I am trying to use the low-level TCP/IP SMS-over-IP functionality with my Konekt SIM. I can make normal HTTP requests and I have independently tested the TCP connection using ngrok, so I think the network connection itself is OK.
I am opening a TCP connection, sending the string “SXXXXYYYY+447999123456 Test SMS\n\n”, where:
XXXX is my four-character ID
YYYY is my four-character key
+44 is the UK country code
7999123456 is the destination mobile number with leading zero removed
Test SMS is the actual message
\n\n is two newlines as specified in the API documentation.
I’m not receiving anything on the destination mobile. Can anyone suggest what I’m doing wrong?
Adding the space didn’t change anything. Just to clarify, I am doing the following:
Opening a TCP connection to 23.253.146.203 port 9999
Sending the string
Waiting for 2-byte reply
Closing connection
The destination phone doesn’t receive anything and I don’t receive a reply over the TCP connection at step 3.
I’m using an Arduino Uno with a SIM800H board. The software debugging outputs says that the TCP connection is being made and that the data is being sent.
Does this look correct? I’m aiming to get a Konekt SIM working from as low resource a controller as possible, so having being able to use the TCP connection is important.