Exploring adding setWatch/clearWatch (interrupt handling) to MCP23017 (MCP2308) Portexpander Ports

Ahh - typeof D0 is actually "number" - so I meant actually using it to check whether someone had fed an object in...

A bit like:

(function() {
 var _setWatch = setWatch;
 setWatch = function(a,pin,b) { 
   if ("object"==typeof pin && pin.setWatch)
     pin.setWatch(a,b);
   else
    _setWatch(a,pin,b); 
 };
})()