Cycling 74 » Topic: Issues with controlling sound using a potentiometer, suggestions PLEASE!

Issues with controlling sound using a potentiometer, suggestions PLEASE!

HenrySwadesir — Thu, 23 Aug 2012 08:50:04 +0000

Im very very new to MAX so please excuse my lack of knowledge and terminology. Im currently working on a project which uses the input data from an Arduino board using different sensors to communicate with MAX via Maxuino. I have managed to patch my Potentiometer to a basic LFO in MAX using MAXUINO. I intend on eventually using other sensors but i have one hurdle to get over first.

here lies my problem, the 'analog' data from my Potentiometer gives me a range from [ 0.00 to 1 ], i can only make noise by multiply my LFO by *1000 (< like that). So, when i twist the knob on the potentiometer, at 0.00 there is no sound and then suddenly sound when it reaches the other side and goes from 0.99 to 1 there is sound. I want to make my sound increase or decrease as the Potentiometer is twisted.

Im really stuck and im a total noob when it comes to MAX, I'm just looking for any advice or suggestions that could help me with my project.

ive included a screen shot of my set up and a sketch of how the connection between the potentiometer and MAX works or how i think it should work…

thankyou

[attachment=201994,4326] [attachment=201994,4327]

Re: Issues with controlling sound using a potentiometer, suggestions PLEASE!

Richard Garrett — Thu, 23 Aug 2012 10:22:31 +0000

Hello,

I think I’ve spotted your problem.

The box that multiplies the input value reads [* 1000] – This is integer multiplication, therefore any value between 0.00 and 0.99999… will return 0; a value >=1 and <2 will give 1 and so on.

If you change the multiplication to [* 1000.] – note the decimal point- you will get floating-point multiplication and, I think, the values you’re looking for.

everybody does this from time to time :)

best

richard

Re: Issues with controlling sound using a potentiometer, suggestions PLEASE!

n00b_meister — Thu, 23 Aug 2012 15:53:54 +0000

And in addition to Richard’s clear advice, ensure that the pot you’re using is linear: rotate the pot to approx. halfway; it should read approx. 0.5 in the Maxuino segment, if it reads significantly less than 0.5 then it may well be a logarithmic pot, where the resistivity is not linear, but exhibits a ‘jump’ at the upper limit. Or use a multimeter.

And look at the [split] object if you want to create some arc sectors.

Brendan

Re: Issues with controlling sound using a potentiometer, suggestions PLEASE!

Steven Miller — Fri, 24 Aug 2012 03:27:51 +0000

In reply to Brendan’s post: Except that, to get linear behavior of frequency or amplitude controls you’ll actually want to use a pot with logarithmic taper (or convert linear to log inside MAX). Both pitch and loudness perception mechanisms in humans are ratiometric or logarithmic.