Zoltan Hudak
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.
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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.
 |  | ||
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
- mbed OS 2 see WebSwitch_mbed-dev
- ENC28J60 Ethernet module see WebSwitch_ENC28J60
- WIZ550io or W5500 Ethernet module see WebSwitch_Wiz550io.
Diff: main.cpp
- Revision:
- 11:101be77aa5db
- Parent:
- 9:161bed13b17e
- Child:
- 12:138b2b3d041a
--- a/main.cpp Tue Oct 27 14:39:27 2020 +0000
+++ b/main.cpp Tue Oct 27 16:39:39 2020 +0000
@@ -3,70 +3,66 @@
#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
-
-Serial pc(USBTX, USBRX);
+/* */
EthernetInterface* net;
TCPSocket server;
-TCPSocket* clientSocket;
-SocketAddress clientAddress;
-char receiveBuf[1024];
+TCPSocket* client;
+char httpBuf[1500];
+char httpHeader[256];
const int OFF = 0;
const int ON = 1;
-DigitalOut sw(LED1); // A digital output to be switched on/off
+const char PASSWORD[] = "secret"; // Change as you like
+DigitalOut output(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 Analyses the received URL
* @note The string passed to this function will look like this:
- * GET /HTTP/1.....
* 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 -3 just refresh page
+ * @retval -1 invalid password
* -2 no command given but password valid
- * -1 invalid password
+ * -3 just refresh page
* 0 switch off
* 1 switch on
*/
-int8_t analyseURL(string& url)
+int8_t analyseURL(char* url)
{
- if (url.length() < 5 + PASSWORD.size() + 1)
+ if (strlen(url) < (5 + strlen(PASSWORD) + 1))
return(-1);
- if (url.substr(5, PASSWORD.size()) != PASSWORD)
+ //if (url.substr(5, PASSWORD.size()) != PASSWORD)
+ if (strncmp(url + 5, PASSWORD, strlen(PASSWORD)) != 0)
return(-1);
- uint8_t pos = 5 + PASSWORD.size();
+ uint8_t pos = 5 + strlen(PASSWORD);
- if (url.substr(pos, 1) != "/")
+ //if (url.substr(pos, 1) != "/")
+
+ if (*(url + pos) != '/')
return(-1);
- if (url.substr(pos++, 1) == " ")
+ //if (url.substr(pos++, 1) == " ")
+ if (*(url + pos++) == ' ')
return(-2);
- string cmd(url.substr(pos, 5));
-
- if (cmd == "?sw=0")
+ //string cmd(url.substr(pos, 5));
+ *(url + pos + 5) = '\0'; // terminate the cmd string
+ char* cmd = ((url + pos));
+ if (strcmp(cmd, "?sw=0") == 0)
return(0);
-
- if (cmd == "?sw=1")
+ if (strcmp(cmd, "?sw=1") == 0)
return(1);
-
return(-3);
}
@@ -76,16 +72,17 @@
* @param
* @retval
*/
-string& movedPermanently(uint8_t flag)
+char* movedPermanently(uint8_t flag)
{
- if (flag == 1)
- httpContent = "/" + PASSWORD + "/";
- else
- httpContent = "";
+ memset(httpBuf, 0, sizeof(httpBuf));
+ if (flag == 1) {
+ strcpy(httpBuf, "/");
+ strcat(httpBuf, PASSWORD);
+ strcat(httpBuf, "/");
+ }
- httpContent += "<h1>301 Moved Permanently</h1>\r\n";
-
- return(httpContent);
+ strcat(httpBuf, "<h1>301 Moved Permanently</h1>\r\n");
+ return(httpBuf);
}
/**
@@ -94,92 +91,109 @@
* @param
* @retval
*/
-string& showWebPage(int status)
+char* showWebPage(int status)
{
- char roomTempStr[5];
+ char roomTempStr[10] = { };
//roomTemp = ds1820.read();
+
sprintf(roomTempStr, "%3.1f", roomTemp);
+ memset(httpBuf, 0, sizeof(httpBuf));
/*$off*/
