Hi,
I am currently working on a audio mixing console and part of it consists of a graphic equalizer, I will be prototyping this entire project on breadboards first. I am thinking I will need two graphic EQ's, one for each channel of output.
My idea originally was 3 band pass filters each to have a resonant frequency in the range of the Low, Mid and High, then passing through a diode and then into an ADC and then into a driver and then into the LED's on the display.
(Image 3 shows the functional blocks)
Today I have learnt that using a band pass filter is an ineffective method as the Q factor is too small and the bandwidth is too great. I have looked around and it seems an active band pass filter is the way to go based on an op amp. After the active band pass filter, I am thinking feed this through a diode to take out the negative component this would make it suitable for the ADC. (Image 2 shows a quick circuit diagram of the active filter)
However I am unsure about what the best option would be regarding the construction of the ADC. Considering I will need 3 ADC's for each bar.
1) A successive approximation counter, I have some designs it uses op amps and counters for the graphic equalizer. I think this would be difficult to construct considering my resources it would also accumulate 2 to 3 breadboards.
2) A Pic Microcontroller, after looking around on the net it seems that it can be done, it seems a much more viable option as I would only need 1 PIC for each bar. If so I will probably need to take samples at 10 to 20 hz. I am a also unsure about the output I know it will be binary format, It wont be able to go directly into the LED's. Maybe I need a logic system between this to determine the height of the bar depending on the magnitude of the binary output?
(Image 1 shows the LED Bar display)
Any help or guidance would be greatly appreciated, I am a bit uncertain of the feasibility of this project. Thank you for reading
I am currently working on a audio mixing console and part of it consists of a graphic equalizer, I will be prototyping this entire project on breadboards first. I am thinking I will need two graphic EQ's, one for each channel of output.
My idea originally was 3 band pass filters each to have a resonant frequency in the range of the Low, Mid and High, then passing through a diode and then into an ADC and then into a driver and then into the LED's on the display.
(Image 3 shows the functional blocks)
Today I have learnt that using a band pass filter is an ineffective method as the Q factor is too small and the bandwidth is too great. I have looked around and it seems an active band pass filter is the way to go based on an op amp. After the active band pass filter, I am thinking feed this through a diode to take out the negative component this would make it suitable for the ADC. (Image 2 shows a quick circuit diagram of the active filter)
However I am unsure about what the best option would be regarding the construction of the ADC. Considering I will need 3 ADC's for each bar.
1) A successive approximation counter, I have some designs it uses op amps and counters for the graphic equalizer. I think this would be difficult to construct considering my resources it would also accumulate 2 to 3 breadboards.
2) A Pic Microcontroller, after looking around on the net it seems that it can be done, it seems a much more viable option as I would only need 1 PIC for each bar. If so I will probably need to take samples at 10 to 20 hz. I am a also unsure about the output I know it will be binary format, It wont be able to go directly into the LED's. Maybe I need a logic system between this to determine the height of the bar depending on the magnitude of the binary output?
(Image 1 shows the LED Bar display)
Any help or guidance would be greatly appreciated, I am a bit uncertain of the feasibility of this project. Thank you for reading
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