Cypress CapSense CY8C20x36 Guide de l'utilisateur Page 45

  • Télécharger
  • Ajouter à mon manuel
  • Imprimer
  • Page
    / 75
  • Table des matières
  • MARQUE LIVRES
  • Noté. / 5. Basé sur avis des utilisateurs
Vue de la page 44
Getting Started with CapSense
®
Document No. 001-64846 Rev. *I 45
Figure 3-19. Median Filter (16-sample) Finger Touch
For more information about how to implement a median filter, see the code example CSA Software Filters with
EzI2Cs Slave on CY8C20xx6.
3.4.4 Jitter Filter
3.4.4.1 Jitter Filter for Noisy Slider Data
The centroid function is used to estimate finger position on a slider. When the signal level is low, usually because of
thick overlay on the slider, the estimate of finger position will appear to shake and jitter even when the finger is held at
a fixed position. This jitter noise can be removed using a jitter filter. To do this, the previous input is stored in a buffer.
The current input is compared to the previous output. If the difference is greater than ±1, the output is changed by ±1
(matching sign), as shown in Equation 22. This is a nonlinear filter.
 
 
  Equation 22
 
 
 
 

Figure 3-20 shows the results of applying a jitter filter applied to noisy centroid data.
Vue de la page 44
1 2 ... 40 41 42 43 44 45 46 47 48 49 50 ... 74 75

Commentaires sur ces manuels

Pas de commentaire