So what do i mean by expandable? Basically the idea is that I would like the cheapest possible way to be able to create a circuit that I could chain sub circuits too (those are the 2 sub circuits in the video). After lots of trial and error, I was able to put on my crafty hat to make these darn electrons work the way I wanted them too.
In the accompanying video, I give a quick run through of how the circuit works. Essentially, the main goal that I was able to achieve was that I would be able to clone one the inner circuits and add it right in the middle. All I would need to do is connect them to the 2 digital pins, 2 analog pins, one ground, and one 5V series, and it should work without any additional rewiring (although the idea is to make the sub circuits slightly different in their interaction, yet the same in their communication), asides from programing the EEPROM (I used the 24LC256 from SparkFun for $1.95) to contain a unique identifier. The secret to success…diodes..lots of them.
I based my code on a great snippet of code to help me get the I2C communication working on my EEPROMs. I also checked out a helpful tutorial which also helped me out substantially.
One quick tip: Keep in mind that Arduino has an EEPROM mounted on the chip. I intially made the silly mistake of using the EEPROM code that is found on the Arduino tutorial page. This code was reading and writing data on my Arduino’s board mounted EEPROM, which i quickly realized once I realized that the unique data I was writing on each external EEPROM chip did not seem to be working properly.
So why go through all this extra effort? Basically there are two reasons.
1) allowing a person to customize and interchange their toy gives them an added sense of ownership, and taps into an emotional type of attachment.
2) it is pretty easy to come up with a ways of taking the ideas behind this circuit, and give very young children the ability to construct abstract concepts such as flow. This in turn makes this simple interaction material a digital manipulative with extraordinary educational benefit.
One of my points of inspiration was MIT’s Mitchel Resnic’s Programmable Beads , and other work with digital manipulative that I’ve spoken about on other posts.
Onto phase 2…
Here is a video of Mitch Resnick speaking about his Lifelong Kindergarten group at the MIT Media Lab
