Subject:
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Re: Digital outputs.
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Wed, 31 Dec 1997 22:27:47 GMT
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Original-From:
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Tom Brusehaver <tomb@augusta.#AvoidSpam#netperceptions.com>
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Viewed:
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1344 times
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> > > > > "G" == =?iso-8859-1?Q?Germ=E1n Gentile?= <iso-8859-1> writes:
G> Wich are the options to have 3 digital outputs in the handyboard?
G> No matter if i have to do little modifications to the Hardware. I
G> already know how to conect the keypad if you can tell me how
G> obtain 3 outputs.. :)
Handyboards are tough. I love 'em, but they don't have outputs.
Anyway, There are 4 outputs for each motor controller. If you don't
need both, pull one, and replace it with a 16pin header. (if you look
on the HB web page, the sonar connector uses 2 of them).
Another option is some memory decoding. The 74138(9?) outputs are on
the expander board pins. Setting up 3 memory addresses (or ranges)
will allow you have outputs.
The SPI port is sitting there. I think you can get at 3 outputs from
those pins (SD/RD/CLK).
You'll have to do peeks and pokes to access these bits. Even setting
the data direction registers to get outputs.
-------------------------------------------
This is a waay off left field idea.
Instead of setting outputs, connect the columns to 5V through a
resistor, a different value for each column. Connect the columns to
the E port, and measure the analog value returned. If someone pressed
more than one key you code could be confused a bit. It would work.
Another idea along these lines would be dasy chaining the rows through
resistors, then you would only have one E port used.
+++
555
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>>>
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Eport-123-VVV-+
+-455-VVV-+
+-789-VVV-+
gnd--*0#-VVV-+
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Message has 1 Reply:
 | | Re: Digital outputs.
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| On Wed, 31 Dec 1997, Tom Brusehaver wrote: <snip> (...) </snip> yet ANOTHER idea, if you are suitably masochistic, is to use the SPI port for a much more extensible I/O system. As you know, SPI uses 4 basic control signals, MOSI, MISO, CLK and SS... (...) (27 years ago, 1-Jan-98, to lugnet.robotics.handyboard)
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Message is in Reply To:
| | Digital outputs.
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| Wich are the options to have 3 digital outputs in the handyboard? No matter if i have to do little modifications to the Hardware. I already know how to conect the keypad if you can tell me how obtain 3 outputs.. :) (27 years ago, 31-Dec-97, to lugnet.robotics.handyboard)
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