Zoltan Hudak
HTTP Server serving a simple webpage which enables to remotely turn a digital output on/off. Compile, download, run and type 'IP_address/secret/' (don't forget the last '/') into your web browser and hit ENTER.
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 the mbed board, on/off by using a web browser. An inexpensive ENC28J60 Ethernet module is used to assure connection between the mbed board and the Ethernet network (Internet). The ENC28J60 Ethernet module is driven by the UIPEthernet library.
Needed parts:
- mbed board
- ENC28J60 Ethernet module
- Wires
- Web browser (Internet Explorer, Safari, Firefox, Chrome ...) running on Windows, Mac, Linux, iPhone or Android device.
 |  |
Notice that DHCP is turned on by default. If you prefer to use static IP address then uncomment line 234
The IP address assigned to the WebSwitch server along with an instruction how to use it is printed in the connected PC's serial terminal window during program start up.
Warning
Please notice that the 3.3V power supply chip (RT8183-B) installed on an STM32F103C8T6 board is not rated to power also the ENC28J60 board.
The project was inspired by the Tuxgraphics Web Switch. Thank you Guido!
NOTE:
- For a Web Switch using a WIZ550io or W5500 Ethernet module see WebSwitch_Wiz550io.
- For a Web Switch using mbed's built in Ethernet PHY see WebSwitch_mbed-dev or WebSwitch_mbed-os .
Diff: main.cpp
- Revision:
- 11:6c0b20227ca2
- Parent:
- 10:b47c7921346f
- Child:
- 12:7c46dcf6f7e2
--- a/main.cpp Tue Aug 27 15:03:19 2019 +0000
+++ b/main.cpp Tue Aug 27 22:10:13 2019 +0000
@@ -6,7 +6,9 @@
using namespace std;
-// To be used when static IP is needed
+//#define DEBUG
+
+// To be used when a static IP is needed
#define IP "192.168.1.35"
#define GATEWAY "192.168.1.1"
#define NETMASK "255.255.255.0"
@@ -15,17 +17,18 @@
// The ENC28J60 chip doesn't have a built-in MAC address.
// It's up to us to provide one which is unique within the connected network.
// So modify the one below accordingly.
-const uint8_t MAC[6] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05 };
-UipEthernet net(MAC, D11, D12, D13, D10); // mosi, miso, sck, cs
-TcpServer server; // TCP server running on this mbed device
-TcpClient* client; // TCP client communicating with a HTTP Browser running on a PC or Mobile device
+const uint8_t MAC[6] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x06 };
+UipEthernet net(MAC, D11, D12, D13, D10); // mosi, miso, sck, cs
+TcpServer server;
+TcpClient* client;
+char receiveBuf[1024];
const int OFF = 0;
const int ON = 1;
-DigitalOut output(D3); // A digital output to be switched on/off
-float roomTemp = 21.8; // A dummy temperature sensor output
-const string PASSWORD = "secret"; // Change as you like
-string httpHeader; // HTTP header
-string httpContent; // HTTP content
+DigitalOut output(D3); // A digital output to be switched on/off
+float roomTemp = 21.8; // A temperature sensor output
+const string PASSWORD = "secret"; // Change as you like
+string httpHeader; // HTTP header
+string httpContent; // HTTP content
/**
* @brief Analyses the received URL
@@ -202,7 +205,7 @@
"Connection: About to close\r\n\r\n";
string webpage = header + content;
- client.write((uint8_t*)webpage.c_str(), webpage.length());
+ client.send((uint8_t*)webpage.c_str(), webpage.length());
/*$on*/
}
@@ -229,7 +232,7 @@
printf("Netmask: %s\r\n", netmask ? netmask : "None");
