We all know by design theory that four-legged stool is more stabile than three-legged one. But why four-legged stool is always wobbly? Here is the reason why. No one nor machine can actually make a perfect four-legged stool with the exact same length of legs. Reason number two, there is no such thing as perfectly even surface or floor to put the perfect four-legged stool on. Hmmm... what does a four-legged stool have anything to do with SnapBloks? Glad you asked! Remember our first project log about serializer and deserializer? We need two contacts for powering and two contacts for serial data in and out. That is a total of four contacts! No matter how perfect we mounted the magnets on board, the Blok would end up wobbly. It means that we would get wobbly/unstable power or data transmission with four contact points. That is not good at all!

So what about three-legged stool? Look at a tripod. A tripod, basically, is similar to a three-legged stool. It is very stabile for uneven surface. With this kind of stability, we can make sure that SnapBloks would not experience any unstable or intermittent connection. But wait, how would we reduce the number of contacts from four to three? The simple answer is, we architect the system to send and receive data on one wire only. As a compromise, we have to accept the fact that we can't send serial data in full-duplex mode.

Alright, we can live with only three contacts, half-duplex it is. And that is how we came up with three magnetic contacts solution on SnapBloks, from the very first design started at about two years ago and we keep it the same until today.