Music Input

[malc-c]

Thanks for that, but me been a tight ass brit object to having to pay a quid to obtain access to the article... especially when the HEX and ASM are free !!

I did come accross this project, which appears to use the filtered bass to trigger an NE555 to provide the logic pulse to trigger another NE555 which can run as an astable free runner or mono-stable triggered by the music.






The actual chase generator is a 4017 decade counter. ( full project details http://sound.westhost.com/project62b.htm )

I might just try this, however it seems a but of an overkill to use all those op-amps and an NE555 to provide the input into a PIC.... I'll keep googling and yahooing and see what turns up

[Melanie]

An Analogue Comparator allows you to trip your input pin at different voltage levels determined by an internal or external reference. So, if you set your Reference voltage at say 500mV, you can trip the Comparators Output on or off at 500mV rather than the usual trip level for a Digital I/O pin.

By sweeping the Comparators Reference Voltage, you can then use its input as a cheapo ADC. However, the internal Reference in the 16F628 only has two scales of 16 steps, and allowing for a settling time would not be very good for Audio input sampling.

So, in reply to your query, an Analogue COMPARATOR does what it says... it COMPARES your input against a Reference. Whilst an Analogue to Digital CONVERTOR (ADC) will give you a snap-shot of your current Analogue input in Digital form. The two are NOT the same.

The 16F628 has TWO COMPARATORS on-board and NO ADC's. ADCIN only functions with ADC's which is why it's named ADCIN (that what I love about microprocessors, they name everything so obviously!).

[Acetronics2]

but me been a tight ass brit object to having to pay a quid to obtain access to the article... especially when the HEX and ASM are free !!

Let's see how much you hope to save ( let's do the whole count for the project ) ... makes me laugh !!!

mmmh, by the way ... have a look to Freescale MC 3340 P datasheet. An old Elektor ( once more, ... !!! ) summer issue show a really nice application

You'll be more than happy : datasheet is free ...

you fast draw, mmmmh ???

Alain

PS : 5or 8 £ for a pre-programmed basic PIC ( 675,628,84 ...) ... you're joking, I hope !!!

[malc-c]

Melanie,

Thanks for the explanation. I understand where my confusion came from now !

[malc-c]

Ok I've looked at the PDF (http://www.ee.washington.edu/stores/...ear/mc3340.pdf) for that device, but how does an electronic volume control fit in with my bass extraction / filter thingy ???

PS : 5or 8 £ for a pre-programmed basic PIC ( 675,628,84 ...) ... you're joking, I hope !!!

Whoops - thanks for pointing out the typo... should be £5 like the rest.. now corrected.

And before you ask, that just covers the cost of the PIC and postage to me, then the cost of the post, packing and paypal charges when sending it out again !

[Acetronics2]

[QUOTE=malc-c]Ok I've looked at the PDF (http://www.ee.washington.edu/stores/...ear/mc3340.pdf) for that device, but how does an electronic volume control fit in with my bass extraction / filter thingy ???

I just thought you had understood the presence of D1,D2,Q1,Q2 ... around U1A ...

as for good films : do not make presume the end too early ...

Alain

PS: You buy your PICS from Radiospares ??? ... Who said Cr ...??? Ohhhhh.
RePS: Elektor is the same price ...

[Pic_User]

Hi Malcolm,

A pre-disco name for "disco light" could be "color organ".

I made a color organ in the early 1970's of the last century.

It was great before the word kewl, or way cool, or even cool was used to describe "neat" things.

There seems to be a lot of information on line about color organs. A search may turn up a lot of circuit ideas and schematics.

For instance:
http://www.tinaja.com/glib/muse108.pdf
Describes a color organ as;

Your speaker level input
audio is somehow safety isolated and
then lowpass, bandpass, or highpass
filtered into (usually) three or more
channels. Each channel’s output is
then converted into some dc control
voltage. That dc control voltage then
modulates a "power amplifier" of
some sort. Which in turn relates the
amount of audio energy in the band
to the brightness of one or more
colored lights. For instance, the lows
might be red, the mids green, and the
highs blue. Or whatever"

Now you may be interested, in a single channel "Bass" (lowpass), but the principle should be the same.

PicBASIC should truly turn the simplistic color organ into a true disco light. But be careful to isolate your circuit from the power lines (mains). It is also good practice to isolate the circuit from the input device as well.

This is a fun project and we hope you post where your journey takes you so we can all learn with you.

-Adam-

[Acetronics2]

Hi,

May I point out this little circuit from the far east...

http://www.selectronic.fr/includes_s...ek/HT2040A.pdf

... really ... cool !!!

Alain

[malc-c]

Hi,

May I point out this little circuit from the far east...

http://www.selectronic.fr/includes_s...ek/HT2040A.pdf

... really ... cool !!!

Alain

Thats wicked ! .... nice find

[malc-c]

I made a color organ in the early 1970's of the last century.

God you make me feel old, I think the last century bit made me reach for my zimmerframe and I'm only mid 40's

Thanks for the lead, I'll google colour (or color) organ and see what I get.

No worries on the mains isolation. I use solid state relays that have built in opto isolation. Its a lot safer and easier than messing about with triacs and thryistors like the good old days... I built my first sound to light in '77 consisting of a three way passive crossover, three mains to 6v ac transformers (using the secondry as the primary on the audio) and three 206 thyristors... never really thought about the amp become live at mains potential !!!!

I'll keep you guys posted of any development I get, and hopefully Melanie may let me post the final project and schematic in the respective forums when its completed.