Running a wifi server is mutually exclusive to using it as a client. #12
Description
If you load the WifiTwitterClient library that comes with the Arduino you can demonstrate this bug. If you add code to the example sketch that ships with the library (or any other sketch) to fire up a TCP server on the wifi shield, the server will start up and return 1 when server.status() is run UNTIL the client initiates a connection to its target using client.connect(). I believe you should be able to both run a server and use the wifi shield as a client (both independently and simultaneously). Here is the modified code. Dont' forget to add your ssid and password (i've put them in a keys.h file for safety).
Observe all the instances of 'serverO'. That is the code I've added to fire up a server and the resulting status() calls in the loop so you can see what happens to it as the program progresses. A functioning wifi server will always return 1 from my experience.
#include <SPI.h>
#include <WiFi.h>
#include "keys.h"
int keyIndex = 0; // your network key Index number (needed only for WEP)
int status = WL_IDLE_STATUS; // status of the wifi connection
// initialize the library instance:
WiFiClient client;
WiFiServer serverO(23);
const unsigned long requestInterval = 30*1000; // delay between requests; 30 seconds
// if you don't want to use DNS (and reduce your sketch size)
// use the numeric IP instead of the name for the server:
//IPAddress server(199,59,149,200); // numeric IP for api.twitter.com
char server[] = "api.twitter.com"; // name address for twitter API
boolean requested; // whether you've made a request since connecting
unsigned long lastAttemptTime = 0; // last time you connected to the server, in milliseconds
String currentLine = ""; // string to hold the text from server
String tweet = ""; // string to hold the tweet
boolean readingTweet = false; // if you're currently reading the tweet
void setup() {
// reserve space for the strings:
currentLine.reserve(256);
tweet.reserve(150);
//Initialize serial and wait for port to open:
Serial.begin(9600);
while (!Serial) {
; // wait for serial port to connect. Needed for Leonardo only
}
// check for the presence of the shield:
if (WiFi.status() == WL_NO_SHIELD) {
Serial.println("WiFi shield not present");
// don't continue:
while(true);
}
// attempt to connect to Wifi network:
while ( status != WL_CONNECTED) {
Serial.print("Attempting to connect to SSID: ");
Serial.println(ssid);
// Connect to WPA/WPA2 network. Change this line if using open or WEP network:
status = WiFi.begin(ssid, pass);
// wait 10 seconds for connection:
delay(10000);
}
// you're connected now, so print out the status:
printWifiStatus();
serverO.begin();
Serial.println("Server status: " + String(serverO.status()));
connectToServer();
}
void loop()
{
Serial.println("Server status: " + String(serverO.status()));
if (client.connected()) {
if (client.available()) {
// read incoming bytes:
char inChar = client.read();
// add incoming byte to end of line:
currentLine += inChar;
// if you get a newline, clear the line:
if (inChar == '\n') {
currentLine = "";
}
// if the current line ends with <text>, it will
// be followed by the tweet:
if ( currentLine.endsWith("<text>")) {
// tweet is beginning. Clear the tweet string:
readingTweet = true;
tweet = "";
// break out of the loop so this character isn't added to the tweet:
return;
}
// if you're currently reading the bytes of a tweet,
// add them to the tweet String:
if (readingTweet) {
if (inChar != '<') {
tweet += inChar;
}
else {
// if you got a "<" character,
// you've reached the end of the tweet:
readingTweet = false;
Serial.println(tweet);
// close the connection to the server:
client.stop();
}
}
}
}
else if (millis() - lastAttemptTime > requestInterval) {
// if you're not connected, and two minutes have passed since
// your last connection, then attempt to connect again:
connectToServer();
}
}
void connectToServer() {
// attempt to connect, and wait a millisecond:
Serial.println("connecting to server...");
if (client.connect(server, 80)) {
Serial.println("making HTTP request...");
// make HTTP GET request to twitter:
client.println("GET /1/statuses/user_timeline.xml?screen_name=arduino HTTP/1.1");
client.println("Host:api.twitter.com");
client.println("Connection:close");
client.println();
}
// note the time of this connect attempt:
lastAttemptTime = millis();
}
void printWifiStatus() {
// print the SSID of the network you're attached to:
Serial.print("SSID: ");
Serial.println(WiFi.SSID());
// print your WiFi shield's IP address:
IPAddress ip = WiFi.localIP();
Serial.print("IP Address: ");
Serial.println(ip);
// print the received signal strength:
long rssi = WiFi.RSSI();
Serial.print("signal strength (RSSI):");
Serial.print(rssi);
Serial.println(" dBm");
}