Sunday: Pinning Down The Makey Makey

As of Friday, allocation of the pins on the MaKey MaKey was going rather well, then there was a bit of a hiccup. If we look at the top row of connectors on the MaKey MaKey itself, there are three pins called D14, D15 and D16...

At first we thought that these pins were just extras that were not used by the MaKey MaKey in the default configuration. However, sifting through some of the internet forums revealed that pin D15 is in fact linked to the left arrow key. So, it doesn't matter if we trigger the left arrow key on the board or pin D15, both will output the same command. Great, this means one less potential alligator clip in the setup and therefore a little less clutter in the box. But, now  there is a new problem. In the current prototype for the Chord Board, the faceplate that provided the user input was set up as a seven by three button array. The top row of buttons would each trigger a chord responding to one of the seven diatonic chords in the scale. The second row of buttons were supposed to trigger the first inversions of the chords in their respective columns and the third row was meant for triggering the second inversions. This whole setup requires a minimum of twenty one inputs to work as we planned it to. Now it seems that we only have twenty pins and possibly as few as eighteen if there is not a workaround for the doubled pins on the top header. 

So, in order to make this project work, there are two possible solutions. The first one is to dig through the arduino code and see if it is possible to decouple pin D15 from the left arrow key as well as activating pins D14 and D16 to receive input, thus restoring the twenty one necessary inputs. Provided that the pins can be reassigned, the project would be back on track. Then I remembered that this project needs ideally to be executed with as little effort by the end user as possible, at least on the software side of things. By this I mean, the previous fix could work fine, but we don't think that our target creators (the teachers and young students) would want to have to load a modified firmware file into their units before putting the project together, it is always possible that files could become corrupted and it detracts from the plug-and-play allure that comes with the MaKey MaKey itself. 

The second solution is a lot simpler, Graham and I decided that we could instead reduce the number of necessary inputs to ten. This is less than half of what we previously thought we needed. The updated design of the Chord Board would be significantly simplified. Instead of having two rows of seven buttons triggering first and second inversion chords, we have replaced the two rows with only two singular buttons! Now we can simply jump back into scratch and turn the two buttons into "shift" or "modifier" keys. So, if one wants to hear C Major in first inversion, the new command would be to press both the "c major" button and the "first inversion" button at the same time. This is simple enough to make work in scratch and it will also reduce the time of construction and setup for the end user. I'd say that this could very well be the next revision of the MaKey MaKey Chord Board!

That's all for now, back to to work tomorrow, so have a nice remainder of the weekend!

P.S. Here is a preliminary design of the Chord Board itself, using the original MaKey MaKey box as the container for the enclosure!