Re: Trouble with 4x4 Telephone Keypad

On 18 Apr 2005 11:05:47 -0700, "Jack// ani" <nospam4u_jack@xxxxxxxxx>
wrote:

>Lord thanks a lot for reply. I'm very sorry I didn't stated the problem
>clearly. Pullup resistors (20K -10K) are internal to the chip and are
>*not* on my keypad. Please refer to page 5 of the data***. Keypad is
>just a simple arrangement of switches in 4x4 matrix, which is shorting
>the corresponding row and column. Problem here is after pressing the
>switch I've to connect the shorted terminal to ground, in order to
>generate a tone. I want to get the tones only by pressing switches
>itself. I know there are many chips around which can easily solve my
>problem, but I'm interested to do with this one.

---
Unfortunately, with the array of 16 SPST tactile switches you propose
to use, there's no way you're going to get what you want.

--
John Fields
Professional Circuit Designer
.

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