I'm using the most recent Arduino wifi shield on top of an Arduino Uno. I'm using the current wifiserver to communicate with an html page on another computer via XMLHTTPRequest - the Arduino reads servo settings (from the url) and returns some sensor readings (in JSON) - this all works mostly fine and dandy.
- My Arduino is amazingly slow. It's taking, on average 1.3seconds to reply to a wifi html request. Very little variance over 200+ tests. My code is based strongly on the example code - my code is at bottom
WIFI - start searching
Attempting to connect to SSID: TRENDnet
SSID: TRENDnet
IP Address: 192.168.1.100
signal strength (RSSI):-25 dBm
Msg:1, elapsed: 2651 ms
Msg:2, elapsed: 1323 ms
Msg:3, elapsed: 1323 ms
Msg:4, elapsed: 1324 ms
- the wifi seems flaky. After awhile it seems to just give up the ghost. Earlier I found that I was using lots of String manipulation and possibly running out of space - changed everything to fixed char buffers and the early problems went away. Is there an upgrade to the wifi firmware I should be flashing?
My code follows...
char inBuff[80]; // global
void vWifiActiveState() { // Called directly from loop() when we have an active wifi connection
// Following code based strongly on example
WiFiClient client = server.available(); // listen for incoming clients
if (client) {
int index=0;
int lineNo=0;
boolean weLike = false; // only respond to messages that pertain to us (i.e., would like to ignore favicon.ico requests if possible...
// Serial.println("new client: "); // try to reduce extru cruft to speed things up???
long start = millis();
while (client.connected()) {
if (client.available()) {
char c = client.read(); // read character
// Serial.print(c);
if ( c != '\r' ) { // ignore \r characters
inBuff[index++] = c; // save line in buffer
if ( index >= 80 ) // ignore really long lines
index=70;
if ( c == '\n' ) // make into true string
inBuff[index] = 0;
if (c == '\n' && (index <= 1)) { // http request ends with a blank line, implies time for us to respond - always send back our readings
client.println("HTTP/1.1 200 OK");
client.println("Content-Type: text/html");
client.println("Access-Control-Allow-Origin: *"); // to allow XMLHTTPRequest
client.println("Connnection: close");
client.println();
if ( weLike ) {
int anaValue1 = analogRead(pinRelativeWind1);
int anaValue2 = analogRead(pinRelativeWind2);
int iWater1 = digitalRead(pinWater1);
int iWater2 = digitalRead(pinWater2);
client.print("{\"ArdRelativeWind1\":");
client.print(anaValue1);
client.print(",\"ArdRelativeWind2\":");
client.print(anaValue2);
client.print(",\"ArdWater1\":");
client.print(iWater1);
client.print(",\"ArdWater2\":");
client.print(iWater2);
client.println("}");
} else {
Serial.println("WE DO NOT LIKE!!");
}
break;
}
if (c == '\n') {
if ( lineNo == 0 ) { // first line - this holds the GET url ...
char *get = strstr( inBuff, aGet);
char *set = strstr( inBuff, aSet);
if ( get ) { // just get values
weLike = true;
} else if ( set ) { // read value to set servos
char *rudder = strstr( inBuff, aSetRudder);
char *sail = strstr( inBuff, aSetSail);
int iRudder = atoi( rudder + 7 ); // move past the 'rudder='
int iSail = atoi( sail + 5 ); // move past the 'sail='
if ( (iRudder>=0) && (iSail>=0) ) { // dbl check for good values
vServosOut( iRudder, iSail );
}
}
} else {
// skip line - other heading information
}
lineNo++;
index=0;
}
}
}
}
// give the web browser time to receive the data
delay(1);
// close the connection:
client.stop();
// Serial.println("client disonnected");
Serial.println("Msg:"+String(++iMsgCount)+", elapsed: "+String(millis()-start)+" ms");
iBlinkAction = !iBlinkAction;
digitalWrite(pinLEDAction,iBlinkAction?HIGH:LOW); // flips every time a request is received
}
}
- though I put this line in just before submitting to get some output to show in my submission.