How do you creat music triggered by opening the card

[tparr711]

Hey, I am just curious if anyone knows how to make something similar to a musical card? I was looking at a few cards in the store but none have a song I would want on them. Also it would be nice to know so I could apply it to other things such as when someone opens a cabinet. Not real sure what forum this goes in, so if it is improperly placed forgive me. Any feedback would be helpful. Thank You.

 

[VEBill]

You're referring to Musical Greeting Cards.

They're preprogrammed ASICS.

You'd have to do something with a small uC with sufficient memory. You'd only need a couple of I/O pins; use PWM for the audio out. Using a small MIDI engine (or equivalent), the filesize for the song would be much reduced as compared to a simple .wav file; but a .wav file would be more flexible.

For a one-off experiment, there are 'voice recording' kits available. They're a couple of square inches in size, and cost maybe US$20.

 

[Comcokid]

Greeting cards use a small custom chip that is ROMed with the tune and plays through a small piezo speaker. The tunes used are typically ones that have no active copyrights.
There are sound recording IC and other devices, and you could probably use one to record a particular song. I quickly found the following kit on the web that records 20 seconds of sound.

http://www.electrokits.com/electronics/audio-sound/9.htm

I also seen keychain-type gizmos that use a piezo as both a mic and speaker to record a few seconds of voice. You might look for thoses as well.

 

[TurboXS]

Just as Comcokid suggested.

A while ago I used one of these;

http://www.jaycar.com.au/productVie...d2=&pageNumber=&priceMin=&priceMax=&SUBCATID=

as a one-off.

Just recorded the sound I wanted and rewired the switches to suit. Worked fine and was quick to do.

 

[Comcokid]

I tripped across some of these devices in an unrelated search, so I thought I would look up this older post.

Nippon Precision Circuits (NPC) makes a variety of these devices. Some are in die form, some in packages. Most have preprogrammed tunes. One device allows a controller to load the SRAM of the chip so a customized song could be created.

See:

http://www.npcamerica.com/product.htm

and click on the "Tone generation/Melody IC's" link.