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Grogster

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Joined: 31/12/2012
Location: New Zealand
Posts: 9590

Posted: 06:28pm 24 Jul 2016

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KEYPAD command is very useful, and I would be one person voting to keep it. While it's true that perhaps not that many people use it, for those that do - especially people new to keypads and the whole matrix-scanning idea, the simplicity of the built-in KEYPAD command makes life so much easier for them.

Having said that, depending on how much space it uses up in MMBASIC, it could be something that could be sacrificed, and perhaps replaced with a CSub stored in the library(or main code), and called with an interrupt, that would do the same thing. Weather that would save anything on the memory already used for the KEYPAD command, I don't know, but I don't expect that KEYPAD takes up much memory to implement.

An advantage of the CSub approach, would be that the C gurus could include the de-bounce that MicroBlocks wants.....

@ MicroBlocks - a similar idea to the ASCII keyboard we were playing with a while back. You finished a code for that idea using a simple 14 or 16 pin DIL chip didn't you? I seem to recall you did, but I digress......

Smoke makes things work. When the smoke gets out, it stops!

Lou

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Joined: 01/02/2014
Location: United States
Posts: 229

Posted: 06:39pm 24 Jul 2016

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Geoff,
I use the keypad and LCD commands with many of my projects, please don't send either of them to the uMite dust bin.

Jean,
I use the keypad shown on your last post along with a 16x2 blue backlit LCD module on my LCDuMite projects (the boards are available from MicroMite.org). If you have room for the keypad on your project you get 16 keys with no software to write using only 8 port lines. Pretty slick.
It all fits nicely in a box like this one.

Lou

Microcontrollers - the other white meat

robert.rozee
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Joined: 31/12/2012
Location: New Zealand
Posts: 2431

Posted: 07:33pm 24 Jul 2016

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an industrious soul could write a charlieplex driver as a custom function, that would give you:

12 keys using 4 i/o lines
20 keys using 5 i/o lines
30 keys using 6 i/o lines
42 keys using 7 i/o lines
56 keys using 8 i/o lines

see:
https://en.wikipedia.org/wiki/Charlieplexing#Input_data_multiplexing

note: the diodes may be omitted if you do not require n-key rollover simply by enforcing in software the rule, "all keys must return to the 'up' state between keypresses".

cheers,
rob :-)Edited by robert.rozee 2016-07-26

KRZ3
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Joined: 31/12/2014
Location: United States
Posts: 38

Posted: 02:13am 25 Jul 2016

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I too would vote to keep the keypad command. I would actually love the ability to extend it to allow for a 4x5 matrix. I agree that C-functions would be great here. I wish someone could come up with a solution for a 4x5 or larger keypad command. I have a product that uses the keypad function, but due to the limited reading I have to double tap the function of certain keys to get around the limited 4x4 matrix.

MicroBlocks

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Joined: 12/05/2012
Location: Thailand
Posts: 2209

Posted: 10:38am 25 Jul 2016

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KRZ3
I am working on a 4x4 matrix and i think i can squeeze in two pins to make a larger matrix.
Which would be better a 4x6 or a 5x5 matrix?

Microblocks. Build with logic.

Chris Roper
Senior Member

Joined: 19/05/2015
Location: South Africa
Posts: 280

Posted: 10:52am 25 Jul 2016

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Depends if you need 24 or 25 keys.

If you have the extra pins it may be best to do a 4x5 matrix with a shift key giving a total of 40 functions on 10 pins.

That would make a nice calculator keypad.

Cheers
Chris

Edited by Chris Roper 2016-07-26

http://caroper.blogspot.com/

PicFan
Senior Member

Joined: 18/03/2014
Location: Austria
Posts: 133

Posted: 12:34am 26 Jul 2016

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Geoffg said I did look at extending the KEYPAD command and eventually discarded it. It turned out to not be that simple to implement and, as far as I could see, not many people would have been interested in using the extended feature anyway. In fact, I don't think many people use the KEYPAD command at all and it is on my list for possible removal.

Geoff

Hello Geoff !

The KEYPAD-Command is very important, please do not remove !!

Thank you very much !!

Wolfgang

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