1、串口回环测试（电脑串口发送数据，原数据返回）
代码如下
/*串口初始化
* */
void Uart0_Init()
{
/* Configure parameters of an UART driver,
* communication pins and install the driver */
uart_config_t uart_config = {
.baud_rate = 115200,
.data_bits = UART_DATA_8_BITS,
.parity = UART_PARITY_DISABLE,
.stop_bits = UART_STOP_BITS_1,
.flow_ctrl = UART_HW_FLOWCTRL_DISABLE
};
uart_param_config(UART_NUM_0, &uart_config);
uart_set_pin(UART_NUM_0, ECHO_TEST_TXD, ECHO_TEST_RXD, ECHO_TEST_RTS, ECHO_TEST_CTS);
uart_driver_install(UART_NUM_0, BUF_SIZE * 2, 0, 0, NULL, 0);
}
static void echo_task()
{
uint8_t *data = (uint8_t *) malloc(BUF_SIZE);
while (1) {
// Read data from the UART
int len = uart_read_bytes(UART_NUM_0, data, BUF_SIZE, 20 / portTICK_RATE_MS);
// Write data back to the UART
uart_write_bytes(UART_NUM_0, (const char *) data, len);
}
}
例程2解析：串口事件处理
1、初始化串口
void Uart0even_Init()
{
uart_config_t uart_config = {
.baud_rate = 115200,
.data_bits = UART_DATA_8_BITS,
.parity = UART_PARITY_DISABLE,
.stop_bits = UART_STOP_BITS_1,
.flow_ctrl = UART_HW_FLOWCTRL_DISABLE
}; 初始化串口参数配置
uart_param_config(UART_NUM_0, &uart_config);
uart_set_pin(UART_NUM_0, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE);设置串口的发送接受引脚，本例程采用默认配置。
uart_driver_install(UART_NUM_0, BUF_SIZE * 2, BUF_SIZE * 2, 20, &uart0_queue, 0);
安装串口驱动，设置发送接受缓冲区大小，
//Set uart pattern detect function.
uart_enable_pattern_det_intr(UART_NUM_0, '+', PATTERN_CHR_NUM, 10000, 10, 10);
设置串口特殊字符串作为事件处理功能
uart_pattern_queue_reset(UART_NUM_0, 20);
分配给定长度的队列内存来保存设置模式的接受到的数据
}
static void echo_task(void *pvParameters)
{
uart_event_t event; 定义串口事件
size_t buffered_size;
uint8_t* dtmp = (uint8_t*) malloc(RD_BUF_SIZE); 开辟接受数据内存
esp_log_level_set(TAG, ESP_LOG_INFO);
设置输出日志等级
Uart0even_Init();
while (1) {
判断串口接受信息队列是否有数据，并保存到事件结构体
if(xQueueReceive(uart0_queue, (void * )&event, (portTickType)portMAX_DELAY)) {
bzero(dtmp, RD_BUF_SIZE); 数据缓冲区置0
ESP_LOGI(TAG, "uart[%d] event:", UART_NUM_0);
switch(event.type) { 判断串口事件
case UART_DATA: 串口数据事件
ESP_LOGI(TAG, "[UART DATA]: %d", event.size);
uart_read_bytes(UART_NUM_0, dtmp, event.size, portMAX_DELAY);
ESP_LOGI(TAG, "[DATA EVT]:");
uart_write_bytes(UART_NUM_0, (const char*) dtmp, event.size);
break;
//Event of HW FIFO overflow detected
case UART_FIFO_OVF:
ESP_LOGI(TAG, "hw fifo overflow");
// If fifo overflow happened, you should consider adding flow control for your application.
// The ISR has already reset the rx FIFO,
// As an example, we directly flush the rx buffer here in order to read more data.
uart_flush_input(UART_NUM_0);
xQueueReset(uart0_queue);
break;
//Event of UART ring buffer full
case UART_BUFFER_FULL:
ESP_LOGI(TAG, "ring buffer full");
// If buffer full happened, you should consider encreasing your buffer size
// As an example, we directly flush the rx buffer here in order to read more data.
uart_flush_input(UART_NUM_0);
xQueueReset(uart0_queue);
break;
//Event of UART RX break detected
case UART_BREAK:
ESP_LOGI(TAG, "uart rx break");
break;
//Event of UART parity check error
case UART_PARITY_ERR:
ESP_LOGI(TAG, "uart parity error");
break;
//Event of UART frame error
case UART_FRAME_ERR:
ESP_LOGI(TAG, "uart frame error");
break;
//UART_PATTERN_DET
case UART_PATTERN_DET: 串口设置模式事件
uart_get_buffered_data_len(UART_NUM_0, &buffered_size);获取数据缓冲区数据长度
int pos = uart_pattern_pop_pos(UART_NUM_0); 设置模式位置
ESP_LOGI(TAG, "[UART PATTERN DETECTED] pos: %d, buffered size: %d", pos, buffered_size);
if (pos == -1) {
// There used to be a UART_PATTERN_DET event, but the pattern position queue is full so that it can not
// record the position. We should set a larger queue size.
// As an example, we directly flush the rx buffer here.
uart_flush_input(UART_NUM_0);
} else {
uart_read_bytes(UART_NUM_0, dtmp, pos, 100 / portTICK_PERIOD_MS);
uint8_t pat[PATTERN_CHR_NUM + 1];
memset(pat, 0, sizeof(pat));
uart_read_bytes(UART_NUM_0, pat, PATTERN_CHR_NUM, 100 / portTICK_PERIOD_MS);
ESP_LOGI(TAG, "read data: %s", dtmp);
ESP_LOGI(TAG, "read pat : %s", pat);
}
break;
//Others
default:
ESP_LOGI(TAG, "uart event type: %d", event.type);
break;
}
}
}
free(dtmp);
dtmp = NULL;
vTaskDelete(NULL);
}