metronome from CMOS logic?

[egasimus]

I've been contemplating this for a while, as I've been needing a portable metronome which doesn't sound as annoying as the one built into REAPER. I have no grudge with it, really, but my wife is really bugged by it. She says it reminds her of the sound the Octopus from Disney's Peter Pan made when walking, and, although I've never heard how that sounds, I must admit there just might be a resemblance.

Of course, I could easily do this with an ATtiny2313, and maybe even cram some basic audio BPM detection into it. Would be cheaper, too - that's a major concern for me. But there's something compelling in building stuff only out of logic ICs. So why not build a metronome with a display only out of 4000 series chips? I'm not really sure about how it would work, but I'm pretty certain about some would-be problems.

1. Input - I don't think a PC keyboard-like repeat action would be easy to implement, so that leaves me with a bunch of switches like +1bpm, +10bpm, +100bpm, etc. - unless I figure out how to interface a rotary encoder with CMOS logic, and I don't have a model of one in my simulation software, either. Can anyone send a Proteus model of an encoder my way?
2. Tap tempo - this depends on how the metronome would actually be implemented. Maybe would be feasible, maybe not.
3. Time signatures - of course, this is a problem only if it actually plays different sounds on different beats.
more to come...

Any ideas?

[pjwhite]

You could make a very simple metronome with a 555 timer chip and a pot.  When you start adding displays, encoders, tap tempo or other such features, a microprocessor is almost certainly the best way to go.

[Hides-His-Eyes]

I'd go with the chip myself. a tap tempo metronome would be great, and you'd have much better timing accuracy with a pic than with an RC timer.

[scratch]

egasimus, check this out ...

http://www.diy-electronic-projects.com/p189-Precision-Metronome-and-Pitch-generator

I've been wanting to build this myself, but have not gotten around to it yet. One could replace the thumbwheel switches with up/down decade counters attached to display drivers. Crystal based so does not have the drift issues of an RC clock.

[egasimus]

Looks great! Thanks, this will be a fun project.

[toneman]

Anderton Circuits:

HeadPhone Amp from EPFM
http://img126.imageshack.us/my.php?imag ... amphs3.gif

Project #1 Preamp http://img61.imageshack.us/my.php?image ... ampgj0.gif

Project #2 Metronome http://img61.imageshack.us/my.php?image ... omeuv6.gif

links from:
http://freestompboxes.org/viewtopic.php?f=19&t=498

[AdamM]

can't you just reconfigure the reaper metronome to use different sounds?

[toneman]

try this complete link.....


http://imageshack.us/photo/my-images/61/andertonmetronomeuv6.gif/