Where's the rub?

The first thing that comes to mind is the message you are trying to send via SMS. Have you tried something less complex like Marry has a little lamb? As you are trying to send a JS object via ASCII channel you should probably escape it beforehand like this data: {"lat": 14.640284, "lon":121.078195}.

BTW would you be so nice and help me to wire up the SMS plugin? My attempts to use the plugin (to receive the SMS) ended in spectacular failure.