Communicating with multiple Espruino devices

@Gordon

We have been experimenting with multiple slaves using the information above but are unable to get the response working with more than one. (Same issue @user66543 was having)

The strange thing is whenever uncomment the pinMode function communication does not work at all. Is this the correct way to use on init below?

E.setBootCode("
E.on('init', function() { 
  echo(0);
  //pinMode(B6, 'af_opendrain');
  });
var ID=getSerial();
function xgmSlave(ledid,onoff)
 {
  digitalWrite(ledid,onoff);
 };
", true);