Howdy,
I am trying to make a audio spectrum analyzer. My plan is to take the audio to a MSGEQ7 seven band graphic equalizer, controlled with a 555 timer, then take the output of the MSGEQ7 to a demux. From there go to 7 LM3916 LED display drivers. The issue I am facing is finding a demux that is just controlled by the timer. The output of the equalizer is separated such that each of the pulses represents a specific frequency. So the first puls will be 63Hz, followed by 160Hz, etc. So what I need is for the demux is to do the opposite of what is going on in the equalizer. So the output of 1 would be high for one pulse, then low for the next 7, while pin 2 would be high on the second pulse etc. Is there a chip for this?
Thank you

 

Please show your circuit or block diagram.

 

Please show your circuit or block diagram.

Certainly.

 

Quote (datasheet)

• Only an off chip resistor and capacitor are needed to select the on chip clock oscillator frequency.
  The filter center frequencies track this frequency.
• The seven frequencies are peak detected and multiplexed to the output to provide a DC representation of the amplitude of each band.
• Gain AV Peak input to DC output, Vin = 100 mVpp, fin = 1 kHz Min:Typ:Max 20:22:24 (dB)

((as i get it)) it outputs analog value of the signal e.g. you need 7 sample and hold (and perhaps regenerate A/D hold D/A out) buffers ((i may get it incorrect - donno the chip))
something
https://www.maximintegrated.com/en/...ters/analog-to-digital-converters/DS1843.html
http://www.linear.com/solutions/1196
...
your pin7 on MSGEQ7 is floating . . .

 

Howdy,
I am trying to make a audio spectrum analyzer. My plan is to take the audio to a MSGEQ7 seven band graphic equalizer, controlled with a 555 timer, then take the output of the MSGEQ7 to a demux. From there go to 7 LM3916 LED display drivers. The issue I am facing is finding a demux that is just controlled by the timer. The output of the equalizer is separated such that each of the pulses represents a specific frequency. So the first puls will be 63Hz, followed by 160Hz, etc. So what I need is for the demux is to do the opposite of what is going on in the equalizer. So the output of 1 would be high for one pulse, then low for the next 7, while pin 2 would be high on the second pulse etc. Is there a chip for this?
Thank you

It would be something like this. My concern (with the schematic posted below) is that the MSG07 reset pin is not held high long enough - you may need a 555 as a single shot to use Q3 of 4-bit counter to trigger the 555 monostable (with an non to invert the 555 signal). Then use that 555 monostable output to keep the MSQ07 AND the 4-bit counter in reset together.

The outputs 0-6 of the cd4051 go to your seven LM3916.

Good luck.