ESP2866 problem with long http

Using Arduino Networking, Protocols, and Devices
#1

Hi,
I’d like to use the ESP8266 to controle my Kodi Mediacenter but Kodi sends an error because the http address is broken.
Getting weatherinformations from
GET /data/2.5/weather?id="12345 HTTP/1.0\r\nHost: api.openweathermap.org\r\n\r\n
is no problem.

GET /jsonrpc?request={“jsonrpc”:“2.0”,“method”:“Player.Open”,“params”:{“item”:{“file”:“smb://CLOUDSERVER/Mediaserver/Musik/CDs/Daft Punk/Random Access Memories/13 Contact.mp3” } }, “id”: 1} HTTP/1.0\r\nHost: 192.168.0.20\r\n\r\n
dosen’t work. when i read the buffer after writing the command i get one of these outputs:

GET /jsonrpc?request={"jsonrpc":"2.0","method":"Player.Open","20


END OK

IPD,184:HTTP/1.1 200 OK
ontent-Length: 76
ontent-Type: application/json
ate: Thu, 27 Aug 2015 02:57:08 GMT
"error":{"code":-32700,"message":"Parse error."},"id":null,"jsonrpc":"2.0"}
K

K
nlink

_______________________________________________________________

GET /jsonrpc?request={"jsonrpc":"2.0","method":"Player.Open","20


RROR
nlink

_______________________________________________________________

GET /jsonrpc?request={"jsonrpc":"2.0","method":"Player.Open","20ies/13 Contact.mp3" } }, "id": 1} HTTP/1.0


RROR
nlink

Here is my code:

  String kodiIp = "192.168.0.20";
  String cmd = "AT+CIPSTART=\"TCP\",\"";
  cmd += kodiIp;
  cmd += "\",80";
  Serial3.println(cmd);
  if(Serial3.find("Error")) return;
  cmd = "GET /jsonrpc?request={\"jsonrpc\":\"2.0\",\"method\":\"Player.Open\",\"params\":{\"item\":{\"file\":\"smb://CLOUDSERVER/Mediaserver/Musik/CDs/Daft Punk/Random Access Memories/13 Contact.mp3\" } }, \"id\": 1}";
  cmd += " HTTP/1.0\r\nHost: ";
  cmd += kodiIp;
  cmd += "\r\n\r\n";
  Serial3.print("AT+CIPSEND=");
  Serial3.println(cmd.length());
  if(Serial3.find(">")){
  }else{
    Serial3.println("AT+CIPCLOSE");
    return;
  }
  Serial3.print(cmd);

Has anybody an idea where to find the problem?

edit: hm… 76 bytes semes to be the maximum. every GET message gets cut down to 76 chars. same problem if i write it over serial in smaller parts.

#2

I know next to nothing about wifi coding but I happened to be watching a video on this site and at about 1 min 58 seconds into the video the author discusses a point that may be your problem. - Scotty

#3

thanks :slight_smile: that semes to be the problem… (arduinos serial buffer is to small)
but i can’t solve the problem like in the video.

cmd = "GET /part1/part2 HTTP/1.0\r\nHost: 192.168.0.20\r\n\r\n";
Serial3.print("AT+CIPSEND=");
Serial3.println(cmd.length());

if(Serial3.find(">")){
}else{
    Serial3.println("AT+CIPCLOSE");
    return;
}


cmd = "GET /part1/";
Serial3.print(cmd);
delay(2000);

cmd = "part2 HTTP/1.0\r\nHost: 192.168.0.20\r\n\r\n";
Serial3.print(cmd);

for example resets the esp8266.
if i empty the buffer doing
for(int i = 0; i<64; i++)if(charAvailable())Serial3.read();
it does, too.

cmd = "GET /part1/";
Serial3.print("AT+CIPSEND=");
Serial3.println(cmd.length());

if(Serial3.find(">")){
}else{
    Serial3.println("AT+CIPCLOSE");
    return;
}
Serial3.print(cmd);

cmd = "part2 HTTP/1.0\r\nHost: 192.168.0.20\r\n\r\n";
Serial3.print("AT+CIPSEND=");
Serial3.println(cmd.length());

if(Serial3.find(">")){
}else{
    Serial3.println("AT+CIPCLOSE");
    return;
}
Serial3.print(cmd);

dosen’t work as well

#4

See what happens if u add this line to your code.

#define SERIAL_RX_BUFFER_SIZE 256
#define SERIAL_TX_BUFFER_SIZE 256

It should work if placed before or after calling any libraries, but be sure to test both options.

Alternatively you can edit the line in HardwareSerial.h

Edit: Just realized u are transmitting, but same applies, just change RX to TX.

#5

ah, thanks! changing the define in hardwareserial.h helped to increase the buffer. now the whole command can be send at once :slight_smile:

when there are seperate buffers for tx and rx, why do i read the command written to tx from the rx buffer?

#6

Initially I advised to only change only the RX buffer because when the ESP8266 communicates it sends a "large" message, so u need a bigger buffer to receive messages from the ESP8266.

But then I realized you were having trouble transmitting a large message, hence I added the change to the TX buffer as well.

#7

understood that.
my question is why i read stuff from my rx buffer with serial.read() when i've write it to the tx buffer with serial.print()? thaught they are seperate

#8