conv.js

function h2b(hexin){
  return parseInt(hexin, 10).toString(2);
}
//from http://stackoverflow.com/a/12987042
function d2h(n){return n.toString(16).toUpperCase()}

function conv(hexin){
  console.log('0x'+d2h(hexin)+':'+h2b(hexin));
}
/*
#Example usage
conv(0x1F);
#Example output
0x1F:11111
*/