Web Relay Test Arduino Sketch

I wrote this Arduino sketch to test firing the relays on 2 of my Seeed Studio Relay Shields. Shield 1 is connected to digital pins 2 to 5 and Shield #2 is connected to digital pins 6 to 9.

This sketch enables all those pins for output and then turns them on and off for half a second (500 milliseconds) in sequence.

#include <SPI.h>
#include <Ethernet.h>


byte mac[] = { 0x90, 0xA2, 0xDA, 0x00, 0x50, 0xA0 };    //physical mac address
byte ip[] = { 192, 168, 1, 177 };   // ip in lan
byte gateway[] = { 192, 168, 1, 1 };   // internet access via router
byte subnet[] = { 255, 255, 255, 0 };                   //subnet mask
Server server(80);                                      //server port
byte sampledata=50;            //some sample data - outputs 2 (ascii = 50 DEC)            

String readString = String(30); //string for fetching data from address

void setup(){
//start Ethernet
Ethernet.begin(mac, ip, gateway, subnet);

//Set pins 2 through 9 to output
for (int i = 2; i <= 9; i++){
  pinMode(i, OUTPUT);  
}

//enable serial data print  
  Serial.begin(9600);
}
void loop(){
// Create a client connection
Client client = server.available();
  if (client) {
    while (client.connected()) {
      if (client.available()) {
        char c = client.read();
        //read char by char HTTP request
        if (readString.length() < 30) {
          //store characters to string
          readString.concat(c);
        }  
        //output chars to serial port
        Serial.print(c);
        //if HTTP request has ended
        if (c == '\n') {
          if(readString.indexOf("test=all") > -1) {

httpReply(client);

// cycle through pins 2 to 9
for (int i = 2; i <= 9; i++){
               Serial.print("Writing pin ");
               Serial.print(i);
               Serial.println(" HIGH");
               digitalWrite(i, HIGH);    // set the LED on
               delay(500);
               Serial.print("Writing pin ");
               Serial.print(i);
               Serial.println(" LOW");
               digitalWrite(i, LOW);
               delay(500);
             }
          }
          //clearing string for next read
          readString="";
          //stopping client
          client.stop();
        }
      }
    }
  }
}

void httpReply(Client client){
  client.println("HTTP/1.1 200 OK");
  client.println("Content-Type: text/html");
  client.println();
  client.println("{\"status\" : \"executing\" , \"cmd\" : \"test=all\"}");
  client.stop();
}

This code is loosely derived from code by Mareika Giacobbi of nerdydog.it for his Domotic Home project.