introduction

In this paper , Take you to write a program , test Hi3861 Of WiFi-AP Pattern , Get more familiar with relevant API Use .

Please follow this column first Lesson one In the fourth part, prepare the experimental environment .

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One 、 Programming

First , open DevEco Device Tool , In Hongmeng project hispark_pegasus_312 Folder applications/sample/wifi-iot/app/experiment Create a new folder C01_wifi_ap.

then , In the folder C01_wifi_ap Create a new file ：wifi_ap_test.c. below , We write the program in this file .

1.1 The header file

#include <stdio.h>
#include <string.h>
#include <unistd.h>

#include "ohos_init.h"
#include "cmsis_os2.h"

#include "wifi_hotspot.h"
#include "netifapi.h"

1.2 Macro definition

#define AP_SSID "Hi3861-AP"   //Hi3861 WiFi The name of the hot spot 
#define AP_PSK  "12345678"    //Hi3861 WiFi The password of the hotspot 

1.3 Global variables

//WiFi Event callback function structure 
WifiEvent g_wifiEventHandler = {0};  
// Network interface structure pointer 
static struct netif *g_lwip_netif = NULL; 
//Hi3861 Of WiFi-AP The state of the pattern , 1:  open , 0:  close 
static volatile int g_hotspotStarted = 0; 
// Access Hi3861 Of WiFi Number of hot spots 
static volatile int g_joinedStations = 0;  

1.4 function

1.4.1 Subfunctions

These sub functions are mainly introduced by calling API To achieve , They are in the task function or WiFi Event is called in the callback function .

1、 function ：PrintStationInfo

// Print the information of the site 
static void PrintStationInfo(StationInfo* info)
{
    static char macAddress[32] = {0};
    unsigned char* mac = info->macAddress;
    
    if (!info) return;
    snprintf(macAddress, sizeof(macAddress), 
    		"%02X:%02X:%02X:%02X:%02X:%02X",
             mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
    printf("PrintStationInfo: mac=%s, reason=%d \r\n", macAddress, info->disconnectedReason);
}

Function is called in this function snprintf, The function is ： According to section 3 Format specified by parameters , Put the last 6 Parameters （MAC Address of the 6 Bytes ） Become a string , And assign this character to the first parameter .

2、 function ：ChangeHotspotIpAddr

// change Hi3861-WiFi-AP Address information for 
static int ChangeHotspotIpAddr(void)
{
    int errCode = 0;

    ip4_addr_t ipaddr;   //IP Address 
    ip4_addr_t gateway;  // gateway 
    ip4_addr_t netmask;  // Subnet mask 

    g_lwip_netif = netifapi_netif_find("ap0");

    if(g_lwip_netif) 
    {
        // stop it WiFi Hot DHCP The server 
        printf("\r\n");
        printf("Stopping DHCP server ...... \r\n");
        errCode = netifapi_dhcps_stop(g_lwip_netif);
        if(errCode != ERR_OK)
        {
            printf("Error!!! errCode = %d \r\n", errCode);
            return -1;
        }
        printf("Succeed! \r\n");

        // Set up WiFi Address information of hotspot 
        printf("Changing IP address ...... \r\n");
        IP4_ADDR(&ipaddr,  192, 168, 3, 1);    
        IP4_ADDR(&gateway, 192, 168, 3, 1);     
        IP4_ADDR(&netmask, 255, 255, 255, 0);   
        errCode = netifapi_netif_set_addr(g_lwip_netif, &ipaddr, &netmask, &gateway);
        if(errCode != ERR_OK)
        {
            printf("Error!!! errCode = %d \r\n", errCode);
            return -1;
        }
        printf("Succeed! IP: 192.168.3.1 \r\n");

        // start-up WiFi Hot DHCP The server 
        printf("Starting DHCP server ...... \r\n");
        errCode = netifapi_dhcps_start(g_lwip_netif, 0, 0); 
        if(errCode != ERR_OK)
        { 
            printf("Error!!! errCode = %d \r\n", errCode);
            return -1;
        }
        printf("Succeed! \r\n");
    }
    else
    {
        printf("Error!!! g_lwip_netif is NULL!!! \r\n");
        return -1;
    }

    return 0;
}

Function IP4_ADDR Is in header file ip4_addr.h A macro with parameters defined in , Its effect is ： Is to divide 4 The number of addresses is synthesized into one stored in the big end mode 32bit Unsigned integer .

1.4.2 WiFi Event callback function

stay AP In mode , There are three kinds of WiFi event . therefore , We need to write three callback functions accordingly , For these three WiFi Deal with the incident .