printf("Gateway: %s\r\n\r\n", gateway ? gateway : "None");
printf("------------------------------------------------------\r\n");
- printf("Usage: Type %s/%s/ into your web browser and hit ENTER\r\n\r\n", net.get_ip_address(), PASSWORD.c_str());
+ printf("Usage: Type %s/%s/ into your web browser and hit ENTER\r\n", net.get_ip_address(), PASSWORD.c_str());
printf("------------------------------------------------------\r\n");
/* Open the server on ethernet stack */
@@ -241,69 +244,67 @@
/* Can handle 5 simultaneous connections */
server.listen(5);
- while (1) {
+ while (true) {
client = server.accept();
if (client) {
- size_t size = client->available();
-
- if (size > 0) {
- uint8_t* buf = (uint8_t*)malloc(size);
- size = client->read(buf, size);
-
- string received((char*)buf);
- free(buf);
+ client->recv((uint8_t*)receiveBuf, client->available());
+#ifdef DEBUG
+ printf("Client with IP address %s connected.\r\n\r\n", client->getpeername());
+ printf("Data received:\r\n%s\n\r", receiveBuf);
+#endif
+ string received(receiveBuf);
- if (received.substr(0, 3) != "GET") {
- httpHeader = "HTTP/1.0 200 OK";
- httpContent = "<h1>200 OK</h1>";
- sendHTTP(*client, httpHeader, httpContent);
- client->close();
- continue;
- }
+ if (received.substr(0, 3) != "GET") {
+ httpHeader = "HTTP/1.0 200 OK";
+ httpContent = "<h1>200 OK</h1>";
+ sendHTTP(*client, httpHeader, httpContent);
+ client->close();
+ continue;
+ }
- if (received.substr(0, 6) == "GET / ") {
- httpHeader = "HTTP/1.0 200 OK";
- httpContent = "<p>Usage: http://host_or_ip/password</p>\r\n";
- sendHTTP(*client, httpHeader, httpContent);
- client->close();
- continue;
- }
+ if (received.substr(0, 6) == "GET / ") {
+ httpHeader = "HTTP/1.0 200 OK";
+ httpContent = "<p>Usage: http://host_or_ip/password</p>\r\n";
+ sendHTTP(*client, httpHeader, httpContent);
+ client->close();
+ continue;
+ }
- int cmd = analyseURL(received);
+ int cmd = analyseURL(received);
- switch (cmd) {
- case -3:
- // update webpage
- httpHeader = "HTTP/1.0 200 OK";
- sendHTTP(*client, httpHeader, showWebPage(output));
- break;
+ switch (cmd) {
+ case -3:
+ // update webpage
+ httpHeader = "HTTP/1.0 200 OK";
+ sendHTTP(*client, httpHeader, showWebPage(output));
+ break;
- case -2:
- // redirect to the right base url
- httpHeader = "HTTP/1.0 301 Moved Permanently\r\nLocation: ";
- sendHTTP(*client, httpHeader, movedPermanently(1));
- break;
+ case -2:
+ // redirect to the right base url
+ httpHeader = "HTTP/1.0 301 Moved Permanently\r\nLocation: ";
+ sendHTTP(*client, httpHeader, movedPermanently(1));
+ break;
- case -1:
- httpHeader = "HTTP/1.0 401 Unauthorized";
- httpContent = "<h1>401 Unauthorized</h1>";
- sendHTTP(*client, httpHeader, httpContent);
- break;
+ case -1:
+ httpHeader = "HTTP/1.0 401 Unauthorized";
+ httpContent = "<h1>401 Unauthorized</h1>";
+ sendHTTP(*client, httpHeader, httpContent);
+ break;
- case 0:
- output = OFF; // output off
- httpHeader = "HTTP/1.0 200 OK";
- sendHTTP(*client, httpHeader, showWebPage(output));
- break;
+ case 0:
+ output = OFF; // output off
+ httpHeader = "HTTP/1.0 200 OK";
+ sendHTTP(*client, httpHeader, showWebPage(output));
+ break;
- case 1:
- output = ON; // output on
- httpHeader = "HTTP/1.0 200 OK";
- sendHTTP(*client, httpHeader, showWebPage(output));
- break;
- }
+ case 1:
+ output = ON; // output on
+ httpHeader = "HTTP/1.0 200 OK";
+ sendHTTP(*client, httpHeader, showWebPage(output));
+ break;
}
+
client->close();
}
}