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Christophe
Joined: 10 May 2005 Posts: 323 Location: Belgium
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implementing diode keyboard matrix |
Posted: Tue May 10, 2005 1:27 am |
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Hi,
I want to implement a 9 x 8 keyboard matrix (72 keys) with some diodes for simultaneous keypress detection. So I will have rows and columns. How does the algorithm works? Are the Rows outputs and the columns inputs? Are there any examples?
http://www.sensotec.be/ASP/Catalog.asp?ID=Sensotec%20EUROSCOPE&LC=10 You can see the device with the buttons.. |
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newguy
Joined: 24 Jun 2004 Posts: 1903
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Christophe
Joined: 10 May 2005 Posts: 323 Location: Belgium
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Posted: Thu May 12, 2005 1:51 am |
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He's using portB interrupts.. I cannot use that code because I have 9 rows x 8 columns |
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newguy
Joined: 24 Jun 2004 Posts: 1903
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Posted: Thu May 12, 2005 8:30 am |
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Right. I didn't say that you could use that code as is, only that it would help give you ideas about what to do. Now that you see how it's done with 16 buttons, couldn't you "scale" that approach to get your 72 buttons? |
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treitmey
Joined: 23 Jan 2004 Posts: 1094 Location: Appleton,WI USA
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Posted: Thu May 12, 2005 8:47 am |
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..
Last edited by treitmey on Thu May 12, 2005 10:03 am; edited 3 times in total |
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Christophe
Joined: 10 May 2005 Posts: 323 Location: Belgium
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Posted: Thu May 12, 2005 8:51 am |
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Well the matrix can be divided into 3 matrices:
* 3R x 8C matrix : simultaneous press detection needed
* 1 x 8 matrix : simultaneous
* 5 x 8 matrix: only single press detection needed |
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treitmey
Joined: 23 Jan 2004 Posts: 1094 Location: Appleton,WI USA
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Posted: Thu May 12, 2005 9:00 am |
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..
Last edited by treitmey on Thu May 12, 2005 10:04 am; edited 1 time in total |
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Christophe
Joined: 10 May 2005 Posts: 323 Location: Belgium
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Posted: Thu May 12, 2005 9:20 am |
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Of course that is possible..
set row '1'
read 8 column bits
=> decode bits to keypresses |
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treitmey
Joined: 23 Jan 2004 Posts: 1094 Location: Appleton,WI USA
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Posted: Thu May 12, 2005 10:00 am |
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Sory, I guess you have this solved. |
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Guest
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Posted: Mon May 16, 2005 1:48 pm |
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I mean it is possible without extra IC's ... with a pic only and diodes.. I'm just asking for some tips/code samples , algorithms, something that can get me started... |
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