It's kind of strange to jump into this discussion as my first post but oh well here goes...
I remember the first time I wrote a for loop with pwm control and was able to dictate to a fan exactly how fast to turn
and when to speed up or slow down...
I'v never bought a 'shield' actually scratch that, I bought an Ethernet 'shield' and ended up never using it as my first
foray into arduino-dom was with a Teensy and Teensy++ which strictly speaking are not "arduino compatible".
For the fan I used a transistor mediated MOSFET circuit, ah the misery of circuit design, may it fade away
5v? 3.3v? 1.8v?
Some of this strikes me as slightly superficial, I mean personally I want to learn more about electronics, and even
make my own sensors, this use of modules (which is what shields really are anyway) is great for certain things like ethernet or
bluetooth stacks, but beyond that, I really look forward to using the arduino hardware to help me learn more about electronic
circuits. I like hooking up transistors and using analogWrite() to modulate the power to them in order to understand how they
change in response under different voltage and current settings.
The arduino is like a semi-automated "independant variable" which we in the novice rungs of electronics so often need when troubleshooting
circuits. Before using micro-controllers the best I could hope for when creating a sweep signal was an oscillating 555 which required knowledge of
capacitor to transistor dynamics which I did not have and am still building up.
I have a strange feeling that the 'shield' moniker is not an accidental nomenclature, I have a suspicion that the very word is rife with meaning as it
applies to electronics... Here is a piece of equipment that will 'shield' the user from the details of the electronic circuit. If I'm wrong then I would like
to know why that particular word was used. I like the term "breakout board" or "module", but in the end frankly I don't care about the "compatibility issue"
because my aim personally is to learn how to convert signals from 5v to 3.3v to 1.8v and back again, and the arduino environment gives me just enough
insulation from the horribly unforgiving world of embedded systems so that I still want to explore circuit dynamics.
I think the compatibility issue is more of a concern for those people who view the arduino platform and it's add-ons the way PC and Mac users view their own
platforms. Speaking for my own interests though, I like] the fact that I'm exploring the world of ADCs and DACs and at least asking the questions necessary to understand how to interface a hardware ADC to an arduino, I like the details, it's exciting, and empowering.
My predominant hope with the Due is speed, sheer speed of calculation and a ton of inputs and outputs, I tend to like sensors, LOTS of sensors.
Applications?
I want to play with laser-range finding, no not using a 'shield', but I actually want to get messy with the diode assemblies and phototransistor arrays.
Someone mentioned realtime spectrum analysis, yeah that sounds interesting too.
At the end of the day I don't view the arduino as an 'end' in and of itself like some sort of product to be QC'd to satisfaction...
I view it as a stepping stone into the world of electronics, and a "back door" way of accessing the kinds of knowledge and technology that heretofore
would have required years of study at an engineering school. I don't mind the years of "self-study", but the electronics portion of the gauntlet is just
too hard, and also too basic to be fun... I mean 555's and transistors? That's like living life at the amoeba level, while trying to evolve towards a four
legged mammal... The arduino makes this dip into the austere, spartan, mind numbingly boring world of electronic components... bearable, and dare
I say even 'fun'...
I have a feeling that the limitations I face are mostly knowledge-based limitations. i.e. That the right algorithms coupled with the right signal conditioning would enable some really cool applications even with the current crop of atmel MCUs, to say nothing of the Maple...Mmmmm.
Raspberry Pi? Talk about a confluence of technologies sounding like a breakfast spread. I see the Raspberry Pi as an awesome secondary processing
node for the primary sensor data acquirable with the lower level MCUs...
Something involving cars... and a "radar-like" capability in 360 degrees Hmmmm, yeah I have a lot of learning to do.
Anyway, that's my two cents...