Arduino/Piezzo connections

Meanwhile there should be more developments in the programming stage for the Pure Data patch and the Arduino connections.
For the record here is an image of the way to connect the Piezzo to the Arduino.

Dumm conclusions

I have been struggling to get my two XBee pro's to communicate with each other. However there has been no progress in that and I couldn't figure out why.
Do you know when you think you know something about something and when you're reading about it you kind of skip some parts just because you think you already know what's coming there!?
Well, this was the case... I was thinking I knew enough already about the XBee to go straight to the programming stage... However, just because I have the XBee pro 900 digimesh RP-SMA that wasn't so right.
The reason is simple: turns out that RP-SMA is a connector for the actual antenna. Needless to say that without an antenna there is no communication!

"The UFL and RP-SMA options are just connectors, they require an antenna tuned to the correct frequency and with the proper connector in order to function!" http://www.ladyada.net/make/xbee/modules.html

Next step: buy a couple of antennas!

XBee pro 900 digimesh RP-SMA

Finally I got back from a big absence in the development of Cycle Sound.
Once I made some progress in different parts of the project, other priorities took place.
The parts I worked were:
building the handlebar that supports the drumpad; build the electronics of the drumpad; make the connections to the Arduino; program the Pure Data patch to get the drumpad signal and send it to an external VST (in this case for experimenting I'm using FM8 from Native Instruments).
Each of these parts are not complete but ready for experimental stage. However there is still one part missing so that experimental stage can take place and that is what was I most recently working on: the XBee communication. This is the device that allows the RF transmission of data from the Drumpad -> Arduino to the Station that will read and play the bicycle's signal.
Therefore, the complete diagram for the signal's path is:
Drumpad -> Arduino -> XBeeShield -> XBee --- XBee -> XBee Explorer -> Computer (MacBookPro).

However, the progress made on the XBee's is still not enough for the required task.
Two major issues are making it go slower than expected: I only have one XBee Explorer so I had to find a way of working on both XBee's at the same time using an Arduino and a XBeeShield; the X-CTU software for programming the XBee's is a windows only platform. Making me use a Virtual Machine that brought problems of it's own to the equation.
In the end I was able to program the XBee modules without being able to get them to communicate with each other. Which means I'm only half way through this step.
However, hopefully, as soon as I get these two modules communicating I'll be able to experiment the whole setup. After this I will actually get the bicycle to mount everything on and take the first outdoors trial.