Long life logger using eeprom and bluetooth

OK, I have returned to this project finally.

The GPS unit (ublox Neo-6m-0-001) works fine, takes about a minute before it gets a "fix".

Got BT working, so I can read the SD card remotely.

The problem I am having now is understanding how to turn off the GPS unit, I mean it needs to be powered off for 4 hours until its next wake up call. I am guessing that cold starting the GPS will consume far less power than keeping it powered on (warm?).

This is inside a setInterval() loop - I was thinking of setting a flag to break myself out of the setInterval() loop, but now am doubting that is the correct way to think about this.

bGotFix = 0;
  
  var gps = require("GPS").connect(Serial4, function(data){
    
    if(data.fix == 1) {
// todo this will be logged to sd card
       console.log(data.time, data,lat, data.lon);
       bGotFix = 1;
    } else {
// debug
       console.log('no fix yet');
    }
    
  });

Traditionally I'd check data.fix is true, stop the interval code, but how to turn off the GPS? Or do I need to?