ESP can't respond after TCP connection timeout
Posted: Thu Apr 16, 2015 10:49 amHello ESP world! I am trying to get my ESP to stay connected to a website using TCP connection, and it works!.... but after a certain time the Arduino is unable to talk with the ESP - and the TCP connection is lost forever, until I re-plug the Arduino into the source. In my code, I establish connection, then reset the ESP every 10 successful connections (pin 12 connected to RST on ESP), and if there is a failure I check if ESP is responding, if not reset again. It works for some time and then eventually just crashes... 
Here is the code ---
And here is the output at the point where the ESP stops communicating ---
Thank you for any help!!
Here is the code ---
Code: Select all
#include <AltSoftSerial.h>
AltSoftSerial altSerial;
#define SSID "network name" //name of wireless access point to connect to
#define PASS "pass" //wifi password
#define DST_IP "23.229.249.101" //site ip
int loops = 1; //a counter for testing
void setup() //initialise device & connect to access point in setup
{
altSerial.begin(9600); // hardware serial connects to esp8266 module
Serial.begin(9600); // arduino serial
reset();
}
void loop()
{
altSerial.println("AT");
delay(1000);
if(altSerial.find("OK")) {
Serial.print("Reset OK");
}
// Serial.print("loops = "); //check for successful connections to server
String cmd = "AT+CIPSTART=\"TCP\",\""; //make this command: AT+CPISTART="TCP","146.227.57.195",80
cmd += DST_IP;
cmd += "\",80";
altSerial.println(cmd); //send command to device
delay(2000); //wait a little while for 'Linked' response - this makes a difference
if(!altSerial.find("ERROR"))
{
Serial.println(" CONNECT GOOD");
}
else
{
Serial.println("connection problem"); //weak spot! Need to recover elegantly
reset();
}
//cmd = "GET /~sexton/test.txt HTTP/1.0\r\n"; //construct http GET request
// cmd += "Host: cse.dmu.ac.uk\r\n\r\n";
cmd = "GET http://harvestboxbeta.com/plants/status/get HTTP/1.0\r\n";
cmd += "Host: www.harvestboxbeta.com\r\n\r\n"; //test file on my web
altSerial.print("AT+CIPSEND="); //www.cse.dmu.ac.uk/~sexton/test.txt
altSerial.println(cmd.length()); //esp8266 needs to know message length of incoming message - .length provides this
if(altSerial.find(">")) //prompt offered by esp8266
{
// Serial.println("found > prompt - issuing GET request"); //a debug message
altSerial.println(cmd); //this is our http GET request
}
else
{
altSerial.println("AT+CIPCLOSE"); //doesn't seem to work here?
Serial.println("No '>' prompt received after AT+CPISEND");
if(softwarereset())
Serial.print("--ready--");
else
reset();
}
//Parse the returned header & web page. Looking for 'Date' line in header
if (altSerial.find("Date: ")) //get the date line from the http header (for example)
{
Serial.print("Conection established = "); //check for successful connections to server
Serial.println(loops);
loops++;
for (int i=0;i<31;i++) //this should capture the 'Date: ' line from the header
{
if (altSerial.available()) //new cahracters received?
{
char c=altSerial.read(); //print to console
Serial.write(c);
}
else i--; //if not, keep going round loop until we've got all the characters
}
}
delay(500);
altSerial.println("AT+CIPCLOSE");
if(altSerial.find("Unlink")) //rarely seems to find Unlink? :(
{
Serial.println("Connection Closed Ok!");
}
else
{
Serial.println("connection close failure");
}
//reset esp
if(loops%10==0)
reset();
}
//------------------------------------------------------------------------------------
void reset()
{
digitalWrite(12,HIGH);
digitalWrite(13,HIGH);
delay(2000);
digitalWrite(12,LOW);
digitalWrite(13,LOW);
altSerial.begin(9600);
if(!cwmode3()) Serial.println("cwmode3 failed");
boolean wifi_connected=false; //not connected yet...
for(int i=0;i<5;i++) //attempt 5 times to connect to wifi - this is a good idea
{
if(connectWiFi()) //are we connected?
{
wifi_connected = true; //yes
break; //get outta here!
}
}
}
//------------------------------------------------------------------------------
boolean connectWiFi()
{
String cmd="AT+CWJAP?";
altSerial.println(cmd);
delay(2000);
if(altSerial.find(SSID)) //healthy response
{
Serial.println("Network recognized!");
return true;
}
cmd="AT+CWJAP=\""; //form eg: AT+CWJAP="dynamode","55555555555555555555555555"
cmd+=SSID;
cmd+="\",\"";
cmd+=PASS;
cmd+="\"";
altSerial.println(cmd);
delay(5000); //give it time - my access point can be very slow sometimes
if(altSerial.find("OK")) //healthy response
{
Serial.println("Connected to WiFi!");
return true;
}
else
{
Serial.println("Not connected to WiFi...");
return false;
}
}
//--------------------------------------------------------------------------------
//ditch this in favour of hardware reset. Done
boolean softwarereset()
{
altSerial.println("AT+RST");
if (altSerial.find("ready"))
{
return true;
}
else
{
return false;
}
}
boolean cwmode3()
// Odd one. CWMODE=3 means configure the device as access point & station. This function can't fail?
{
altSerial.println("AT+CWMODE=3");
if (altSerial.find("no change")) //only works if CWMODE was 3 previously
{
return true;
}
else
{
return false;
}
}
And here is the output at the point where the ESP stops communicating ---
Code: Select all
Network recognized!
Reset OK CONNECT GOOD
Conection established = 40
Thu, 16 Apr 2015 15:41:14 GMT
Connection Closed Ok!
Reset OK CONNECT GOOD
Conection established = 41
Thu, 16 Apr 2015 15:41:19 GMT
connection close failure
CONNECT GOOD
No '>' prompt received after AT+CPISEND
cwmode3 failed
Not connected to WiFi...
Not connected to WiFi...
Not connected to WiFi...
Not connected to WiFi...
Not connected to WiFi...
connection close failure
CONNECT GOOD
No '>' prompt received after AT+CPISEND
cwmode3 failed
Not connected to WiFi...
Not connected to WiFi...
...repeated
Thank you for any help!!