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In JavaScript?

It seems I got the endianness wrong, so you can't just do: new Int16Array((new Uint8Array([235, 250,5, 9,253, 21])).buffer)

Instead you need:

var a = [235, 250,5, 9,253, 21];
var d = [(a[0]<<8)|a[1], (a[2]<<8)|a[3], (a[4]<<8)|a[5]];
for (var i=0;i<3;i++) if (d[i]&32768) d[i]-=65536;
// results in d

I guess you're using Java in Android - that code should be pretty easy to convert.

There are other ways of converting numbers from byte arrays (utilities in various different languages), but the code above is pretty universal.