I have a project that needs to use 2 SPI peripherals of ESP32S3, one for SPI host and one for SPI slave. It is used to connect an SPI device that has both an SPI host and an SPI slave.
The SPI host of the ESP32S3 connects to the SPI slave of the SPI device, and the SPI slave of the ESP32S3 connects to the SPI host of the SPI device, as shown in the following figure.
- SPI.jpg (27.86 KiB) Viewed 520 times
I used the spi_slave_transmit() and spi_slave_queue_trans() functions respectively, but all data frames could not be received normally. Therefore, I tested with the following code and found that the SPI frame interval was too short and the ESP32S3 could not receive all in time if i used the spi_device_queue_trans() functions.
- queue.png (158.82 KiB) Viewed 520 times
- normal_trans.png (126.65 KiB) Viewed 520 times
Code: Select all
#include <stdio.h>
#include "driver/spi_master.h"
#include "driver/spi_slave.h"
#include "esp_heap_caps.h"
#define GPIO_MOSI_S 19
#define GPIO_SCLK_S 20
#define GPIO_CS_S 21
#define GPIO_MOSI_M 35
#define GPIO_SCLK_M 34
#define GPIO_CS_M 33
esp_err_t ret;
spi_device_handle_t Master_handle;
void SPI_RX_task(void *param)
{
spi_slave_transaction_t t[6];
uint8_t *recvbuf[6];
for (uint8_t i = 0; i < 6; i++)
{
recvbuf[i] = heap_caps_malloc(6, MALLOC_CAP_DMA);
t[i].length = 6 * 8;
t[i].tx_buffer = NULL;
t[i].rx_buffer = recvbuf[i];
}
spi_slave_transaction_t *ret_trans;
while (1)
{
for (uint8_t i = 0; i < 6; i++)
{
ret = spi_slave_queue_trans(SPI2_HOST, &t[i], portMAX_DELAY);
assert(ret == ESP_OK);
}
for (uint8_t i = 0; i < 6; i++)
{
ret = spi_slave_get_trans_result(SPI2_HOST, &ret_trans, portMAX_DELAY);
assert(ret == ESP_OK);
for (uint8_t j = 0; j < 6; j++)
{
printf("%02X ", recvbuf[i][j]);
}
printf("\n");
}
}
vTaskDelete(NULL);
}
void ESP_SPI_Slave_Init(void)
{
// Configuration for the SPI bus
spi_bus_config_t buscfg = {
.mosi_io_num = GPIO_MOSI_S,
.miso_io_num = -1,
.sclk_io_num = GPIO_SCLK_S,
.quadwp_io_num = -1,
.quadhd_io_num = -1,
};
// Configuration for the SPI slave interface
spi_slave_interface_config_t slvcfg = {
.mode = 0,
.spics_io_num = GPIO_CS_S,
.queue_size = 6,
.flags = 0,
};
// Initialize SPI slave interface
ret = spi_slave_initialize(SPI2_HOST, &buscfg, &slvcfg, SPI_DMA_CH_AUTO);
assert(ret == ESP_OK);
}
void ESP_SPI_Master_Init(void)
{
spi_bus_config_t busconfig = {
.mosi_io_num = GPIO_MOSI_M,
.miso_io_num = -1,
.sclk_io_num = GPIO_SCLK_M,
.quadhd_io_num = -1,
.quadwp_io_num = -1,
};
ret = spi_bus_initialize(SPI3_HOST, &busconfig, SPI_DMA_CH_AUTO);
ESP_ERROR_CHECK(ret);
spi_device_interface_config_t mstconfig = {
.spics_io_num = GPIO_CS_M,
.clock_speed_hz = 2000000,
.mode = 3,
.queue_size = 6,
.cs_ena_pretrans = 1,
.cs_ena_posttrans = 1,
};
ret = spi_bus_add_device(SPI3_HOST, &mstconfig, &Master_handle);
ESP_ERROR_CHECK(ret);
}
void app_main(void)
{
uint8_t *sendbuf = heap_caps_malloc(6, MALLOC_CAP_DMA);
for (uint8_t i = 0; i < 6; i++)
{
sendbuf[i] = i + 1;
}
ESP_SPI_Slave_Init();
ESP_SPI_Master_Init();
xTaskCreate(SPI_RX_task, "SPI_RX_task", 1024 * 3, NULL, 1, NULL);
spi_transaction_t t[6];
for (uint8_t i = 0; i < 6; i++)
{
t[i].length = 6 * 8;
t[i].rxlength = 0;
t[i].tx_buffer = sendbuf;
t[i].rx_buffer = NULL;
t[i].flags = 0;
}
spi_transaction_t *ret_trans;
while (1)
{
// 1. use spi_device_queue_trans(), Minimum frame interval = 21.04us
// for (uint8_t i = 0; i < 6; i++)
// {
// ret = spi_device_queue_trans(Master_handle, &t[i], portMAX_DELAY);
// }
// for (uint8_t i = 0; i < 6; i++)
// {
// ret = spi_device_get_trans_result(Master_handle, &ret_trans, portMAX_DELAY);
// }
// 2. use spi_device_transmit(), Minimum frame interval = 58.8us
for(uint8_t i = 0; i < 6; i++)
{
spi_device_transmit(Master_handle, &t[i]);
}
vTaskDelay(pdMS_TO_TICKS(3000));
}
heap_caps_free(sendbuf);
vTaskDelete(NULL);
}