[PD] jittering sensors

[Sukandar Kartadinata]

On 15.08.2006, at 20:49, patrick wrote:

> hi all,
>
> i've done a project using the MULTIO of mamalala and HID to capture  
> the output of my sensors (infra-red, tilt and such). sadly the  
> values are really jittering

I assume you mean there's (amplitude) noise, rather than timing noise  
which is what jitter usually refers to. Otherwise the previous  
replies regarding drivers/system software apply.

> and i have a logarithm sensor too.
>
> i know that each case is unique

indeed...

> , but maybe there's some rules to stabilize the fluctuation

rule 1: check your circuits first, then your patches

circuit: shielded cables, capacitors across sensor output, better  
power supply, reduced cable length, better signal conditioning (e.g.  
bridge amplifiers),... a scope helps to see where your noise comes from

patches: filtering (averaging is the simplest but often sufficient),  
deglitching (looking for single values outside the general signal  
trend), delta thresholding (only sending values when they change  
significantly),...

Sukandar
www.glui.de