Arduino Uno + ESP8266 reading server's response

Question

I'm sending a GET request from Arduino Uno using ESP8266. The request is sent, but I'm unable to print the received response.

I'm using code from https://elementztechblog.wordpress.com/2015/05/13/esp8266-based-temperature-data-logger-using-arduino/

I have changed the code for connecting to my server and I can see the GET request is received on my server's log.

I tried putting

 while (ser.available())
 {
     Serial.write(ser.read());
 }

after the Serial.println("AT+CIPCLOSE"); statement.

BUT I'm not getting anything on Serial monitor after "AT+CIPCLOSE"

EDIT: Here's my entire code:

// connect 10 to TX of Serial USB
// connect 11 to RX of serial USB
SoftwareSerial ser(10, 11); // TX, RX

// this runs once
void setup()
{

    // enable debug serial
    Serial.begin(9600);
    // enable software serial
    ser.begin(9600);

    // reset ESP8266
    ser.println("AT+RST");
}
// the loop
void loop()
{

    // TCP connection
    String cmd = "AT+CIPSTART=\"TCP\",\"";
    cmd += "192.168.0.25"; 
    cmd += "\",3000";
    ser.println(cmd);

    if(ser.find("Error"))
    {
        Serial.println("AT+CIPSTART error");
        return;
    }

    // prepare GET string
    String getStr = "GET /api/myservice";

    getStr += "\r\n\r\n";

    // send data length
    cmd = "AT+CIPSEND=";
    cmd += String(getStr.length());
    ser.println(cmd);

    if(ser.find(">")){
    ser.print(getStr);
}
else
{ 
    ser.println("AT+CIPCLOSE");
    // alert user
    Serial.println("AT+CIPCLOSE");

    // CODE I FOUND FOR READING THE REPLY FROM SERVER:
    while (ser.available())
    {
         // char c = ser.read();
         Serial.write(ser.read());
         // if (c == '\r') Serial.print('\n');
    }
}

delay(1000);
}

ESP Details:

ESP-01

AT version: 0.40.0.0

I can't help you with your exact question (have been spending many hours trying to connect a ESP8266 to my arduino Nano, with no success), But you could consider using the ESP module standalone, it's not aly a wifi module, but also a microprocessor. You can even program it using the Arduino IDE. Have a look here: arduinesp.com/wifiwebserver — ErikL
Please include your code so we can see what you tried already. — Blurry Sterk
@ErikL - Off topic: Do you still want to use the ESP8266? I am currently working with it without any problems. — Blurry Sterk
@blurry, I'm still interested. Working with the ESP8266 standalone is great, but the one thing I do mis is multiple analog inputs — ErikL
@BlurrySterk, I've added the code, please have a look at it. When I try to read the response, it prints AT+CIPSEND=<LENGTH> ERROR — Dushyant Bangal

Blurry Sterk Blurry Sterk · Accepted Answer · 2016-02-01T12:15:51

If you are only struggling to read a response then the answer is simple;

You are closing the TCP connection before you try to read:

ser.println("AT+CIPCLOSE");
// alert user
Serial.println("AT+CIPCLOSE");

// CODE I FOUND FOR READING THE REPLY FROM SERVER:
while (ser.available())
{

Move the reading while into the above block just beneath ser.print(getStr); but add a delay between the two as well.

Arduino Uno + ESP8266 reading server's response

1 Answers