3

I have an LDR/Photocell which sends a value 1 or 0 (depending on the value) to a text file on my web address. The code works for a few seconds then prints out No Socket available.

Any help will be appreciated; code below.

#include <SPI.h>
#include <WiFi.h>

int LDR = A0;
int LED = 11;
char ssid[] = "SSID";
char password[] = "password";
int status = WL_IDLE_STATUS;


char server[] = "www.example.com";
int value;

void setup() {
  Serial.begin(9600);
  pinMode(LDR, INPUT);
  pinMode(LED, OUTPUT);
  connectWifi();
  printWifiStatus();
  // postData();
}

void loop() {
  value = analogRead(LDR);
  postData();

  delay(10000);
}

void connectWifi() {
  while (status != WL_CONNECTED) {
    Serial.print("Attempting to connect to ");
    Serial.println(ssid);
    status = WiFi.begin(ssid, password);
    delay(500);
  }
}

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");
}

void postData() {
  WiFiClient client;
  if (client.connect(server, 80)) {
    Serial.println("Connecting...");
    if (value > 350) {
      Serial.println("0");
      digitalWrite(LED, LOW);
      String data = "value=0";
      client.print("GET /example/client.php?");
      client.print(data);
      client.println(" HTTP/1.1");
      client.println("Host: www.example.com");
      client.println("Connection: close");
      client.println(); client.println();
      //client.stop();
    } else {
      Serial.println("1");
      digitalWrite(LED, HIGH);
      String data = "value=1";
      client.print("GET /example/client.php?");
      client.print(data);
      client.println(" HTTP/1.1");
      client.println("Host: www.example.com");
      client.println("Connection: close");
      client.println(); client.println();
      //client.stop();
    }
  } else {
    Serial.println("Connection failed");
    client.stop();
  }

}

Output:

Attempting to connect to SSID
SSID: SSID
IP Address: 255.255.255.255
signal strength (RSSI):-47 dBm
Connecting...
1
Connecting...
0
Connecting...
0
Connecting...
0
No Socket available
Connection failed
No Socket available
Connection failed
No Socket available
Connection failed
No Socket available

Actual web address omitted.

  • 1
    The text “No Socket available” isn't in any of the Serial writes shown. What program produces it, and where does it appear? Also, perhaps edit question with cut and paste of serial monitor output (as text, not as picture) – James Waldby - jwpat7 Mar 30 '17 at 18:22
  • @jwpat7 Thanks for that, updated the question. – kkmonlee Mar 30 '17 at 20:20
  • Do any of the suggestions in Arduino wifi shield - “No Socket available” help? – James Waldby - jwpat7 Mar 30 '17 at 23:15
  • I assume you actually have a server listening to port 80. Also are you sure you should be using the WifiClient and not a HttpClient object? – Code Gorilla Mar 31 '17 at 9:50
2

I guess you have commented the command: //client.stop();

If you allow it, I guess you will have your code running

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