Zoltan Hudak / Mbed OS WebSwitch_mbed-os

HTTP Server serving a simple webpage which enables to remotely turn LED1 on/off. Compile, download, run and type 'IP_address/secret/' (don't forget the last '/') into your web browser and hit ENTER.

Fork of WebSwitch_mbed-os by Zoltan Hudak

Turn LED1, or other digital output, on/off using a web browser.

In this example we create a HTTP server that will serve a simple Web page to remotely turn LED1, or other digital output, on/off by using a web browser.

/media/uploads/hudakz/webswitch03.png/media/uploads/hudakz/webswitch_mobile01.jpg

Notice that DHCP is turned on by default. The IP address assigned to the WebSwitch server along with an instruction how to use it is printed to the connected PC's serial terminal window during program start up.
To use static IP address uncomment and adjust line #221 in main.cpp.

The project was inspired by the Tuxgraphics Web Switch. Thank you Guido!

For a Web Switch using

main.cpp

Committer:
hudakz
Date:
2018-10-30
Revision:
8:47b0cb4b5b7d
Parent:
7:02a0635aeeac
Child:
9:161bed13b17e

File content as of revision 8:47b0cb4b5b7d:

#include "mbed.h"
#include "EthernetInterface.h"
#include "TCPServer.h"
#include "TCPSocket.h"
#include <stdio.h>
#include <string>
 
using namespace     std;
 
#define IP         "192.168.1.181"
#define GATEWAY    "192.168.1.1"
#define NETMASK    "255.255.255.0"
 
 
#define PORT        80
 
EthernetInterface*  net;

TCPServer           server;
TCPSocket           clientSocket;
SocketAddress       clientAddress;
char                receiveBuf[1024] = { };
 
const int           OFF = 0;
const int           ON = 1;
 
DigitalOut          sw(LED1);
float               roomTemp = 21.8;    // A temperature sensor output
 
const string        PASSWORD     = "secret";    // change as you like
const string        HTTP_OK      = "HTTP/1.0 200 OK";
const string        MOVED_PERM   = "HTTP/1.0 301 Moved Permanently\r\nLocation: ";
const string        UNAUTHORIZED = "HTTP/1.0 401 Unauthorized";
string              httpHeader;     // HTTP header
string              httpContent;    // HTTP content
 
/**
 * @brief   Defines a custom MAC address
 * @note    Uncomment the code below to define a unique MAC address.
 *          Modify the mac array items as needed.
 * @param
 * @retval
 */
//extern "C" void mbed_mac_address(char* mac) {
//    mac[0] = 0x00;
//    mac[1] = 0x01;
//    mac[2] = 0x02;
//    mac[3] = 0x03;
//    mac[4] = 0x04;
//    mac[5] = 0x05;
//};
 
/**
 * @brief   Analyses the received URL
 * @note    The string passed to this function will look like this:
 *          GET /password HTTP/1.....
 *          GET /password/ HTTP/1.....
 *          GET /password/?sw=1 HTTP/1.....
 *          GET /password/?sw=0 HTTP/1.....
 * @param   url URL string
 * @retval -1 invalid password
 *         -2 no command given but password valid
 *         -3 just refresh page
 *          0 switch off
 *          1 switch on
 */
int8_t analyseURL(string& url) {
    if(url.substr(5, PASSWORD.size()) != PASSWORD)
        return(-1);
 
    uint8_t pos = 5 + PASSWORD.size();
 
    if(url.substr(pos, 1) == " ")
        return(-2);
 
    if(url.substr(pos++, 1) != "/")
        return(-1);
 
    string  cmd(url.substr(pos, 5));
 
    if(cmd == "?sw=0")
        return(0);
 
    if(cmd == "?sw=1")
        return(1);
 
    return(-3);
}
 
/**
 * @brief
 * @note
 * @param
 * @retval
 */
string& movedPermanently(uint8_t flag) {
    if(flag == 1)
        httpContent = "/" + PASSWORD + "/";
    else
        httpContent = "";
 
    httpContent += "<h1>301 Moved Permanently</h1>\r\n";
 
    return(httpContent);
}
 
/**
 * @brief
 * @note
 * @param
 * @retval
 */
string& showWebPage(uint8_t status) {
    char roomTempStr[5];
 
    //roomTemp = ds1820.read();
    sprintf(roomTempStr, "%3.1f", roomTemp);
 
    // CSS toggle switch
    httpContent  = "<head>";
    httpContent += "<style>";
 
    httpContent += ".switch {";
    httpContent += "position: relative;";
    httpContent += "display: inline-block;";
    httpContent += "width: 60px;";
    httpContent += "height: 34px;";
    httpContent += "}";
 
    httpContent += ".switch input {display:none;}";
 
    httpContent += ".slider {";
    httpContent += "position: absolute;";
    httpContent += "cursor: pointer;";
    httpContent += "top: 0;";
    httpContent += "left: 0;";
    httpContent += "right: 0;";
    httpContent += "bottom: 0;";
    httpContent += "border-radius: 34px;";
    httpContent += "background-color: #ccc;";
    httpContent += "-webkit-transition: .4s;";
    httpContent += "transition: .4s;";
    httpContent += "}";
 
