一、开发板编译、功能介绍
根据官方文档编译烧录成功后，我们修改下官方例子，进行开发来实现websocket。
整体流程：开发板先自动寻找指定的wifi并且连接，连接成功后，通过websocket来与服务端连接，连接成功后，服务端就可以控制开发板开关灯。
二、代码编写以及功能实现
进入目录 device/xradio/xr806/ohosdemo/
修改BUILD.gn文件新增demo:app_demo
group(“ohosdemo”) {
deps = [
#“hello_demo:app_hello”,
#“iot_peripheral:app_peripheral”,
#“wlan_demo:app_WlanTest”,
#“LED:app_led”,
“demo:app_demo”,
]
}
创建demo目录 tree -L 1
├── BUILD.gn
└── main.c
BUILD.gn内容：
import("//device/xradio/xr806/liteos_m/config.gni")
static_library("app_demo") {
configs = []
sources = [
"main.c",
]
cflags = board_cflags
include_dirs = board_include_dirs
include_dirs += [
"//kernel/liteos_m/kernel/arch/include",
"//kernel/liteos_m/kernel/arch/include",
"//base/iot_hardware/peripheral/interfaces/kits",
"//utils/native/lite/include",
"//foundation/communication/wifi_lite/interfaces/wifiservice",
"//device/xradio/xr806/xr_skylark/project",
]
}
main.c
#include <stdio.h>
#include <string.h>
#include "ohos_init.h"
#include "kernel/os/os.h"
#include "iot_gpio.h"
#include "wifi_device.h"
#include "wifi_hotspot.h"
#include "net/libwebsockets/libwebsockets.h"
#define WIFI_DEVICE_CONNECT_AP_SSID "um" //wifi名称
#define WIFI_DEVICE_CONNECT_AP_PSK "12345678" //wifi密码
#define WEBSOCKET_HOST "192.168.10.21" //服务器IP
#define WEBSOCKET_PORT 9999 //服务器端口
#define WEBSOCKET_PATH "/ws" //websocket路径
#define LIGHT_OPEN "/light/open" //开灯指令
#define LIGHT_CLOSE "/light/close" //关灯指令
static OS_Thread_t g_main_thread;
#define GPIO_ID_PA21 21
#define MAX_PAYLOAD_SIZE 10 * 1024
/**
* 会话上下文对象，结构根据需要自定义
*/
struct session_data {
int msg_count;
unsigned char buf[LWS_PRE + MAX_PAYLOAD_SIZE];
int len;
};
/**
* 某个协议下的连接发生事件时，执行的回调函数
*
* wsi：指向WebSocket实例的指针
* reason：导致回调的事件
* user 库为每个WebSocket会话分配的内存空间
* in 某些事件使用此参数，作为传入数据的指针
* len 某些事件使用此参数，说明传入数据的长度
*/
int callback( struct lws *wsi, enum lws_callback_reasons reason, void *user, void *in, size_t len ) {
struct session_data *data = (struct session_data *) user;
switch ( reason ) {
case LWS_CALLBACK_CLIENT_ESTABLISHED: // 连接到服务器后的回调
lwsl_notice( "Connected to server ok!\n" );
break;
case LWS_CALLBACK_CLIENT_RECEIVE: // 接收到服务器数据后的回调，数据为in，其长度为len
lwsl_notice( "Rx: %s\n", (char *) in );
if (strncmp(in, LIGHT_CLOSE, len))
{
//开灯操作
IoTGpioSetOutputVal(GPIO_ID_PA21, 1);
}
else if (strncmp(in, LIGHT_OPEN, len))
{
//关灯操作
IoTGpioSetOutputVal(GPIO_ID_PA21, 0);
}
break;
case LWS_CALLBACK_CLIENT_WRITEABLE: // 当此客户端可以发送数据时的回调
if ( data->msg_count < 3 ) {
// 前面LWS_PRE个字节必须留给LWS
memset( data->buf, 0, sizeof( data->buf ));
char *msg = (char *) &data->buf[ LWS_PRE ];
data->len = sprintf( msg, "你好 %d", ++data->msg_count );
lwsl_notice( "Tx: %s\n", msg );
// 通过WebSocket发送文本消息
lws_write( wsi, &data->buf[ LWS_PRE ], data->len, LWS_WRITE_TEXT );
}
break;
}
return 0;
}
/**
* 支持的WebSocket子协议数组
* 子协议即JavaScript客户端WebSocket(url, protocols)第2参数数组的元素
* 你需要为每种协议提供回调函数
*/
struct lws_protocols protocols[] = {
{
//协议名称，协议回调，接收缓冲区大小
"ws", callback, sizeof( struct session_data ), MAX_PAYLOAD_SIZE,
},
{
NULL, NULL, 0 // 最后一个元素固定为此格式
}
};
//连接wifi，并且打印ip
static int wifiConnect()
{
const char ssid_want_connect[] = WIFI_DEVICE_CONNECT_AP_SSID;
const char psk[] = WIFI_DEVICE_CONNECT_AP_PSK;
if (WIFI_SUCCESS != EnableWifi()) {
printf("Error: EnableWifi fail.\n");
return -1;
}
OS_Sleep(1);
if (WIFI_STA_ACTIVE == IsWifiActive())
printf("Wifi is active.\n");
OS_Sleep(1);
if (WIFI_SUCCESS != Scan()) {
printf("Error: Scan fail.\n");
return -1;
}
OS_Sleep(3);
