soundwheel - controlling audio pitch with a speedometer

Thread Starter

TillFly

Joined Oct 26, 2016
68
Hello together,

I want to build a "soundwheel", which is a bicycle equipped with a microphone and a speaker and the recorded sound shall be manipulated in relation to the current speed of the wheel.

Here´s my current idea of the signal chain for the first analog prototyp:

1. with sensor and magnet of a speedometer I should get a kind of PWM signal.
2. then converting the frequency to a steady voltage for integrating it into the circuit for sound manipulation. I´ve already seen some freq-to-voltage-converter circuits which should do its job.
3. Now I need a logic to control the pitch of this thing(http://www.velleman.eu/products/view/?country=be&lang=en&id=362322) with the steady voltage
the pitch module can pitch audio in 7 steps with two buttons, a "pitch up- " and "pitch down-button".
Now my main question: How can I control the "stepped" pitch with the steady voltage? What components/circuits would I need for that?
maybe a "voltage change detector" for certain treshholds. the treshholds would then enable trigger which push either "pitch up" or "pitch down". could tha twork? how to do?

In Max MSP I´would do it like this:
- e.g.: steady voltage would be 5V. I would scale the 5V to the 7 steps.
- then I would use change objects. one triggers if steps increase the other when steps decrease

Besides my analog technical question.
What do you think in general about the circuit idea?
Where do you see special potentials challenges for e.g. good stable sensor data...
I know pitch shifting in analog is rather bad but nevertheless I would like to try a complete analog version.

I´m very excited about your answers,
Best,
Dirk
 

Thread Starter

TillFly

Joined Oct 26, 2016
68
So far I just see a solution with seven schmitt triggers and a routing component, which passes the logic 1 in turns left and right to "pitch down" and "pitch up"... . are there routing components which switch automatically betwenn 2 channels?
Please comment on this thoughts.
I´m an analog newbie...
 
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