Grove are a fun concept, lots of cheap, little sensors, buttons, etc. on little PCBs with a universal 4 wire connector system (e.g. gnd, vcc, rx, tx or gnd, vcc, sda, scl). Making projects becomes more like lego but it's a bit less heavyweight than the "shields" or "hats" ideas, and a lot cheaper! I got a mixed bag recently, about £12 worth, plus a "seeduino", which is Seeed Studios' *duino clone. The price quite recently dropped from something like $19 to something like $6.90! To be honest, most retailers, like the one I went to, are still selling nearer the old price, but I guess you can't blame them if that's what they paid for the stock. I think I forked out £18 in the end, plus the 12 for bits, making about 30... plus postage, etc. I got: An IR distance interrupter - single bit detects if a person (or thing) gets close, obviously great for robotics, although many other applications PIR (passive IR) motion detector - security li...