WifiScanInfo scan_results[30];
unsigned int scan_num = 30;
if (WIFI_SUCCESS != GetScanInfoList(scan_results, &scan_num)) {
printf("Error: GetScanInfoList fail.\n");
return -1;
}
WifiDeviceConfig config = { 0 };
int netId = 0;
int i;
for (i = 0; i < scan_num; i++) {
if (0 == strcmp(scan_results[i].ssid, ssid_want_connect)) {
memcpy(config.ssid, scan_results[i].ssid,
WIFI_MAX_SSID_LEN);
memcpy(config.bssid, scan_results[i].bssid,
WIFI_MAC_LEN);
strcpy(config.preSharedKey, psk);
config.securityType = scan_results[i].securityType;
config.wapiPskType = WIFI_PSK_TYPE_ASCII;
config.freq = scan_results[i].frequency;
break;
}
}
if (i >= scan_num) {
printf("Error: No found ssid in scan_results\n");
return -1;
}
if (WIFI_SUCCESS != AddDeviceConfig(&config, &netId)) {
printf("Error: AddDeviceConfig Fail\n");
return -1;
}
if (WIFI_SUCCESS != ConnectTo(netId)) {
printf("Error: ConnectTo Fail\n");
return -1;
}
printf("ConnectTo Success\n");
OS_Sleep(15);
return 0;
}
void wifiDisconnect()
{
printf("\n=========== DisConnect Test Start ===========\n");
if (WIFI_SUCCESS != Disconnect()) {
printf("Error: Disconnect Fail\n");
return;
}
printf("Disconnect Success\n");
if (WIFI_SUCCESS != DisableWifi()) {
printf("Error: DisableWifi fail.\n");
return;
}
printf("DisableWifi Success\n");
printf("\n=========== DisConnect Test End ===========\n");
}
static void MainThread(void *arg)
{
int s32Ret = 0;
s32Ret = wifiConnect();
if (0 != s32Ret)
{
printf("wifiConnect failed\n");
return;
}
IoTGpioInit(GPIO_ID_PA21);
IoTGpioSetDir(GPIO_ID_PA21, IOT_GPIO_DIR_OUT);
// 用于创建vhost或者context的参数
struct lws_context_creation_info ctx_info = { 0 };
ctx_info.port = CONTEXT_PORT_NO_LISTEN;
// ctx_info.iface = NULL;
ctx_info.protocols = protocols;
ctx_info.gid = -1;
ctx_info.uid = -1;
// 创建一个WebSocket处理器
struct lws_context *context = lws_create_context( &ctx_info );
char address[] = WEBSOCKET_HOST;
int port = WEBSOCKET_PORT;
char addr_port[256] = { 0 };
sprintf(addr_port, "%s:%u", address, port & 65535 );
// 客户端连接参数
struct lws_client_connect_info conn_info = { 0 };
conn_info.context = context;
conn_info.address = address;
conn_info.port = port;
conn_info.path = WEBSOCKET_PATH;
conn_info.host = addr_port;
conn_info.origin = addr_port;
conn_info.protocol = protocols[ 0 ].name;
// 下面的调用触发LWS_CALLBACK_PROTOCOL_INIT事件
// 创建一个客户端连接
struct lws *wsi = lws_client_connect_via_info( &conn_info );
while (1) {
// 执行一次事件循环（Poll），最长等待1000毫秒
lws_service( context, 1000 );
/**
* 下面的调用的意义是：当连接可以接受新数据时，触发一次WRITEABLE事件回调
* 当连接正在后台发送数据时，它不能接受新的数据写入请求，所有WRITEABLE事件回调不会执行
*/
lws_callback_on_writable( wsi );
}
// 销毁上下文对象
lws_context_destroy( context );
wifiDisconnect();
}
//连接websocket 进行开灯，关灯操作
//wifi 连接
void demoMain(void) //(2)
{
printf("websocket Test Start\n");
if (OS_ThreadCreate(&g_main_thread, "MainThread", MainThread, NULL,
OS_THREAD_PRIO_APP, 4 * 1024) != OS_OK)
{
printf("[ERR] Create MainThread Failed\n");
}
}
SYS_RUN(demoMain);
三、效果演示
服务器用了网上下载的个WebssocketMan工具来模拟，网盘链接
链接：https://pan.baidu.com/s/1t82q_1evB5Zla-Hc1m4SYA
提取码：4pxu
登陆成功后打印显示：
登录后平台收到“/light/open”消息为点灯，“/light/close”为关灯
演示截图：
四、问题记录
在打开wifi例子，编译过程中遇到了分区叠加的错误，具体如图（感谢群里的朋友、社区以及论坛的帮助）
因为内存分配不够，官方文档描述
device\xradio\xr806\xr_skylark\project\image_cfg\readme.md
按照网上说的修改：
device\xradio\xr806\xr_skylark\project\demo\wlan_ble_demo\image\xr806\image_wlan_ble.cfg 分配不能够生效
最终解决：xr806\device\xradio\xr806\xr_skylark\project\demo\audio_demo\image\xr806\目录中将 image_auto_cal.cfg替换image.cfg