1.4.3 Task function and task entry function

The task function can be understood as the main function in this program ; Task entry function is to create task function as a task , And make it ready , Accept the scheduling of the operating system .

The basic process of task function is shown in the following figure ：

step Step3-3 It's not necessary , If not changed WiFi Address information for ,WiFi Default for hotspots IP The address is ：192.168.5.1.

The code of the task function is as follows ：

// Task function 
static void WifiHotspotTaskFun(void)
{
    int errCode = 0;
    int timeout;
    
    HotspotConfig config = {0};  //WiFi Configuration parameter structure of hotspot 

    //Step1:  Get ready WiFi Configuration parameters of hotspots 
    strcpy(config.ssid, AP_SSID);             //Hi3861 WiFi The name of the hot spot 
    strcpy(config.preSharedKey, AP_PSK);      //Hi3861 WiFi The password of the hotspot 
    config.securityType = WIFI_SEC_TYPE_PSK;  //Hi3861 WiFi Encryption type of hotspot 
    config.band = HOTSPOT_BAND_TYPE_2G;       //Hi3861 WiFi Hot band 
    config.channelNum = 7;                    //Hi3861 WiFi Hot channel 

    while(1)
    {
        //Step2:  register WiFi Callback function for event 
        printf("\r\n");
        WiFiEventHandlerRegister();

        //Step3:  Turn on Hi3861 Of WiFi hotspot 
        printf("\r\n");
        printf("starting AP ...\r\n");
        StartHotspot(&config);

        //Step4:  Time delay 
        printf("\r\n");
        printf("Please connect this hotspot with your mobile phone ...\r\n");
        printf("\r\n");
        for(timeout=120; timeout>0; timeout--)
        {
            osDelay(100);
            if(timeout == 10)
            {
                printf("\r\n");
                printf("Hotspot will be closed after %d s ...... \r\n", timeout);
            }
        }

        //Step5:  close WiFi hotspot 
        StopHotspot();

        //Step6:  Cancellation WiFi Callback function for event 
        printf("\r\n");
        printf("UnRegister WifiEvent ...... \r\n");
        errCode = UnRegisterWifiEvent(&g_wifiEventHandler);
        if(errCode != WIFI_SUCCESS)
        {
            printf("Error!!! errCode = %d \r\n", errCode);
        }
        printf("Succeed! \r\n");

        //Step7:  Time delay 
        for(timeout=30; timeout>0; timeout--)
        {
            osDelay(100);
            if(timeout < 10)
            {
                printf("Hotspot will be opened after %d s ...... \r\n", timeout);
            }
        }
    }
}

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Two 、 To write / Modify the compilation script

1、 In the folder C01_wifi_ap Create a new file ：BUILD.gn. The contents of this compilation script are as follows ：

static_library("C01_wifi_ap") {
    sources = [
        "wifi_ap_test.c",
    ]
    
    include_dirs = [
        "//utils/native/lite/include",
        "//device/hisilicon/hispark_pegasus/hi3861_adapter/kal/cmsis",
        "//foundation/communication/wifi_lite/interfaces/wifiservice",
        "//device/soc/hisilicon/hi3861v100/sdk_liteos/third_party/lwip_sack/include/lwip", 
    ]
}

2、 Modify folder applications/sample/wifi-iot/app The files under the BUILD.gn：

import("//build/lite/config/component/lite_component.gni")

lite_component("app") {
    features = [
        "startup",
        "experiment/C01_wifi_ap",
    ]
}

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3、 ... and 、 compile 、 burning

A little . Reference resources ：《 Hongmeng equipment development Hello World》 Third 、 Four parts .

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Four 、 test

1、 After burning , Reference resources 《 Hongmeng equipment development Hello World》 The fifth part , Start the test program . The test program will print out some information in the terminal window according to the process of task function , As shown in the figure below ：

2、 When you see the last prompt in the above figure , You can use the mobile phone WiFi You can see it in the settings Hi3861 Of WiFi hotspot . Connect this with your mobile phone WiFi hotspot , The terminal output is shown in the figure below ：

mac It's a cell phone MAC Address ,active stations Is the current access WiFi Number of hot devices .

When the phone starts from Hi3861 Of WiFi When the hotspot is disconnected , The terminal output is shown in the figure below ：

3、 When it is about to close WiFi Hot spot , The terminal outputs the first prompt message shown in the figure below , And then in 10s After closing DHCP service 、 close AP Pattern 、 Cancellation WiFi Event callback function .

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