I have a project where I need to have two Arduinos, in two different locations, equipped with sensors reading various things, which in turn should be able to rely the data to its counterpart. So it's not just one Arduino talking to the other, the communication needs to go both ways.
Combined client/server code that with some tinkering could probably do bidirectional communication with data and such.
//zoomkat 7-03-12, combined client and server
//simple button GET with iframe code
//for use with IDE 1.0
//open serial monitor and send an g to test client and
//see what the arduino client/server receives
//web page buttons make pins high/low
//use the ' in html instead of " to prevent having to escape the "
//address will look like http://192.168.1.102:84 when submited
//for use with W5100 based ethernet shields
//note that the below bug fix may be required
// http://code.google.com/p/arduino/issues/detail?id=605
#include <SPI.h>
#include <Ethernet.h>
byte mac[] = {0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; //assign arduino mac address
byte ip[] = {192, 168, 1, 102 }; // ip in lan assigned to arduino
byte gateway[] = {192, 168, 1, 1 }; // internet access via router
byte subnet[] = {255, 255, 255, 0 }; //subnet mask
EthernetServer server(84); //server port arduino server will use
EthernetClient client;
char serverName[] = "web.comporium.net"; // (DNS) zoomkat's test web page server
//byte serverName[] = { 208, 104, 2, 86 }; // (IP) zoomkat web page server IP address
String readString; //used by server to capture GET request
//////////////////////
void setup(){
pinMode(5, OUTPUT); //pin selected to control
pinMode(6, OUTPUT); //pin selected to control
pinMode(7, OUTPUT); //pin selected to control
pinMode(8, OUTPUT); //pin selected to control
//pinMode(5, OUTPUT); //pin 5 selected to control
Ethernet.begin(mac,ip,gateway,gateway,subnet);
server.begin();
Serial.begin(9600);
Serial.println("server/client 1.0 test 7/03/12"); // keep track of what is loaded
Serial.println("Send an g in serial monitor to test client"); // what to do to test client
}
void loop(){
// check for serial input
if (Serial.available() > 0)
{
byte inChar;
inChar = Serial.read();
if(inChar == 'g')
{
sendGET(); // call client sendGET function
}
}
EthernetClient client = server.available();
if (client) {
while (client.connected()) {
if (client.available()) {
char c = client.read();
//read char by char HTTP request
if (readString.length() < 100) {
//store characters to string
readString += c;
//Serial.print(c);
}
//if HTTP request has ended
if (c == '\n') {
///////////////
Serial.print(readString); //print to serial monitor for debuging
//now output HTML data header
if(readString.indexOf('?') >=0) { //don't send new page
client.println(F("HTTP/1.1 204 Zoomkat"));
client.println();
client.println();
}
else {
client.println(F("HTTP/1.1 200 OK")); //send new page on browser request
client.println(F("Content-Type: text/html"));
client.println();
client.println(F("<HTML>"));
client.println(F("<HEAD>"));
client.println(F("<TITLE>Arduino GET test page</TITLE>"));
client.println(F("</HEAD>"));
client.println(F("<BODY>"));
client.println(F("<H1>Zoomkat's simple Arduino 1.0 button</H1>"));
// DIY buttons
client.println(F("Pin5"));
client.println(F("<a href=/?on2 target=inlineframe>ON</a>"));
client.println(F("<a href=/?off3 target=inlineframe>OFF</a>
"));
client.println(F("Pin6"));
client.println(F("<a href=/?on4 target=inlineframe>ON</a>"));
client.println(F("<a href=/?off5 target=inlineframe>OFF</a>
"));
client.println(F("Pin7"));
client.println(F("<a href=/?on6 target=inlineframe>ON</a>"));
client.println(F("<a href=/?off7 target=inlineframe>OFF</a>
"));
client.println(F("Pin8"));
client.println(F("<a href=/?on8 target=inlineframe>ON</a>"));
client.println(F("<a href=/?off9 target=inlineframe>OFF</a>
"));
client.println(F("Pins"));
client.println(F(" <a href=/?off2468 target=inlineframe>ALL ON</a>"));
client.println(F(" <a href=/?off3579 target=inlineframe>ALL OFF</a>"));
client.println(F("<IFRAME name=inlineframe style='display:none'>"));
client.println(F("</IFRAME>"));
client.println(F("</BODY>"));
client.println(F("</HTML>"));
}
delay(1);
//stopping client
client.stop();
///////////////////// control arduino pin
if(readString.indexOf('2') >0)//checks for 2
{
digitalWrite(5, HIGH); // set pin 5 high
Serial.println("Led 5 On");
Serial.println();
}
if(readString.indexOf('3') >0)//checks for 3
{
digitalWrite(5, LOW); // set pin 5 low
Serial.println("Led 5 Off");
Serial.println();
}
if(readString.indexOf('4') >0)//checks for 4
{
digitalWrite(6, HIGH); // set pin 6 high
Serial.println("Led 6 On");
Serial.println();
}
if(readString.indexOf('5') >0)//checks for 5
{
digitalWrite(6, LOW); // set pin 6 low
Serial.println("Led 6 Off");
Serial.println();
}
if(readString.indexOf('6') >0)//checks for 6
{
digitalWrite(7, HIGH); // set pin 7 high
Serial.println("Led 7 On");
Serial.println();
}
if(readString.indexOf('7') >0)//checks for 7
{
digitalWrite(7, LOW); // set pin 7 low
Serial.println("Led 7 Off");
Serial.println();
}
if(readString.indexOf('8') >0)//checks for 8
{
digitalWrite(8, HIGH); // set pin 8 high
Serial.println("Led 8 On");
Serial.println();
}
if(readString.indexOf('9') >0)//checks for 9
{
digitalWrite(8, LOW); // set pin 8 low
Serial.println("Led 8 Off");
Serial.println();
}
//clearing string for next read
readString="";
}
}
}
}
}
//////////////////////////
void sendGET() //client function to send and receive GET data from external server.
{
if (client.connect(serverName, 80)) {
Serial.println("connected");
client.println("GET /~shb/arduino.txt HTTP/1.0");
client.println();
}
else {
Serial.println("connection failed");
Serial.println();
}
while(client.connected() && !client.available()) delay(1); //waits for data
while (client.connected() || client.available()) { //connected or data available
char c = client.read();
Serial.print(c);
}
Serial.println();
Serial.println("disconnecting.");
Serial.println("==================");
Serial.println();
client.stop();
}