So, I’ve received my $9 Arduino, which included all the perks from Borderless Electronics (some resistors, LEDs, push buttons, and some other stuff).
First and foremost, I’ve got Arduino up and running in literally 10 minutes, most time spent on downloading and installing the programming tool.
Connected it to an LED and a button, wrote a simple program, and all worked right away.
But here is the best part about it: it uses USB (USB-A to micro-B) as its programming connection, and it can feed right of it! Meaning, it should work with any standard cell phone 5V power supply. With the cost down to $9, standard power connector, flexibility in power supply (from 5V and up to 12V, it seems), twice smaller than Raspberry/Pi (actually R/Pi is much bigger than a “credit card size”) – this sounds like a serious competitor to the platforms I mentioned before (mainly PICAXE). Man, that micro-B USB connector, which serves as a programming port and also 5V power supply – that is totally awesome. This is how things should work, indeed!
I was urging to put my Arduino to work, so I started to think about a practical project to use it.
I’ve been planning some automated light switches around my house, and I wanted it to be tunable for different places in my house, so didn’t really want to go with standard outdoor motion sensors – those are neither cheap or tunable.
At the same time Roger has drawn my attention to the possibility of programming smaller ATtiny chips with the same Arduino code (Youtube: http://www.youtube.com/watch?v=30rPt802n1k, but you can get the idea faster from here: http://hlt.media.mit.edu/?p=1695). In a nutshell, you use Arduino board as a programmer for ATtiny chips. (You can buy a separate programmer, too – but it sounds less cool, I guess.) Aha, this is much better than using my all nice and flexible and powerful Arduino Leonardo for 2 to 4 pin project.
ATtiny85 can be compared to PICAXE-08M2, I guess. I was told ATtiny85 can be found for below $1, while 082M costs almost $3 ($2.66 from Sparkfun if you buy 10 or more… and I’m just about to buy 10 of either for my light automation project). Features like I2C and serial port are nice to have (for debugging), but not really important for my project. What is important though is the ability of on-board re-programming… for some reason I just like the idea.
Well, adding programming connector 1) adds some hassle to the design process (I hate connectors), and 2) takes 4 pins out of the game (or I will have to add some switches for Programming vs Operation mode). PICAXE, on the other hand, has pre-loaded firmware, which uses serial communication for re-programming. I could go with 8 pin PICAXE, but would have to take 14-pin ATtiny, i.e. ATtiny44 or ATtiny84. Also, I will have to design all the connectors myself, because there’s no standard (or at least I’m not aware of one) for ATtiny programming connector. Furthermore, I’d have to either buy a programmer or to create some connector to use one of my Leonardo boards… a lot of effort spent on boring things. Hmm… PICAXE definitely wins on-board programming contest.
Another thing is, Arduino was made a standard board with connectors and stuff because it is, well, much easier to work with something well standardized. PICAXE connectors are standardized as well, and the programming circuit consists of 2 resistors. I’m just too lazy now to design something similar for ATtiny (and frankly, I really like the idea of on-board programming interface; as a software developer I hardly can think about designing something I cannot re-program later on).
Although the difference between $2.66 PICAXE and $1 ATtiny (representing Arduino) is not really significant anymore (it’s not like one of those old $20 Arduino boards), it is not really important for a hobby project… convenience is. And for real world production, like I said before, I’d rather use that dirt-cheap bare PIC. Boomer! I’m ending up with my old favorite PICAXE… but I’m planning on using Arduino for something more complicated than that… maybe, some robotic project, or more complicated automation, like watering system in my garden, or maybe some project with a display and some buttons and such. We’ll see.