We are developing a keyboard for electric ovens, using the MC9S08PT60 TSI.
We took a look at the app note AN3863 and saw some grounding and shielding tecniques.
And we are wondering what are the best tecniques for this kind of application:
1) No grounding or shielding over electrodes area
2) Only shield nearby electrodes
3) Only hatch ground plane on the bottom
Could anybody give us some advice, tips, etc?
Note: It is an ordinary 12-key keyboard with acrylic overlay. All the system is integrated in one 2-layer board.