- httpContent =
+ strcat
+ (
+ httpBuf,
"<head>"
- "<meta charset=\"utf-8\">"
- "<meta name=\"viewport\" content=\" initial-scale=1.0; maximum-scale=1.0; minimum-scale=1.0; user-scalable=0;\"/>"
- "<title>Smart Home</title>"
- "<link href='http://fonts.googleapis.com/css?family=Droid+Sans&v1' rel='stylesheet' type='text/css'>"
- "<style>"
- ".switch {"
- "position: relative;"
- "display: inline-block;"
- "width: 60px;"
- "height: 34px;"
- "}"
- ".switch input {display:none;}"
- ".slider {"
- "position: absolute;"
- "cursor: pointer;"
- "top: 0;"
- "left: 0;"
- "right: 0;"
- "bottom: 0;"
- "border-radius: 34px;"
- "background-color: #ccc;"
- "-webkit-transition: .4s;"
- "transition: .4s;"
- "}"
- ".slider:before {"
- "position: absolute;"
- "content: \"\";"
- "height: 26px;"
- "width: 26px;"
- "left: 4px;"
- "bottom: 4px;"
- "border-radius: 50%;"
- "background-color: white;"
- "-webkit-transition: .4s;"
- "transition: .4s;"
- "}"
- "input:checked + .slider {"
- "background-color: #8ce196;"
- "}"
- "input:focus + .slider {"
- "box-shadow: 0 0 1px #8ce196;"
- "}"
- "input:checked + .slider:before {"
- "-webkit-transform: translateX(26px);"
- "-ms-transform: translateX(26px);"
- "transform: translateX(26px);"
- "}"
- "</style>"
+ "<meta charset=\"utf-8\">"
+ "<meta name=\"viewport\" content=\" initial-scale=1.0; maximum-scale=1.0; minimum-scale=1.0; user-scalable=0;\"/>"
+ "<title>Smart Home</title>"
+ "<link href='http://fonts.googleapis.com/css?family=Droid+Sans&v1' rel='stylesheet' type='text/css'>"
+ "<style>"
+ ".switch {"
+ "position: relative;"
+ "display: inline-block;"
+ "width: 60px;"
+ "height: 34px;"
+ "}"
+ ".switch input {display:none;}"
+ ".slider {"
+ "position: absolute;"
+ "cursor: pointer;"
+ "top: 0;"
+ "left: 0;"
+ "right: 0;"
+ "bottom: 0;"
+ "border-radius: 34px;"
+ "background-color: #ccc;"
+ "-webkit-transition: .4s;"
+ "transition: .4s;"
+ "}"
+ ".slider:before {"
+ "position: absolute;"
+ "content: \"\";"
+ "height: 26px;"
+ "width: 26px;"
+ "left: 4px;"
+ "bottom: 4px;"
+ "border-radius: 50%;"
+ "background-color: white;"
+ "-webkit-transition: .4s;"
+ "transition: .4s;"
+ "}"
+ "input:checked + .slider {"
+ "background-color: #8ce196;"
+ "}"
+ "input:focus + .slider {"
+ "box-shadow: 0 0 1px #8ce196;"
+ "}"
+ "input:checked + .slider:before {"
+ "-webkit-transform: translateX(26px);"
+ "-ms-transform: translateX(26px);"
+ "transform: translateX(26px);"
+ "}"
+ "</style>"
"</head>"
"<body>"
- "<h2><a href=\".\" title=\"Click to refresh the page\">Smart Home</a></h2>"
- "<pre>Temperature:\t" + string(roomTempStr) + "°C</pre>"
- "<pre>Heating:\t";
-
+ "<h2><a href=\".\" title=\"Click to refresh the page\">Smart Home</a></h2>"
+ "<pre>Temperature:\t"
+ );
+ strcat(httpBuf, roomTempStr);
+ strcat(httpBuf, "°C</pre>");
+ strcat
+ (
+ httpBuf,
+ "<pre>Heating:\t"
+ );
if(status == ON) {
- httpContent +=
- "<a href=\"./?sw=0\" class=\"switch\"> "
- "<input type=\"checkbox\" checked>";
+ strcat
+ (
+ httpBuf,
+ "<a href=\"./?sw=0\" class=\"switch\"> "
+ "<input type=\"checkbox\" checked>"
+ );
}
else {
- httpContent +=
- "<a href=\"./?sw=1\" class=\"switch\"> "
- "<input type=\"checkbox\">";
+ strcat
+ (
