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Topic: imput audio and ouput audio in arduino uno (Read 1 time) previous topic - next topic

apaserv

Hi all, I need help with the following project:
Audio entering in the range of 100 Hz to 7000 Hz.
In Arduino Uno R3, process the audio with high pass filters and low pass.
finally get that audio output processed to enter it in an Amplifier Audio.
If anyone can help me I will be very grateful tested and then publishes the project.
Thanks, Daniel

Grumpy_Mike

You can do some processing with the help of this link:-
http://interface.khm.de/index.php/labor/experimente/arduino-realtime-audio-processing/

But any filtering at 7000Hz is going to be very crude. Remember at 7000Hz your sample rate needs to be at least 14000Hz.

I doubt the results are going to be impressive at all, but without external hardware like an A/D or even D/A and extra memory you can't do much.

DVDdoug

I've never used the Arduino for audio processing and I'm NOT saying this won't work...

BUT, you may run into several limitations....  I wouldn't try it.

If the filters are fixed, I'd suggest an analog filter.    You can make filters with op-amps There's an old book called The Active Filter Cookbook and it may still be in print, or you can find the designs online.  Or, or there are specialized filter chips. 

One advantage of an analog filter is that you don't have to write software.    The analog electronics might be slightly more complicated (compared to plugging an audio shield into the Arduino). 

If you need variable filters the Arduino would make a good controller for a digitally-variable filter (with none of the audio going through the Arduino).

There are also specialized DSP chips, but they are complex and the programming can be complex...    Well...  DSP in the Arduino (or any platform) isn't easy.

joss12

Hello,

I found some good resources on audio processing with Arduino, maybe you should check those out :

Working on Arduino UNO :
http://interface.khm.de/index.php/lab/interfaces-advanced/arduino-realtime-audio-processing/

Working on Arduino DUE :
http://www.electrosmash.com/pedalshield

I personally tried the one with UNO (with audio from PC and audio from guitar) and the result is quite OK to do some basic effects such as reverb, delay and also low order IIR/FIR filters (low-pass, high-pass, ...).

I made a topic to discuss how powerful the DUE would be to implement high order FIR filters :

FIR filter audio processing with DUE

Have a nice day !

mkrumpus

Also take a look at the Audio Hacker Shield, which has a separate ADC and DAC, as well as SRAM for recording audio samples:

http://nootropicdesign.com/audiohacker/


(full disclosure, it's my product)

I designed it after being so inspired by the realtime audio project at

http://interface.khm.de/index.php/lab/interfaces-advanced/arduino-realtime-audio-processing/


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