GSM2 Click Interfacing.

Thanks for all the help on this guys.

I have just wired up the GSM module to a 1000mAh battery with 3A output and only using the Espruino for reading the RX and TX lines. The text messages now come through it seems every time and the AT commands are more responsive.

I am still getting some spurious data coming through the lines but not half as bad as before here is what I am seeing:

=undefined
 _____                 _ 
|   __|___ ___ ___ _ _|_|___ ___ 
|   __|_ -| . |  _| | | |   | . |
|_____|___|  _|_| |___|_|_|_|___|
          |_| http://espruino.com
 1v52 Copyright 2014 G.Williams
>>echo(0);
GSM Starting..
=undefined
AT+CMGF=1
>
OK
AT+IPR=9600
OK
>Serial1.print("AT+CMGS=\"07817xxxxx\"\r");
=undefined
AT+CMGS="07817xxxxxx"
>
>Serial1.print("testing a message" + "\x1a");
=undefined
 ÿÿÿýýÿÿÿòÿïÿÿÿþûÿÿþýÿûÿýýìÿÿÿþÿÿöóýÿÿøüóüÿÿþûÿýýÿûýÿýûÿùûÿúÿû÷testing a messageÿÿÿÿÿÿýÿýýÿÿÿÿûþÿ
+CMGS: 9
>
OK
> 

The text message I receive is:

 ÿÿÿýýÿÿÿòÿïÿÿÿþûÿÿþýÿûÿýýìÿÿÿþÿÿöóýÿÿøüóüÿÿþûÿýýÿûýÿýûÿùûÿúÿû÷testing a message

Subsequent messages are better:

>Serial1.print("testing a message again" + "\x1a"); 
=undefined
 testing a message againÿÿÿÿÿÿÿÿÿÿÿþÿÿ÷ÿ

With the message received at the phone being:

testing a message again

Is there a check I can put in place to remove these weird characters?

Currently using:

function handler(c){
  ms=ms+c;
  if (c=='\r' || c=="\n" || c==">"){
    console.log(ms);
    ms="";
  }
}

Serial1.onData(function (d) {handler(d.data);});

For serial data handling.

For anyone else with similar issues to this thread, power was the killer for me it seems.