Hi guys, I need a hand with a little project I have been working on. I have a led sequencer that uses some RS flip-flops and uses a 555 timer as a timed trigger. I want to make it sound reactive (switch from timed pulse to sound reactive signal via switch). I have gotten it to “respond” to sound but not very well. The lights are supposed to go R, G, B, over and over (using the 555 as a trigger it does this fine {my circuit works just fine}) but the frequency of the bass just lights up the lights in the r.g.b. pattern way to fast; all you see is steady light!

Can someone help me design a circuit that will trigger my sequencer (falling edge trigger) in away as such that when a bass note is hit, it only triggers once instead of every peak in that note? I am using an amplified condenser mic signal as of right now. My current board runs on 5v and 0v so I would prefer if this board follows suit.

Thanks!

 

Hi Steven,
The project called Dancing LEDs is similar to yours. It uses an electret mic and a preamp. Then it makes a fast attack but slower decay circuit as a pulse stretched to clock a CD4017 10-steps sequencer that drives LEDs or transistors that drive LEDs.

The CD4017 can have its reset pin connected to the 4th output then it counts up to three and starts over again.

The preamp can have a lowpass filter so it responds only to bass sounds if you want.

http://www.electronics-lab.com/proje...021/index.html

Attached Images

DancingLEDs.gif (6.9 KB, 17 views)

__________________
Uncle $crooge

 

The link did not seem to work... I think I will post my schematic thus far so you can see what I have to start with. I was picturing something more like a latched, timed capacitive discharge circuit.

 

Their server is crap. It is working now.
Here is a link to the original project:
http://www.redcircuits.com/Page57.htm

__________________
Uncle $crooge

 

Here is what I am using right now for my sequencer. Your idea seems to require a whole new sequencer. All I need to do is get some sort of circuit that when the mic picks up a sound it pulls the clock low for an adjustable amount of time (in mS) and it stays low regardless of signal until the prescribed amount of time and then goes high until the signal triggers it again.

Attached Images

regist01f.jpg (13.2 KB, 8 views)

 

The trigger input of a 555 can get stuck if the input signal occurs or is still present when it tries to time out.

Just use a lowpass filter so the trigger signal is bass beats. Then you won't need a monostable with an adjustable time.

__________________
Uncle $crooge