Amazing chinese technology surpasses MEMS accelerometers

We're super impressed by this piece of Chinese high technology. For a near-zero price they obtained "tap detection" typical of MEMS micromachined accelerometers!!!



Let's go with order. We're trying to find a fish to become the official DreamLover Labs fish. No we haven't gone totally insane. We need to take some nice waterproofing pictures real soon so we want a fish and a fish tank. We didn't find any fish around here (perhaps because they all get eaten!) - but we did find a silly yellow super-stretchable silicone thing with a ball inside that shines real bright when shaken. That didn't turn out to be a very good purchase so we decided to euthanize it and find out what the circuit was like. Inside there was a plastic ball, which we destroyed. Inside, this little circuit.

Amazing. Look at that very soft spring. When you tap/shake the ball, the spring makes physical contact with the PCB pad underneath and closes a circuit! This is "tap detection" which our accelerometer needs 120 samples per second to achieve. It also uses up 0.3mA which is as much current as the rest of our product (RF module switching on and off etc).

Since we're waiting for payment gateways and rubber stuff anyway, we'll look into sourcing these springs. Not even sure what the material is. But they're quire fantastic. Quiescent current consumption for the Penis Slap Amplifier will go to ZERO. The spring can even be fine tuned! The closer it is to the pad, the more responsive it will be to taps. So you can solder it at a particular angle with respect to the pcb as needed. End users can even adjust this angle after the fact by deforming it slightly, as needed.

If we can source the springs (and find space on the PCB) we'll use them for the PSA and avoid the problem we were having with accelerometer current consumption. We'll still use the accelerometer for a variety of reasons but we will be able to set the samples/second to a much lower value and save a bunch of current! It's just amazing that 120 samples a second, micromachined MEMS technology and all that stuff can be replaced by a 0.00001 $ spring. :)

Chinese high technology!

Comments

By dreamloverlabs at 2010-04-01 11:49:17 Reply

Seems this will be hard to add at this stage without lots of tweaking. Placing the spring at the right angle is going to be tricky and repeatability is low. If an error is made while soldering or the screw gets deformed and touches the pad permanently the unit will zap away mercilessly. Considering safety etc. this doesn't seem like the way to go. Very clever though.