一、简介
ESP8266 有两个UART。UART0有TX、RX作为 系统的打印信息输出接口 和 数据收发口，而UART1只有TX，作为 打印信息输出接口（调试用）。
二、UART0接收
2.1 相关函数
2.1.1 uart_param_config
2.1.2 uart_driver_install
2.1.3 uart_read_bytes
2.2 加入代码
/*********************************************************************
* INCLUDES
*/
#include
#include
#include
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/queue.h"
#include "driver/uart.h"
#include "esp_log.h"
#include "board_uart.h"
static void uartEventTask(void *pvParameters);
/*********************************************************************
* LOCAL VARIABLES
*/
static QueueHandle_t s_uart0Queue;
static const char *TAG = "board_uart";
/*********************************************************************
* PUBLIC FUNCTIONS
*/
/**
@brief 串口驱动初始化
@param 无
@return 无
*/
void UART_Init(void)
{
// 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); // 配置串口0参数
// Install UART driver, and get the queue.
uart_driver_install(UART_NUM_0, BUF_SIZE * 2, BUF_SIZE * 2, 100, &s_uart0Queue, 0); // 安装UART驱动程序
// Create a task to handler UART event from ISR
xTaskCreate(uartEventTask, "uartEventTask", 2048, NULL, 12, NULL);
}
/*********************************************************************
* LOCAL FUNCTIONS
*/
static void uartEventTask(void *pvParameters)
{
uart_event_t event;
uint8_t *pTempBuf = (uint8_t *)malloc(UART_MAX_NUM_RX_BYTES);
for(;;)
{
// Waiting for UART event.
if(xQueueReceive(s_uart0Queue, (void *)&event, (portTickType)portMAX_DELAY))
{
bzero(pTempBuf, UART_MAX_NUM_RX_BYTES);
switch(event.type)
{
// Event of UART receving data
// We'd better handler data event fast, there would be much more data events than
// other types of events. If we take too much time on data event, the queue might be full.
case UART_DATA:
// ESP_LOGI(TAG, "[UART DATA]: %d", event.size);
uart_read_bytes(UART_NUM_0, pTempBuf, event.size, portMAX_DELAY);
// uart_write_bytes(UART_NUM_0, (const char *)pTempBuf, 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(s_uart0Queue);
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(s_uart0Queue);
break;
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;
// Others
default:
ESP_LOGI(TAG, "uart event type: %d", event.type);
break;
}
}
}
free(pTempBuf);
pTempBuf = NULL;
vTaskDelete(NULL);
}
/****************************************************END OF FILE****************************************************/
2.3 使用流程
①串口初始化
UART_Init(); // 设置串口0
②串口中断处理
uartEventTask(void *pvParameters); // 串口事件处理函数
主要修改下面这个函数
在 case UART_DATA 中使用 uart_read_bytes 读出数据然后进行处理
三、UART0发送
3.1 相关函数
3.1.1 uart_write_bytes
3.2 使用流程
①串口初始化
UART_Init(); // 设置串口0
②串口发送数据
uart_write_bytes(uart_port_t uart_num, const char *src, size_t size); // UART0 发送数据函数
四、UART1打印日志
在 ESP8266_RTOS_SDK-3.2 中任何例程中输入make menuconfig
选择 Component config
选择
Common ESP-related
选择
UART for console output
从默认串口0改为
Customon
选择
UART peripheral to use for console output 改为 UART1 输出
• 由 Leung 写于 2019 年 4 月 30 日
• 参考：ESP8266 RTOS SDK编程指南 - UART