quote:
Originally posted by sandysimon:
Has anyone ever bought some of those inexpensive sound chips (that are used in some greeting cards), and programmed them for sounds to be made when various events occur on the layout?
With chips, particularly those used in recordable greeting cards, the signal level is too low for background in an O-gauge layout. So you'll need to amplify it. Also, I think you'll find the audio quality somewhat lacking.
Instead, I suggest trying a low-end MP3 player. There are small MP3 players with built-in speakers ($20). Or amplify the earbud signal from the pack-of-gum sized players ($10 or less) which you'd have to do anyway with a chip. MP3 sound quality is very good. Also, you can download free MP3 sound effect and digitally edit and store them in a player whereas you'd likely have to play and record them analog into a DIY sound chip. Even the lowest-end player gives hours or days of sound rather than seconds or a few minutes max with a chip. Here's one I bought surplus for $5 but they are long obsolete.
I think you can go wild synchronizing lights and sounds with an Arduino. The players I've tinkered with are quite simple. If you store multiple MP3 sound clips, the player will play them in order with the first file directory name played first. So if your sound clips are a.mp3, b.mp3, c.mp3, etc., then a.mp3 is played first when you power it on. But if you want to access the next clip, then press the Fast-Fwd button and it skips to the next file. So an Arduino can effectively access a random sound clip by pulsing the FF button the correct number of times. So you end up with a accessory sound jukebox. And then since MP3 sounds can be stereo, you can create interesting directional effects when synchronized with lighting.
If you go this route and want to discuss the nuts-and-bolts of how to power MP3 players or emulate switch closures using Shift register outputs, I'd pose this as an Electrical Forum problem - the details can get a bit 'nerdy'.