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Topic: How to correctly interface Audio In and Out (line out or headphone) with Arduino (Read 3623 times) previous topic - next topic

DaAwesomeP

Ok, so I re-wired up the circuit and the Arduino gave a reading of 509 and 510. I tested the circuit with the multimeter and it now gives off 2.5v DC. Thank you!

I tried the DTMF library to no avail. The Goertzel algorithm library, when set to 697hz lit up the LED when almost any number was pressed. At least now I'm getting a reading. Should I start a new forum page for helping me with the library?

To understand the touch-tone system (it is almost like an LED matrix), look at the table here: https://en.wikipedia.org/wiki/Dual-tone_multi-frequency_signaling#Keypad
An Arduino is not a toy; it's a professional utilitarian tool.

Grumpy_Mike

Glad it is working.
However the Goertzel algorithm is only good for one specific tone, here you want to detect up to eight. If it fires with any key then perhaps the threshold is set too low.
There are special chips you can get to decode DTFM I think you might be better off using one of them. or use a full FFT.

DaAwesomeP

Thanks for all your work! I know I had a lot of problems.

Once last thing: Do you know of any FFTs that would be good for this project?
I found this one: http://wiki.openmusiclabs.com/wiki/ArduinoFFT
An Arduino is not a toy; it's a professional utilitarian tool.

Grumpy_Mike

Quote
Do you know of any FFTs that would be good for this project?

Sorry, while I have used FFTs on other machines I haven't used the ones on the Arduino.

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