Hello ,
I have an arduino mega with Ethernet Shield and also with a microSD card inserted
I’ve been trying to configure the arduino as a server which has the ability of selecting automatically a IP to host the webpage , because when faced with the situation of trying to connect to a wireless router which assigns IP addresses to a lot of devices is very time consuming to find manually a free IP address .
So far i tried to approaches but i failed : 1. I start with an address , but if i don’t receive any client data within 5 seconds i proceed to incrementing the last byte of the IP address.
But this approach doesn’t do anything but incrementing all the time the IP address without finding a free one to host the webpage
#include <SPI.h>
#include <Ethernet.h>
#include <SD.h>
// initialize the library with the numbers of the interface pins
// MAC address from Ethernet shield sticker under board
byte mac = {
0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress ip(192, 168, 0, 14); // server IP address
EthernetServer server(80); // create a server at port 80 coresponds to HTTP
File webFile; // file stored on the uSD card
int i=1;
void setup() {
Ethernet.begin(mac, ip); // initialize Ethernet device
server.begin(); // start to listen for clients
Wire.begin(); // join i2c bus
Serial1.begin(9600);
Serial.begin(9600);
Serial.print("server is at ");
Serial.println(Ethernet.localIP());
//
// initialize SD card
Serial.println(“Initializing SD card…”);
if (!SD.begin(4)) { // pin 4 stands for CS ( Chip Select ) of SPI
Serial.println(“ERROR - SD card initialization failed!”);
return; // init failed
}
Serial.println(“SUCCESS - SD card initialized.”);
// check for google2 file
if (!SD.exists(“google2.htm”)) {
Serial.println(“ERROR - Can’t find google2.htm file!”);
return; // can’t find google2 file
}
Serial.println(“SUCCESS - Found google2.htm file.”);
}
void loop() {
EthernetClient client = server.available(); // try to get client
while ( !client )
{ if ( client || millis()-timer>5000)
break;
}
if (client) { // got client?
Serial.println(" Gotclient ");
…
} // end if (client)
else if ( !client) {
i++;
IPAddress ipv( 192,168,0,i);
Ethernet.begin(mac,ipv);
server.begin();
delay(5);
timer=millis();
Serial.print("server is at ");
Serial.println(Ethernet.localIP());
} // loop
- In the second approach i tried to use the DHCP to get a free address and then create the server with that address . This approach works fine for this task but i cannot use anymore my SD card - it’s not being initialized anymore ( a get an IP address and by page displays everything except the content of the SD card ).
I read that because SD and ethernet controller share one SPI bus they cannot be used at the same time , but i found out that this restriction doesn’t apply if i don’t use the DHCP and select manually the IP address
#include <Wire.h> // for IIC communication
#include <SPI.h>
#include <Ethernet.h>
#include <SD.h>
// initialize the library with the numbers of the interface pins
// MAC address from Ethernet shield sticker under board
byte mac = {
0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
EthernetServer server(80); // create a server at port 80 coresponds to HTTP
File webFile; // file stored on the uSD card
int i=1;
char ipAddr={’ ‘,’ ‘,’ ‘,’ ‘,’ '};
void setup() {
// start the Ethernet connection:
if (Ethernet.begin(mac) == 0) {
Serial.println(“Failed to configure Ethernet using DHCP”);
// no point in carrying on, so do nothing forevermore:
for(;
;
}
// print your local IP address:
Serial.print("My IP address: ");
for (byte thisByte = 0; thisByte < 4; thisByte++) {
// print the value of each byte of the IP address:
ipAddr[thisByte] = Ethernet.localIP()[thisByte];
Serial.print(Ethernet.localIP()[thisByte], DEC);
Serial.print(“.”);
}
IPAddress ip (ipAddr[0],ipAddr[1],ipAddr[2],ipAddr[3]);
Ethernet.begin(mac, ip); // initialize Ethernet device
server.begin(); // start to listen for clients
Serial1.begin(9600);
Serial.print("server is at ");
Serial.println(Ethernet.localIP());
Serial.println(“Initializing SD card…”);
if (!SD.begin(4)) { // pin 4 stands for CS ( Chip Select ) of SPI
Serial.println(“ERROR - SD card initialization failed!”);
return; // init failed
}
Serial.println(“SUCCESS - SD card initialized.”);
// check for google2 file
if (!SD.exists(“google2.htm”)) {
Serial.println(“ERROR - Can’t find google2.htm file!”);
return; // can’t find google2 file
}
Serial.println(“SUCCESS - Found google2.htm file.”);
}
//
}
// initialize SD card
void loop() {
EthernetClient client = server.available(); // try to get client
if (client) { // got client?
Serial.println(" Gotclient ");
…
} // end if (client)
} // loop
Does anyone have a clue how to solve this problem ??
Thank you