+ httpBuf,
+ "<a href=\"./?sw=1\" class=\"switch\"> "
+ "<input type=\"checkbox\">"
+ );
}
-
- httpContent +=
- "<div class=\"slider\"></div>"
- "</a>"
- "</pre>"
- "<hr>"
- "<pre>2017 ARMmbed</pre>"
- "</body>";
-
- return httpContent;
+ strcat
+ (
+ httpBuf,
+ "<div class=\"slider\"></div>"
+ "</a>"
+ "</pre>"
+ "<hr>"
+ "<pre>2017 ARMmbed</pre>"
+ "</body>"
+ );
/*$on*/
+ return httpBuf;
}
/**
@@ -188,24 +202,21 @@
* @param
* @retval
*/
-void sendHTTP(TCPSocket& client, string& header, string& content)
+void sendHTTP(TCPSocket* client, char* header, char* content)
{
- /*$off*/
- char content_length[5] = { };
+ char content_length[10] = { };
+ sprintf(content_length, "%u\r\n", strlen(content));
+ strcat(header, "\r\nContent-Type: text/html\r\n");
+ strcat(header, "Content-Length: ");
+ strcat(header, content_length);
+ strcat(header, "Pragma: no-cache\r\n");
+ strcat(header, "Connection: About to close\r\n\r\n");
- header +=
- "\r\nContent-Type: text/html\r\n"
- "Content-Length: ";
- sprintf(content_length, "%d", content.length());
- header +=
- string(content_length) + "\r\n"
- "Pragma: no-cache\r\n"
- "Connection: About to close\r\n\r\n";
-
- string webpage = header + content;
- client.send((char*)webpage.c_str(), webpage.length());
- pc.printf("HTTP message sent to client.\n\r");
- /*$on*/
+ char c = content[0];
+ memmove(httpBuf + strlen(header), httpBuf, strlen(content)); // make room for the header
+ strcpy(httpBuf, header); // copy the header on front of the content
+ httpBuf[strlen(header)] = c;
+ client->send((uint8_t*)httpBuf, strlen(httpBuf));
}
/**
@@ -216,112 +227,101 @@
*/
int main(void)
{
- pc.printf("Starting.. \r\n\r\n");
+ printf("\r\n Starting \r\n");
+ //ethLed.start(eth_led);
+ //net = NetworkInterface::get_default_instance();
net = new EthernetInterface();
+ //net->set_network("192.168.1.181","255.255.255.0","192.168.1.1"); // use static IP address, netmask, gateway
if (!net) {
- pc.printf("Error! No network inteface found.\n");
+ 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) {
- pc.printf("Error! net->connect() returned: %d\n", r);
+ if (r != NSAPI_ERROR_OK) {
+ 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();
-
- pc.printf("IP address: %s\r\n", ip ? ip : "None");
- pc.printf("Netmask: %s\r\n", netmask ? netmask : "None");
- pc.printf("Gateway: %s\r\n\r\n", gateway ? gateway : "None");
- pc.printf("Usage: Type %s/%s/ into your web browser and hit ENTER\r\n\r\n", ip, PASSWORD.c_str());
+ SocketAddress addr;
+ net->get_ip_address(&addr);
+ printf("IP address: %s\n", addr.get_ip_address() ? addr.get_ip_address() : "None");
+ net->get_netmask(&addr);
+ printf("Netmask: %s\n", addr.get_ip_address() ? addr.get_ip_address() : "None");
+ net->get_gateway(&addr);
+ printf("Gateway: %s\n", addr.get_ip_address() ? addr.get_ip_address() : "None");
/* Open the server on ethernet stack */
server.open(net);
/* Bind the HTTP port (TCP 80) to the server */
- server.bind(ip, PORT);
+ server.bind(PORT);
- /* Can handle 5 simultaneous connections */
- server.listen(5);
+ /* Listen for clients */
+ server.listen();
//listening for http GET request
while (true) {
- pc.printf("=========================================\r\n");
