Since the last time I posted my work on the Arduino Uno in Sketchup Project, I have started using a magnifying glass. Lo, the minuses in front of the digital pinout numbers turned out to be tildes (ie, ‘~’ –which, with the quote marks, looks like an emoticon of a dolphin face with a wry smile!).

So why are there minuses or tildes on the Arduino in the first place, you ask? Because they indicate PWM (‘pulse width modulation’) programmable pinouts which can be used to control the brightness of LEDs among other things. It’s all explained in pp. 56-62 of Getting Started with Arduino. However, the book does not mention that 3, 5, and 6 are also PWM according to the markings on the Uno, which indicates to me that making these pins PWM was an upgrade for the Uno that came after the book was published.

I’m sure there are old Arduino hands who are thinking, “Sheesh, this guy is like a super newbie.” Yeah, well, that’s how come there’s Zero after Engineer. Anyhow, if you’re a newbie too then maybe it’s best to follow along with another newbie, who won’t emit disdain if you don’t know what a d0/47/25V is, which I don’t (yet).

Anyhow, I have to say that I’ve learned almost as much about the Arduino by studying the layout in Sketchup as I did in reading the book. In that sense, 3D modeling is like a hands-on experience!

(SIDE NOTE: I have uploaded uracil to the Google 3D Warehouse. Link is here. Strangely enough, a search on ‘uracil’ shows that there is a username ‘uracil.’ I won’t ask.)