ESP8266 Community Forum

- Wed May 11, 2016 2:46 pm #47311 Hi all,
I hope some of you can shed some light on what is going wrong here?

My current problem is when I power down the esp8266 and power it on again it will not connect to my access point (router). When I flash my code on to the esp it works fine. If reset the module via the reset pin(with button wired to ground). It will connect to my router just fine. If I unplug the power and connect it back up it wont connect to my router anymore. It did occur to me to try and reset the router as well but it still didnt work.

Code: Select all#include <ESP8266WiFi.h>
#include <ESP8266WebServer.h>

ESP8266WebServer server(80);
const char* ssid="------";                                //router ssid
const char* password="--------";                  //router password
char WiFiAPPSK[] = "1234567890";           //ap mode password
String webSite,javaScript,XML;
int WiFiAP;

void initWiFi()
{
  int i = 0;
  WiFi.mode(WIFI_STA);
  while(WiFi.status()!=WL_CONNECTED && i < 5)  //If cant connect to router retry 5 times
  {
     WiFi.begin(ssid,password);
     i++;
     delay(500);
     Serial.print(".");
     if(WiFi.status() == WL_CONNECTED)
     {
        Serial.print("Connected to ");
        Serial.println(ssid);
        Serial.print("Station IP address: ");
        Serial.println(WiFi.localIP());
        WiFiAP = 0;
     }
  }
  Serial.println(ssid);
  Serial.println(password);
  if (WiFi.status()!= WL_CONNECTED)          //if still cant connect after 5 retries turn on ap mode
  {
    WiFi.mode(WIFI_AP);
    uint8_t mac[WL_MAC_ADDR_LENGTH];        //Create a ap name from mac address.
    WiFi.softAPmacAddress(mac);
    String macID = String(mac[WL_MAC_ADDR_LENGTH - 2], HEX) +
               String(mac[WL_MAC_ADDR_LENGTH - 1], HEX);
    macID.toUpperCase();
    String AP_NameString = "Testap " + macID;
    char AP_NameChar[AP_NameString.length() + 1];
    memset(AP_NameChar, 0, AP_NameString.length() + 1);
    for (int i=0; i<AP_NameString.length(); i++)
    {
      AP_NameChar[i] = AP_NameString.charAt(i);
    }
    WiFi.softAP(AP_NameChar, WiFiAPPSK);
    Serial.print("AP mode enabled: ");
    Serial.println(AP_NameChar);
    Serial.println(WiFi.softAPIP());
    WiFiAP = 1;
  }
}

void setup()
{
  Serial.begin(115200);
  Serial.println();
  initWiFi();
  server.on("/",handleIndex);                     //web page
  server.on("/xml",handleXML);                //web page
  server.on("/PC",handlePC);                    //web page
  server.begin();
}

void loop()
{
  server.handleClient();
}


From the above code I left out the web page portion. The web page works fine in both sta and ap modes. When the esp cant connect to my router I can connect to the esp directly (in ap mode) without a problem. After the esp fails to connect to my router I tried using println to see if the ssid and password has changed some how. It printed the correct ssid and password. I also tried wifi.disconnect() before wifi.mode(wifi_sta) but that didnt solve my problem.

What am I doing wrong here??

My setup:
Windows xp running arduino IDE 1.6.9
USB to ttl cp2102
ESP8266 ESP01 powered from usb to ttl 3.3V

- Thu May 12, 2016 2:07 am #47338 Any chance you aren't getting an IP Address?
Does the router see the client?
Signal issues - have you moved the ESP out of range?

- Thu May 12, 2016 2:37 am #47339 UniqueIdentifier,
For the ip address, is there a way to find out through esp8266 that it is not getting ip from the router? As for the router it doesnt seem to have any issues with other devices connecting to the router. I tried power cycling the router, every device hooked up straight away except the esp8266.

As for the router seeing the client. When the esp is connected to the router, it can see the client. The problem of connecting to the router is when I power cycle the esp.

For range I am sitting about 2ft away from the router.

Just a sidenote not sure if it's related. When I flashed the esp with the espressif firmware and use AT command to connect to the router. I get a very strange ip address some thing along the lines of 0.239.239.243. Not sure how or why it got that ip. I cant ping or see it on the network eventhough the esp says connected.

- Thu May 12, 2016 7:25 am #47350 This symptom looks like you have GPIO0 permanently to GND and the upload succeed but resetting or power-recycling bring you back to upload mode again since you leave the GPIO0 to GND. It need to be switched back to HIGH for Normal Execute mode.