-
- nsapi_error_t error;
-
- clientSocket = server.accept(&error);
- if (error != 0) {
- pc.printf("Connection failed!\r\n");
- clientSocket->close();
- continue;
- }
-
- clientSocket->getpeername(&clientAddress);
- pc.printf("Client with IP address %s connected.\r\n\r\n", clientAddress.get_ip_address());
- clientSocket->recv(receiveBuf, 1023);
- pc.printf("Data received:\r\n%s\n\r", receiveBuf);
-
- string received(receiveBuf);
-
- if (received.substr(0, 3) != "GET") {
- httpHeader = HTTP_OK;
- httpContent = "<h1>200 OK</h1>";
- sendHTTP(*clientSocket, httpHeader, httpContent);
- clientSocket->close();
- 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);
- clientSocket->close();
- continue;
- }
+ printf("=========================================\r\n");
+ printf("Ready to serve clients.\r\n");
+ net->get_ip_address(&addr);
+ printf("Usage: Type http:\/\/%s\/%s\/ into your web browser and hit ENTER\r\n", addr.get_ip_address(), PASSWORD);
+ client = server.accept();
+ if (client) {
+ client->getpeername(&addr);
+ printf("Connection succeeded!\n\rIP: %s\n\r", addr.get_ip_address());
+ client->recv(httpBuf, 1500);
+ if (strncmp(httpBuf, "GET", 3) != 0) {
+ strcpy(httpHeader, "HTTP/1.0 200 OK");
+ strcpy(httpBuf, "<h1>200 OK</h1>");
+ sendHTTP(client, httpHeader, httpBuf);
+ }
+ else
+ if ((strncmp(httpBuf, "GET", 3) == 0) && (strncmp(httpBuf + 3, " / ", 3 == 0))) {
+ strcpy(httpHeader, "HTTP/1.0 200 OK");
+ strcpy(httpBuf, "<p>Usage: http://host_or_ip/password</p>\r\n");
+ sendHTTP(client, httpHeader, httpBuf);
+ }
+ else {
+ int cmd = analyseURL(httpBuf);
+ switch (cmd) {
+ case -3:
+ // update webpage
+ strcpy(httpHeader, "HTTP/1.0 200 OK");
+ sendHTTP(client, httpHeader, showWebPage(output));
+ break;
- int cmd = analyseURL(received);
+ case -2:
+ // redirect to the right base url
+ strcpy(httpHeader, "HTTP/1.0 301 Moved Permanently\r\nLocation: ");
+ sendHTTP(client, httpHeader, movedPermanently(1));
+ break;
- switch (cmd) {
- case -3:
- // update webpage
- httpHeader = HTTP_OK;
- sendHTTP(*clientSocket, httpHeader, showWebPage(sw));
- break;
-
- case -2:
- // redirect to the right base url
- httpHeader = MOVED_PERM;
- sendHTTP(*clientSocket, httpHeader, movedPermanently(1));
- break;
+ case -1:
+ strcpy(httpHeader, "HTTP/1.0 401 Unauthorized");
+ strcpy(httpBuf, "<h1>401 Unauthorized</h1>");
+ sendHTTP(client, httpHeader, httpBuf);
+ break;
- case -1:
- httpHeader = UNAUTHORIZED;
- httpContent = "<h1>401 Unauthorized</h1>";
- sendHTTP(*clientSocket, httpHeader, httpContent);
- break;
+ case 0:
+ output = OFF; // output off
+ strcpy(httpHeader, "HTTP/1.0 200 OK");
+ sendHTTP(client, httpHeader, showWebPage(output));
+ break;
- case 0:
- sw = OFF; // turn the switch off
- httpHeader = HTTP_OK;
- sendHTTP(*clientSocket, httpHeader, showWebPage(sw));
- break;
+ case 1:
+ output = ON; // output on
+ strcpy(httpHeader, "HTTP/1.0 200 OK");
+ sendHTTP(client, httpHeader, showWebPage(output));
+ break;
+ }
+ }
- case 1:
- sw = ON; // turn the switch on
- httpHeader = HTTP_OK;
- sendHTTP(*clientSocket, httpHeader, showWebPage(sw));
- break;
+ client->close();
}
-
- clientSocket->close();
}
}