Suresh R
Member level 1
cap sense key
Hi all,
I am using capacitor sensing technique for sensing user key press.
NE556 was connected in Astable mode and the capsense act as a capacitor in that. Hence the change in output frequency is monitored by a controller for detecting user key press.
But with this method, i couldnt get a consistant result!
i.e., for each key the frequency during key press varies.
also, if i place a 2mm thick glass sheet over capsense, i couldnt get a better frequency variation..
Hence it would be great if i could get some ideas on how it could be achieved.
i am also interested in a method where i could make the port logic level high/low for before/during touch. I am yet to get a method to achieve this. can i get a hint on how it need to be approached?
Suresh.
Hi all,
I am using capacitor sensing technique for sensing user key press.
NE556 was connected in Astable mode and the capsense act as a capacitor in that. Hence the change in output frequency is monitored by a controller for detecting user key press.
But with this method, i couldnt get a consistant result!
i.e., for each key the frequency during key press varies.
also, if i place a 2mm thick glass sheet over capsense, i couldnt get a better frequency variation..
Hence it would be great if i could get some ideas on how it could be achieved.
i am also interested in a method where i could make the port logic level high/low for before/during touch. I am yet to get a method to achieve this. can i get a hint on how it need to be approached?
Suresh.