Difference between revisions of "Automated Xylophone"

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=== Connecting the Keypad ===
=== Connecting the Keypad ===
== Code ==
== Code ==
<br>
===Multiplexing===
===Multiplexing===
<br>
<br>
=== Commented Code ===
=== Commented Code ===
== Results and Next Steps ==
== Results and Next Steps ==

Revision as of 05:44, 18 March 2009

Team Members

[Include team picture]

Brandon Robins (Senior in Mechanical Engineering and Music Performance, Northwestern University)
Neil Tiwari (Masters Student in Biomedical Engineering and Kind of a Big Deal, Northwestern University)
Jenny Yong (Senior in Mechanical Engineering, Northwestern University)


Overview

The goal of this project was to have a user input a sequence of notes and have a PIC controlled solenoid sytem hit a xylophone to generate tones. Our automated xylophone operates in two settings -- real time mode and playback mode. In real time mode, the user inputs notes using the keypad and they get played back on the xylophone instantaneously. In playback mode, a user can use the keypad and LCD screen to verify and store over 250 notes in sequence including rests to be played back on the xylophone at a later time.

Operating the Automated Xylophone

[Include picture for description of keypad] The user interface includes a keypad containing 16 buttons, arranged as seen above.

Real Time Mode

In Real Time Mode, buttons 1-8 are used to determine xylophone note. As soon as a button is depressed, it will immediately trigger a solenoid to play the chosen note.

Playback Mode

To enter playback programming mode, you hit button 16 -- the edit button. Playback programming mode allows you to store 256 notes, including rests, per block. Once in edit mode, you have access to buttons 1-12. As in Real Time Mode, buttons 1-8 still determine which note should be played. Buttons 9 and 10 will adjust the note duration to shorter and longer respectively. Buttons 11 and 12 will adjust the which sequential number is being programmed. Button 11 will lower the note number, while button 12 will increase the note number. Rests can be programmed using button <n>. To enter and store a note, you use the enter button, button <m>. Once you have finished entering the string of notes you would like to store, you hit button <o>.

To listen to the stored song, you hit button 16, the edit button again.

Parts List

Coming soon . . .

Mechanical Design

[Include pictures of interior of wooden casing]

Mechanical Interface

Our mechanical design was fairly simple and straightforward. We needed to determine the optimal way for the solenoids to hit the xylophone keys, and a way to support them in that position. Initially, we found it to be most intuitive for the solenoids to strike downward onto the keys. However, that design would require us to keep the solenoids powered during rest. Therefore, we choose to have our solenoids strike from below the xylophone which allows us to keep them powered off while inactive.

One feature of our mechanical design is that with the xylophone chosen as the bars are hit, the piano keys depress. This design creates the appearance of a phantom piano player.

Solenoid Positioning

To improve aesthetics and support the xylophone at the proper height, we created a wooden housing for the solenoids. Within the housing, our solenoids rest on an aluminum beam which hold them at the appropriate height. On our aluminum beam, we have a ladder-like structure made of foam core to hold the solenoids in place.

Tape was also placed around the piston of the solenoids, as can be seen in the photos. This technique was a temporary solution to prevent the solenoids from banging on the aluminum beam and keep them at an operable height once powered at 12 V. The xylophone is placed on top of the wooden housing with the bars properly aligned with the solenoids.

Electrical Design

[Insert picture of circuit and circuit diagram]

Powering the Solenoids


Connecting the LCD


Connecting the Keypad

Code

Multiplexing

Commented Code

Results and Next Steps

References