    httpContent += ".slider:before {";
    httpContent += "position: absolute;";
    httpContent += "content: \"\";";
    httpContent += "height: 26px;";
    httpContent += "width: 26px;";
    httpContent += "left: 4px;";
    httpContent += "bottom: 4px;";
    httpContent += "border-radius: 50%;";
    httpContent += "background-color: white;";
    httpContent += "-webkit-transition: .4s;";
    httpContent += "transition: .4s;";
    httpContent += "}";
 
    httpContent += "input:checked + .slider {";
    httpContent += "background-color: #8ce196;";
    httpContent += "}";
 
    httpContent += "input:focus + .slider {";
    httpContent += "box-shadow: 0 0 1px #8ce196;";
    httpContent += "}";
 
    httpContent += "input:checked + .slider:before {";
    httpContent += "-webkit-transform: translateX(26px);";
    httpContent += "-ms-transform: translateX(26px);";
    httpContent += "transform: translateX(26px);";
    httpContent += "}";
 
    httpContent += "</style>";
    httpContent += "</head>";
 
    httpContent += "<body>";
    httpContent += "<h2><a href=\".\" title=\"Click to refresh the page\">Smart Home</a></h2>";
    httpContent += "<pre>Temperature:\t" + string(roomTempStr) + "&deg;C</pre>";
    httpContent += "<pre>Heating:\t";
 
    if(status == ON) {
        httpContent += "<a href=\"./?sw=0\" class=\"switch\"> ";
        httpContent += "<input type=\"checkbox\" checked>";
    }
    else {
        httpContent += "<a href=\"./?sw=1\" class=\"switch\"> ";
        httpContent += "<input type=\"checkbox\">";
   }
 
    httpContent += "<div class=\"slider\"></div>";
    httpContent += "</a></pre>";
    httpContent += "<hr>";
    httpContent += "<pre>2017 armMBED</pre>";
    httpContent += "</body>";
 
    return httpContent;
}
 
/**
 * @brief
 * @note
 * @param
 * @retval
 */
void sendHTTP(TCPSocket& client, string& header, string& content) {
    char    content_length[5] = { };
 
    header += "\r\nContent-Type: text/html\r\n";
    header += "Content-Length: ";
    sprintf(content_length, "%d", content.length());
    header += string(content_length) + "\r\n";
    header += "Pragma: no-cache\r\n";
    header += "Connection: About to close\r\n";
    header += "\r\n";
 
    string  webpage = header + content;
    client.send((char*)webpage.c_str(), webpage.length());
    printf("HTTP sent.\n\r");
}
 
/**
 * @brief
 * @note
 * @param
 * @retval
 */
int main(void) {
    printf("Starting\r\n");
    
    //net = NetworkInterface::get_default_instance();
    
    net = new EthernetInterface();

    if (!net) {
        printf("Error! No network inteface found.\n");
        return 0;
    }

    //net->set_network (IP, NETMASK, GATEWAY);  // include this for using static IP address
    
    nsapi_size_or_error_t r = net->connect();
    if (r != 0) {
        printf("Error! net->connect() returned: %d\n", r);
        return r;
    }

   // Show the network address
    const char *ip = net->get_ip_address();
    const char *netmask = net->get_netmask();
    const char *gateway = net->get_gateway();
    printf("IP address: %s\n", ip ? ip : "None");
    printf("Netmask: %s\n", netmask ? netmask : "None");
    printf("Gateway: %s\n", gateway ? gateway : "None");   
    printf("Usage: Type %s/%s/ into your web browser and hit ENTER\r\n", ip, PASSWORD.c_str());
 
    /* Open the server on ethernet stack */
    server.open(net);
 
    /* Bind the HTTP port (TCP 80) to the server */
    server.bind(ip, 80);
 
    /* Can handle 5 simultaneous connections */
    server.listen(5);
 
    //listening for http GET request
    while(true) {
        printf("=========================================\r\n");
        printf("Ready to serve clients.\r\n");
        server.accept(&clientSocket, &clientAddress);
        printf("Connection succeeded!\n\rIP: %s\n\r", clientAddress.get_ip_address());
        clientSocket.recv(receiveBuf, 1023);
        printf("Recieved Data: %d\n\r\n\r%.*s\n\r", strlen(receiveBuf), strlen(receiveBuf), receiveBuf);
 
        string  received(receiveBuf);
 
        if(received.substr(0, 3) != "GET") {
            httpHeader = HTTP_OK;
            httpContent = "<h1>200 OK</h1>";
            sendHTTP(clientSocket, httpHeader, httpContent);
            continue;
        }
 
        if(received.substr(0, 6) == "GET / ") {
            httpHeader = HTTP_OK;
            httpContent = "<p>Usage: Type http://ip_address/password/ into your web browser and hit ENTER</p>\r\n";
            sendHTTP(clientSocket, httpHeader, httpContent);
            continue;
        }
 
        int cmd = analyseURL(received);
 
        if(cmd == -2) {
 
            // redirect to the right base url
            httpHeader = MOVED_PERM;
            sendHTTP(clientSocket, httpHeader, movedPermanently(1));
            continue;
        }
 
        if(cmd == -1) {
            httpHeader = UNAUTHORIZED;
            httpContent = "<h1>401 Unauthorized</h1>";
            sendHTTP(clientSocket, httpHeader, httpContent);
            continue;
        }
 
        if(cmd == ON) {
            sw = ON;    // turn the switch on
        }
 
        if(cmd == OFF) {
            sw = OFF;   // turn the switch off
        }
 
        httpHeader = HTTP_OK;
        sendHTTP(clientSocket, httpHeader, showWebPage(sw));
    }
}