No response after sending Initialization Setup

After making a tcp socket connection to Plotly (IP : I don’t get any response when sending my username / key / token listed on my settings page:

POST /clientresp HTTP/1.1  
User-Agent: MSP430F5529/0.5.1    
Content-Length: 268
version=2.2&origin=plot&platform=Stellaris&un=username12&key=1234567890&args=[{"y": [], "x": [], "type": "scatter", "stream": {"token":    "0987654321", "maxpoints": 7200}}]&kwargs={"fileopt": "overwrite", "filename": "Element14 Temperature Plot", "world_readable": true}

After a while of waiting, I send it some test data but no response either:


I’m doing this using an MSP430 microcontroller, but to debug, the same thing happens when using a PC running Hercules. I’ve double checked the 10-digit username/key/token spelling and that each of the 5 lines above is sent with a carriage-return/line-feed at the end (\r\n), so not sure what could be wrong with what I’m transmitting.

Is there a simpler/smaller string I could try to see where it goes wrong?

What URL should I be looking at to see if the data is getting posted? Perhaps everything is ok, but no server response?