PICAXE frequencies needed for SOUND

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Wannabe Geek

#21919 11-May-2008 00:27

HIYA
We need the frequencies for the notes from middle c throgh to c1 ie C D E F G A B C D inorder to complete a Science project. Anyone know them or wher to get them A google search has not helped thus far
Thanks

paradoxsm

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#129980 11-May-2008 01:42

Is it a picaxe 08 or a picaxe 08-M version? (or something elese)

picaxe -M can support a proper "play"command whereas the original could only generate tones. (you can sweep them using step commands, generate PWM noises and a pseudo white noise by increasing the variable beyond "limits", use lookup tables and the like but this is getting a bit advanced) I made a funky little beat machine once using 3 sound generators off the axe as tone, PWM, noise and filtered it using analog stuff switched by a further ouput..

Middle "C" (C4) is about 262 Hz, C1 is about 32 Hz C2 is about 66Hz , C3 is about 130Hz

I cheated and just went log Octal, 32, 64, 128, 256, 512 etc, the notes were a little "flat" but nobody really cared if the notes from some squarking device were slightly off key.

manhinli

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#129994 11-May-2008 10:04

There is also a thing called Tune Generator (or something like that), and also a command called tune.

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Scoutleader

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Wannabe Geek

#130003 11-May-2008 11:19

Thanks guys,
it is a PICAXE 28.

I developed and built a light following buggy which used the picaex 08, as a programming exercise for my students.

We had a play with the sound command. I had a list of frequencies and their associated notes.
The students were given the task of firstly getting the chip to play the national anthem and then to come up with a tune of thier own.
Needless to say there were the expected Smoke on the water attempts SMILES..

However I have since misplaced my list.

The list was generated by running a for next loop to play a slowly increaing tone. We debugged the variable. The notes was played into a piano tuner. When a "pure" note was reached we noted down the frequency from the debug table.
Thius a list of quite accurate frequencies and thier associated notes was generated.

I used a students' piano tuner for this, else I woudl just repeat the exercise again myself.

I am now developing a project with my son, using the picaxe 28, for his science fair, and need the notes played to be as accurate as possible.