TCPClient HTTP POST on Electron is Intermitant

Troubleshooting
1

I’ve got gode running on my Photons that sets up a TCPClient, connects to a php script on my [hosted] server and manually submits an HTTP POST request with a JSON payload in the request body.

When I tried to run this same code on the Electron version of our product, the code connects [client.connect(targetServer, port) returns true] and occasionally the sever saves the JSON to it’s file and the Electron reports the response from the server. But most of the time the server logs a request to the php script, but no data is saved and the Electron reports 0 bytes returned from the server.

I added a bunch of delay()s in the the theory that TCP over the cellular connection might have more latency, to no avail.

So far haven’t been able to find a pattern to when it does and when it won’t upload the payload.

Any suggestions?

2

Could you post your code?

3

Full code is in the Test branches of the GitHub repositories linked above.

The electron version of the pushReport(Report newReport) function in publishSVPA.cpp is below.

int pushReport(Report newReport){
  String putJSON = getJSON(newReport);

  publishDebug(String("targetServer=" + targetServer));
  delay(1000);

  /*
  // Local Network debugging
  byte targetIP[] = {192, 168, 11, 36};
  targetServer = "ProlCat";
  port = 2129;
  publishDebug(String("targetIP=" +
    String(targetIP[0]) + "."+ String(targetIP[1])
    + "."+ String(targetIP[2])+ "."+ String(targetIP[3])
    ));
  */

  publishDebug(String("port=" + String(port)));

  delay(1000);

  if (client.connect(targetServer, port))
  //if (client.connect(targetIP, port))
  {
     // "PUT /api/newdeveloper/lights/3/state HTTP/1.1"
     //String putRequest = "PUT ";
     String pushRequest = "POST ";
      pushRequest.concat(targetResource);
      pushRequest.concat("  HTTP/1.1");
      pushRequest.concat("\r\n");
      pushRequest.concat("Host: ");
      pushRequest.concat(targetServer);
      pushRequest.concat("\r\n");
      pushRequest.concat("Connection: keep-alive");
      pushRequest.concat("\r\n");
      //client.println("Content-Type:   application/json;");
      pushRequest.concat("Content-Type:   text/plain; charset=UTF-8");
      pushRequest.concat("\r\n");
      pushRequest.concat("Content-Length:  ");
      pushRequest.concat(String(putJSON.length()));

    client.println(pushRequest);
    client.println();
    client.println(putJSON);
    client.println();
    client.println();

    publishDebug(String("pushRequest=" + pushRequest));
    delay(10000);

    publishDebug(String("client.available=" + String(client.available())));

    String pushResponse = "";
    char nextResponseChar;

    while (client.available())
      {
        nextResponseChar = client.read();
        pushResponse.concat(nextResponseChar);
        delay(15);
      }

    publishDebug(String("pushResponse=" + pushResponse));

    return 0;
  }
  else
  {
    publishDebug(String("putReportResult= Did not connect."));
    return -1;
  }
}
4

Added some debugging code to my php script and it looks like the JSON payload is getting cutoff after 1023 bytes with “A” appended as the 1024th byte.

"schemaVersion":"1","firmwareVersion":"8","deviceId":"2f004a000e5135343332363","nextUpdateTime":"1487476823","readings":[{"timeStamp":"-1708712930","range":"0","internalTemp":"0.000000","internalPressure":"0.000000","internalHumidity":"0.000000","soc":"0.000000","voltage":"0.000000","rssi":"0"},{"timeStamp":"0","range":"0","internalTemp":"0.000000","internalPressure":"0.000000","internalHumidity":"0.000000","soc":"0.000000","voltage":"0.000000","rssi":"0"},{"timeStamp":"0","range":"0","internalTemp":"0.000000","internalPressure":"0.000000","internalHumidity":"0.000000","soc":"0.000000","voltage":"0.000000","rssi":"0"},{"timeStamp":"0","range":"0","internalTemp":"0.000000","internalPressure":"0.000000","internalHumidity":"0.000000","soc":"0.000000","voltage":"0.000000","rssi":"0"},{"timeStamp":"0","range":"0","internalTemp":"0.000000","internalPressure":"0.000000","internalHumidity":"0.000000","soc":"0.000000","voltage":"0.000000","rssi":"0"},{"timeStamp":"0","range":"0","internalTemp":"0.000000","internalPreA
5

It sounds like your String objects are fragmenting. Strings require more RAM and are more complicated than normal char arrays, and are more likely to fragment. Using allocated C strings (char arrays) is safer.

Side note:
Is it possible to achieve this POST request using a Webhook? This would reduce data consumption on the Electron.

6

This is a bug, and it should be fixed in system firmware 0.7.0. You can’t send 1024 bytes on an Electron. 1023 or fewer is fine. I usually send 512.

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