• Just to throw in my 2c worth I've never used either of those particular dev boards, but at $100 -$150 they will save you a world of pain unless you're very experienced with RF (I'm not) and at least you know you're starting with known working hardware. I see the CC2540 is only a few dollars in volume, much cheaper than years ago when I was looking and went down the custom protocol path for a particular project. – PeterJ Feb 6 '13 at 11:24