Puck Advertising Private Characteristic and r/w

Ok, so it looks like your first issue (getting the data in a write notification) is sorted?

How do I make the second service with button state?

You just add an extra element to the object. For example:

NRF.setServices({
  "3e440001-f5bb-357d-719d-179272e4d4d9": {
    "3e440002-f5bb-357d-719d-179272e4d4d9": {
      value : [0],
      maxLen : 1,
      writable : true,
      onWrite : function(evt) {      }
    },
    "3e440003-f5bb-357d-719d-179272e4d4d9": {
      value : [0],
      maxLen : 1,
      writable : true,
      onWrite : function(evt) {  }
    }
  }
}, { uart : false });

What you're doing with updateServices looks fine. All I'd say is it's far more efficient to use the same basic UUID and to change the second group of 4 digits as you did in the first example.

I just tried this code and it works fine:

NRF.setServices({
 "3e440001-f5bb-357d-719d-179272e4d4d9": {
   "3e440003-f5bb-357d-719d-179272e4d4d9": {
      value : 0,
      writable : false,
      notify:true
    }
  }
});

var n=1;
setWatch(function() {
  NRF.updateServices({
    "3e440001-f5bb-357d-719d-179272e4d4d9": {
      "3e440003-f5bb-357d-719d-179272e4d4d9": {
        value : n++,
        notify: true
      }
    }
  });
}, BTN1, {repeat:true,edge:"rising"});