[SOLVED] Error 400 "Bad request"

IoT Devices
1

Hi there.
This code has been working fine on my Adafruit Fona and then all of a sudden I get Error 400. I must be missing something here, Ive read and reread the API documents and I just cant see my problem.

Code below:

String varString = "{“Volume_1”: " + String(vol1,2)+ ", “Volume_2”: " + String(vol2,2)+ ", “Average”: " + String(ave,2)+ “, “Error”: " + Error + “, “Signal”: " + String(csq)+ “}” ; //build string for upload
int num = varString.length();
SerialMon.println(“Sending String:”);
SerialMon.println(varString);
SerialMon.print(“With Length :”);
SerialMon.println(num);
SerialMon.print(F(“Connecting to “));
SerialMon.print(server);
SerialMon.println(“Please wait”);
if (client.connect(server,port)) {
client.print(F(“POST /api/v1.6/devices/”));
client.print(deviceLabel);
client.print(F(” HTTP/1.1\r\n”));
client.print(F(“Host: “));
client.print(server);
client.print(F(”\r\n”));
client.print(F(“X-Auth-Token: “));
client.print(token);
client.print(F(”\r\n”));
client.print(F(“Connection: close\r\n”));
client.print(F(“Content-Type: application/json\r\n”));
client.print(F(“Content-Length: “));
client.print(num);
client.print(F(”\r\n\r\n”));
client.print(varString);
client.print(F(”\r\n”));

SerialMon.print(F("Making request to Ubidots:\n"));
SerialMon.print("POST /api/v1.6/devices/");
SerialMon.print(deviceLabel);
SerialMon.print(" HTTP/1.1\r\n");
SerialMon.print("Host: ");
SerialMon.print(server);
SerialMon.print("\r\n");
SerialMon.print("X-Auth-Token: ");
SerialMon.print(token);
SerialMon.print("\r\n");
SerialMon.print("Connection: close\r\n");
SerialMon.print("Content-Type: application/json\r\n");
SerialMon.print("Content-Length: ");
SerialMon.print(num);
SerialMon.print("\r\n\r\n");
SerialMon.print(varString);
SerialMon.print("\r\n");

}

Thanks so much for your help!
Cheers
Matt

2

I seemed to have solved this by building a char array, but first converting all the variables from float to char array too.

char chvol1[8], chvol2[8], chave[8],chcsq[3];
int csq = modem.getSignalQuality();
dtostrf(csq, 2, 0, chcsq);
dtostrf(vol1, 7, 2, chvol1); //convery values from float to char array
dtostrf(vol2, 7, 2, chvol2);
dtostrf(ave, 7, 2, chave);
int str_len = Error.length() + 1; //get length of error string
char cherror[str_len];
Error.toCharArray(cherror, str_len);
sprintf(varString,"{“Volume_1”: %s, “Volume_2”: %s, “Average”: %s, “Error”: %s,“Signal”: %s}",chvol1,chvol2,chave,cherror, chcsq);
num = strlen(varString); //return payload length

3

OK, so the above code worked for a while, now it no longer does. What am I missing? Still getting an Error 400.
Here is my request structure:

POST /api/v1.6/devices/Complete_Setup_Test HTTP/1.1
Host: industrial.api.ubidots.com
X-Auth-Token: *******
Connection: close
Content-Type: application/json
Content-Length: 87

{“Volume_1”: 2375.69, “Volume_2”: 2370.30, “Average”: 2372.99, “Error”: 0,“Signal”: 16}

And the Response:
HTTP/1.1 400 Bad Request
Server: nginx
Date: Tue, 02 Jul 2019 17:33:06 GMT
Content-Type: text/html
Content-Length: 166
Connection: close

4

Greetings, you are using a non-valid quotes, this quote “ should be replaced by the standard one ", so your payload should look like the one below:

{"Volume_1": 2375.69, "Volume_2": 2370.30, "Average": 2372.99, "Error": 0,"Signal": 16}

All the best

5

The 400 (Bad Request) status code indicates that the server cannot or will not process the request because the received syntax is invalid, nonsensical, or exceeds some limitation on what the server is willing to process. It means that the request itself has somehow incorrect or corrupted and the server couldn’t understand it. The server is refusing to service the request because the entity of the request is in a format not supported by the requested resource for the requested method . Therefore, it prevents the website from being properly displayed. The main thing to understand is that the 400 Bad Request error is a client-side error. The cause of a 400 error can be a wrongly written URL or a URL that contains unrecognizable characters. Another cause of the error might be an invalid or expired cookie. Also, if you try to upload a file that’s too large. If the server is programmed with a file size limit, then you might encounter a 400 error.