       Send data via SPI
 * @param       handle : SPI handle
 * @param       data   : Data to send
 * @param       len    : Length of data to send
 * @retval      None
 */
void spi2_write_data(spi_device_handle_t handle, const uint8_t *data, int len);

/**
 * @brief       Process data via SPI
 * @param       handle       : SPI handle
 * @param       data         : Data to send
 * @retval      t.rx_data[0] : Received data
 */
uint8_t spi2_transfer_byte(spi_device_handle_t handle, uint8_t byte);

#endif

spi.c¶

/**
 * @file spi.c
 * @author 
 * @brief 
 * @version 1.0
 * @date 2024-11-18
 * @ref Alientek SPI driver
 * 
 */

 #include "spi.h"

 /**
  * @brief       Initialize SPI
  * @param       None
  * @retval      None
  */
 void spi2_init(void)
 {
     esp_err_t ret = 0;
     spi_bus_config_t spi_bus_conf = {0};

     /* SPI bus configuration */
     spi_bus_conf.miso_io_num = SPI2_MISO_GPIO_PIN;                               /* SPI_MISO pin */
     spi_bus_conf.mosi_io_num = SPI2_MOSI_GPIO_PIN;                               /* SPI_MOSI pin */
     spi_bus_conf.sclk_io_num = SPI2_CLK_GPIO_PIN;                                /* SPI_SCLK pin */
     spi_bus_conf.quadwp_io_num = -1;                                            /* SPI write protection signal pin, not enabled */
     spi_bus_conf.quadhd_io_num = -1;                                            /* SPI hold signal pin, not enabled */
     spi_bus_conf.max_transfer_sz = 160 * 80 * 2;                                /* Configure maximum transfer size in bytes */

     /* Initialize SPI bus */
     ret = spi_bus_initialize(SPI2_HOST, &spi_bus_conf, SPI_DMA_CH_AUTO);        /* SPI bus initialization */
     ESP_ERROR_CHECK(ret);                                                       /* Check parameter values */
 }

 /**
  * @brief       Send command via SPI
  * @param       handle : SPI handle
  * @param       cmd    : Command to send
  * @retval      None
  */
 void spi2_write_cmd(spi_device_handle_t handle, uint8_t cmd)
 {
     esp_err_t ret;
     spi_transaction_t t = {0};

     t.length = 8;                                       /* Number of bits to transmit (1 byte = 8 bits) */
     t.tx_buffer = &cmd;                                 /* Fill the command */
     ret = spi_device_polling_transmit(handle, &t);      /* Start transmission */
     ESP_ERROR_CHECK(ret);                               /* Usually no issues */
 }

 /**
  * @brief       Send data via SPI
  * @param       handle : SPI handle
  * @param       data   : Data to send
  * @param       len    : Length of data to send
  * @retval      None
  */
 void spi2_write_data(spi_device_handle_t handle, const uint8_t *data, int len)
 {
     esp_err_t ret;
     spi_transaction_t t = {0};

     if (len == 0)
     {
         return;                                     /* No data to transmit if length is 0 */
     }

     t.length = len * 8;                             /* Number of bits to transmit (1 byte = 8 bits) */
     t.tx_buffer = data;                             /* Fill the data */
     ret = spi_device_polling_transmit(handle, &t);  /* Start transmission */
     ESP_ERROR_CHECK(ret);                           /* Usually no issues */
 }

 /**
  * @brief       Process data via SPI
  * @param       handle       : SPI handle
  * @param       data         : Data to send
  * @retval      t.rx_data[0] : Received data
  */
 uint8_t spi2_transfer_byte(spi_device_handle_t handle, uint8_t data)
 {
     spi_transaction_t t;

     memset(&t, 0, sizeof(t));

     t.flags = SPI_TRANS_USE_TXDATA | SPI_TRANS_USE_RXDATA;
     t.length = 8;
     t.tx_data[0] = data;
     spi_device_transmit(handle, &t);

     return t.rx_data[0];
 }

main.c¶

refer to LCD code

Note

Above are the codes to setup SPI2 on ESP32-S3. If other SPI peripherals are used, the corresponding pins and SPI host should be configured accordingly. For example, we will use SPI3 for the SD card in the future, and the pins and SPI host should be configured accordingly.