salve a tutti, sto utilizzando da qualche settimana il modulo Ethernet insieme all’arduino uno, ha sempre funzionato senza alcun problema. Da qualche giorno quando vado a caricare il codice sulla sceda mi esce la seguente scritta:
Low memory available, stability problems may occur.
non capisco la memori non e’ piena infatti uso circa la meta della memoria disponibile…
Sketch uses 15156 bytes (46%) of program storage space. Maximum is 32256 bytes.
Global variables use 1780 bytes (86%) of dynamic memory, leaving 268 bytes for local variables. Maximum is 2048 bytes.
Non capisco dove e’ il problema…
Questo e il codice che vado a caricare:
#include <SPI.h>
#include <Ethernet.h>
void HTML (void);
int led = 13;
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; //physical mac address
byte ip[] = { 192, 168, 1, 155 }; // ip in lan (that's what you need to use in your browser. ("192.168.1.178")
byte gateway[] = { 192, 168, 1, 1 }; // internet access via router
byte subnet[] = { 255, 255, 255, 0 }; //subnet mask
EthernetServer server(80); //server port
EthernetClient client;
String readString;
int a = 0;
int b = 0;
void PulsanteON (void);
void PulsanteOFF (void);
void Pagina2 (void);
void setup() {
Serial.begin(9600);
pinMode(led, OUTPUT);
// start the Ethernet connection and the server:
Ethernet.begin(mac, ip, gateway, subnet);
server.begin();
Serial.println(Ethernet.localIP());
}
void loop() {
// Create a client connection
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.println(readString);
client.println("HTTP/1.1 200 OK"); //send new page
client.println("Content-Type: text/html");
client.println();
client.println("<HTML>");
client.println("<HEAD>");
client.println("<TITLE>Cascina Mozzini</TITLE>");
client.println("<center>");
client.println("<H1>Cascina Mozzini</H1>");
client.println("<a href=\"/?Pagina2\"\"><button style='font-size:4vw;width: 20%;height: 10%;background-color:blue; color:bark; position:fixed; top:0%; left:0%;'>Pag.2</button></a>");
client.println("<hr />");
client.println("</HEAD>");
Pagina2();
switch(b)
{
case 0:
client.println("<BODY>");
client.println("<img src=\"https://static.vecteezy.com/system/resources/previews/000/140/802/non_2x/mountain-chalet-house-vector.jpg\") style=\"width: 40%;height: 30%; position:fixed; top:15%; left:10%;\" />");
PulsanteON();
PulsanteOFF();
switch (a)
{
case 0:
client.println("<img src=\"https://image.flaticon.com/icons/png/512/18/18310.png\") style=\"width: 20%; position:fixed; top:20%; left:60%;\" />");
break;
case 1:
client.println("<img src=\"https://pngimage.net/wp-content/uploads/2018/06/lampadina-stilizzata-png-1.png\") style=\"width: 20%; position:fixed; top:20%; left:60%;\" />");
break;
}
client.println("<a href=\"/?button1on\"\"><button style='font-size:10vw;width: 30%;height: 20%;background-color:blue; color:bark; position:fixed; bottom:5%; left:5%;'>ON</button></a>");
client.println("<a href=\"/?button1off\"\"><button style='font-size:10vw;width: 30%;height: 20%;background-color:blue; color:bark; position:fixed; bottom:5%; right:5%;'>OFF</button></a>");
delay(1);
client.println("</BODY>");
client.println("</HTML>");
readString="";
delay(1);
break;
case 1:
client.println("<a href=\"/?Pagina1\"\"><button style='font-size:4vw;width: 20%;height: 10%;background-color:blue; color:bark; position:fixed; top:0%; left:0%;'>Pag.1</button></a>");
break;
}
client.stop();
}
}
}
}
}
void PulsanteON()
{ if (readString.indexOf("?button1on") >0){
a = 1;
digitalWrite(led, HIGH);
}
}
void PulsanteOFF()
{
if (readString.indexOf("?button1off") >0){
a = 0;
digitalWrite(led, LOW);
}
}
void Pagina2 ()
{
if (readString.indexOf("?Pagina2") >0){
b = 1;
}
if(readString.indexOf("?Pagina1") >0){
b = 0;
}
}
Forse non e corretto al 100% ma dovrebbe almeno caricarmelo…
Qualcuno sa come mai ho questo problema?
In attesa di una risposta auguro a tutti una buona giornata 
