Any people with iTracker RAK8212 here?

Ahh - yes, Promises can be a bit crazy... You can do something like this (this one just checks BTN1 and resolves if it was pressed when it checked, or times out after a while):

// Promise.resolve() is just to get it started - in reality you'd stick this on the
// end of the promise chain
Promise.resolve().then(function() { 
  return new Promise(function(resolve, reject) {
    var n = 20;
    var i = setInterval(function() {
      console.log("Checking BTN1 "+n+"/20...");
      if (BTN1.read()) {
        clearInterval(i);
        resolve();
      }
      if (n-- <= 0) {
        clearInterval(i);
        reject("Timeout!");
      }
    }, 1000);
  });  
}).then(function() {
  console.log("Done!");
});

Basically when you do stuff like this you want to return a promise immediately (which you do with new Promise) then you execute your code in the function inside new Promise(function(..) where you have two arguments you can call - one to resolve it if everything went ok, and one to reject if it's all gone wrong and you want to bail out :)