Something's very wrong if you're trying to use Serial3. What about:
var at;
console.log("Turning Cell on");
require("iTracker").setCellOn(true, function(usart) {
console.log("Cell now on");
at = require("AT").connect(usart);
at.cmd("AT+CBC\r\n",1000,function cb(d) {
if (d=="AT+CBC") return cb;
if (d!="OK") console.log("CBC is "+d);
});
});
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
Something's very wrong if you're trying to use Serial3. What about: