Breadboards are for fast little circuits, Arduino for Makers, and.. 42M3? For System Designers!
Well, there’s the headline and the truth; going with the latter, there’s no other reason, apart from the fact that I need a lot of “little electronic bricks” to build much more complex boards, that I’m defining this standard, that’s why I’m calling it “personal”, I’m the one using it, but there’s a reason behind its specifications.
42M3 means to be able to design little circuits that can be used stand-alone or with other circuits to build more complex systems, that’s it.
The goal with a small PCB is to keep circuits and applications simple, manufacturable, upgradable and cheap to panelize, so that I can manufacture 20+ PCB at the same time, with different functionalities, and with a lower final cost per single 42M3 module.
For those of you who have read “Sprint” by Jake Knapp and some other Agile books (or maybe use Trello.com for their projects) this should sound familiar, and it is: “cut down what you want to do into simple, self-sustainable steps, so that you can describe them on a single Post-it” (I’m paraphrasing here).
The conclusion is a squared PCB, 42mm wide, with 4x M3 holes (Metric standard, I’m sorry, but after the fall of the Roman Empire I just can’t stand Imperial units).
Why not using Arduino? The footprint is too big, I do not like to have a uniform pinout for every module (that’s a waste of space and material if you’re not using all those pins) and to work with higher voltages and currents would be very welcome (oh, and it’s cheaper).