JS supports integers; it just doesn't have an integer type so you can't always store, operate, etc on them efficiently (though a smart engine can do some of that for you). It has bitwise manipulation operations which treat the Number as a 32 bit int. There are also Typed Arrays which make it easier to work on raw binary data. Though yes, it can occasionally get a little finicky trying to interface a high level dynamic language with lower level stuff.

Anyway, for this I'm sure there will be a lot of libraries that handle that for you and expose a fairly high level api; like the blinking led in the example.