esp8266 at命令开发
无论哪个平台，我感觉at命令开发是及其重要的，本文介绍下如何依赖于串口通信实现at命令开发。
**1.和前面添加功能模块一样，先创建一个at命令处理任务。
void app_main(void)
{
//modify cdb 2019-12-19
// printf("SDK version:%s\n", esp_get_idf_version());
// Initialize NVS
esp_err_t ret = nvs_flash_init();
char sys_time[64] = {0};
if (ret == ESP_ERR_NVS_NO_FREE_PAGES) {
ESP_ERROR_CHECK(nvs_flash_erase());
ret = nvs_flash_init();
}
ESP_ERROR_CHECK(ret);
//初始化wifi,并且联网
initialise_wifi();
//创建mqtt 处理任务
ret = xTaskCreate((void*)mqtt_client_thread,
MQTT_CLIENT_THREAD_NAME,
MQTT_CLIENT_THREAD_STACK_WORDS,
NULL,
MQTT_CLIENT_THREAD_PRIO,
NULL);
if (ret != pdPASS) {
DBG_C("mqtt create client thread %s failed\n", MQTT_CLIENT_THREAD_NAME);
}
//创建gpio led key处理任务
ret = xTaskCreate((void*)gpio_task,
GPIO_THREAD_NAME,
GPIO_THREAD_STACK_WORDS,
NULL,
GPIO_THREAD_PRIO,
NULL);
if (ret != pdPASS) {
DBG_C("qpio thread %s failed\n", GPIO_THREAD_NAME);
}
//创建sntp处理任务
ret = xTaskCreate((void*)sntp_example_task,
SNTP_THREAD_NAME,
SNTP_THREAD_STACK_WORDS,
NULL,
SNTP_THREAD_PRIO,
NULL);
if (ret != pdPASS) {
DBG_C("sntp thread %s failed\n", SNTP_THREAD_NAME);
}
//创建atcmd处理任务
ret = xTaskCreate((void*)atcmd_task,
ATCMD_THREAD_NAME,
ATCMD_THREAD_STACK_WORDS,
NULL,
ATCMD_THREAD_PRIO,
NULL);
if (ret != pdPASS) {
DBG_C("atcmd thread %s failed\n", SNTP_THREAD_NAME);
}
//程序将进入死循环，防止退出，并且打印运行时间log，单位s，也开启rtos任务调度
while(1)
{
memset(sys_time,0,64);
get_system(sys_time);
DBG_C("the system is runing,runtime:%s\n",sys_time);
vTaskDelay(1000 / portTICK_RATE_MS);
}
}
2.实现at命令处理任务，并且作为一个独立模块。
user_atcmd.c
// Copyright 2018-2025 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/uart.h"
/**
* This is an example which echos any data it receives on UART0 back to the sender,
* with hardware flow control turned off. It does not use UART driver event queue.
*
* - Port: UART0
* - Receive (Rx) buffer: on
* - Transmit (Tx) buffer: off
* - Flow control: off
* - Event queue: off
*/
#define BUF_SIZE (512)
typedef struct atcmd_table
{
char atcmd_name[16];
void (* atcmd_fun)(int,char*);
}atcmd_table_t;
//at test处理函数
void at_test_fun(int argc,char * argv )
{
printf("-----this is test at command---\n");
}
//at 命令处理表格，也是at命令添加处，再实现对应的处理函数。
atcmd_table_t at_table[] = {
{"AT+TEST",at_test_fun},
};
//at 命令处理，其实是读串口数据
void atcmd_task(void)
{
char recvbuf[64];
char *p;
int len = 0;
char cmd[16];
char cmd_parameter[64];
int cmd_parameter_len = 0;
int at_cmd_number = 0;
int i=0;
// Configure parameters of an UART driver,
// communication pins and install the driver
uart_config_t uart_config = {
.baud_rate = 74880,
.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_driver_install(UART_NUM_0, BUF_SIZE * 2, 0, 0, NULL);
// Configure a temporary buffer for the incoming data
uint8_t *data = (uint8_t *) malloc(BUF_SIZE);
at_cmd_number = sizeof(at_table)/sizeof(atcmd_table_t);
while (1) {
memset(recvbuf,0,64);
memset(cmd,0,16);
memset(cmd_parameter,0,64);
while(1)
{
// Read data from the UART（从串口读数据）
len = uart_read_bytes(UART_NUM_0, data, BUF_SIZE, 20 / portTICK_RATE_MS);
//拷贝并且解析数据--start
memcpy(recvbuf,data,len);
p = strchr(recvbuf,'=');
if(p != NULL)
{
printf("recvbuf:%s,cmd name len:%d\n",recvbuf,(p-recvbuf));
break;
// Write data back to the UART
//uart_write_bytes(UART_NUM_0, (const char *) data, len);
}
}
memcpy(cmd,recvbuf,(p-recvbuf));
memcpy(cmd_parameter,(p+1),(len-(p-recvbuf)-1));
printf("cmd:%s\n",cmd);
cmd_parameter_len = strlen(cmd_parameter);
printf("cmd parameter:%s,len:%d\n",cmd_parameter,cmd_parameter_len);
//拷贝并且解析数据--end
//将解析处理的at命令在at命令表中查找，如果找到，则处理相对应的处理函数
for(i = 0;i<at_cmd_number;i++)
{
printf("cmd:%s,attable:%s,attable nub:%d\n",cmd,at_table[i].atcmd_name,at_cmd_number);
if(0 == strncmp(cmd,at_table[i].atcmd_name,sizeof(cmd)))
{
printf("find the same at cmd\n");
at_table[i].atcmd_fun(cmd_parameter_len,cmd_parameter);
break;
}
}
}
}
3.user_atcmd.h
#ifndef _ESP8266_MY_ATCMD_H_
#define _ESP8266_MY_ATCMD_H_
void atcmd_task(void);
#endif
4.修改component.mk
#
# Component Makefile
#
COMPONENT_SRCDIRS := mqtt gpio sntp atcmd
COMPONENT_ADD_INCLUDEDIRS += mqtt/include
COMPONENT_ADD_INCLUDEDIRS += gpio/include
COMPONENT_ADD_INCLUDEDIRS += sntp/include
COMPONENT_ADD_INCLUDEDIRS += atcmd/include
5.编译
make clean
make
注意如果想快速编译，不要make clean，直接make app即可，只会编译修改的.c代码。
6.烧录运行加测试
至此，at命令框架已经搭建好了，下一篇博客准备介绍esp8266 nvs机制，主要用于设备关机保存一些数据使用，比如，需要保存下联网信息（ssid password）,下篇通过at命令，写入ssid 和 密码，重新开机读取后，在执行联网操作。
