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How to build a 8x8 keypad?

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Zedman

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Anyone can suggest a cheap solution how to build a
8x8 keypad? It can be touchpad or similar but it should
be roboust and reliable.
It would be a part of an electronic memory game for
the kids.

any ideas?

thanks in advance,
Zed
 

artem

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8x8 keypad

If it is gaming you should use high speed scan rate for keypad .
You can try to experimen with cmos IC to implement touchpad alike sensor .
 

hqqh

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keyboard 8x8

hi,

have a look at https://www.qprox.com/products/index.php. they have ic's for developing touch sensitive keyboards. the ic's have a digital output so that you can interface it with a small microcontroller. i will try to build my own development-board in the during the next week. then i can provide my expiriences with these ic's. as i know the max. pad count is 48. but i think you can use two or three ic's to get a higher number of keys.
most of these chips are avalible at digikey.com.

greetings,
hqqh
 

    Zedman

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Zedman

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8x8 keyboard

Thanks,

This IC can be a solution to me, what kind of surface
or sensor should be used with it? Simple PCB traces
will do?

thanks,
Zed

Added after 12 minutes:

I got in it the datasheet, shaped PCB traces will be
the sensors. QT60645 can do 64 keys.
How does it cost?
Unfortunatelly I can't buy it here in Hungary, I did
not find any distributors here. :(

Zed
 

hqqh

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8x8 keypad circuit

hi,
i found QT60645 at www.digikey.com (14$). i dont know whether they deliver packets to hungary. just try it.
greetings,
hqqh
 

Zedman

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keypad 8x8 datasheet

Thanks,

anyway I'd like to see your results with it here,
or in private message.

thanks again
Zed.
 

gidimiz

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8x8 keypad scan chip datasheet

Hi,

I think that the best way is to use those tuch buttons that use metal surface. This dont have any movinf parts, so you can do what ever you want to do.
Here are some ideas:
The pdf is a part of a circuit to drive 120V, you dont need that so i left only the touch button.
The jpg is a circuit that i used for something else. i did find out that when i was touching the touch wire, the NAND gate was latching. So you can use that circuit also...

Good luck.
 

Zedman

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keyboard scan 8x8

Thanks gidimiz,

but since I need 64 buttons the IC solution seems
simplier (but probably costs more).

thanks,
Zed
 

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