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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Mon, 5 Jan 1998 06:59:58 GMT
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Original-From:
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Brian Schmalz <brian.schmalz@corp.honeywell.STOPSPAMMERScom>
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Viewed:
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1338 times
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At 4:27 PM -0600 12/31/97, Tom Brusehaver wrote:
> Message sent by Tom Brusehaver <tomb@augusta.netperceptions.com>
> to the mot-68hc11-apps Mailing List.
>
> > > > > > "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.. :)
> 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.
Here is an Interactive C file to do just that. Seems to work well in the
10 minues of testing I've just done. :) Let me know if anyone has problems
with this:
*Brian Schmalz
/* Function to enable SPI port as digital I/O */
/* First you must DisableSPI(), then you can */
/* WritePortD(). If you need to use SPI again, */
/* use EnableSPI(). To read from port D, use */
/* ReadPortD(). */
#define D_ALL_OUT 0b00111100
#define D_ALL_IN 0b00000000
/* Set bits in dir to set direction of I/O on port D */
/* A 1 in bits 5 through 2 will enable that bit in */
/* port D as output. Others will be inputs. Does not */
/* affect bits 0 and 1 (TxD and RxD) */
/* Use
DisableSPI(D_ALL_OUT); or
DisableSPI(D_ALL_IN); or your own variation. */
/* Pins on SPI port for Handy Board map to bits in */
/* WritePortD() like this: (looking at HB with LCD at top */
V G
2 5
3 4
X X
So to turn on the pins on the right and turn off pins on the */
/* left, use WritePortD(0x00110000); */
void DisableSPI(int dir) {
int x;
bit_clear(0x1028, 0b01000000);
x = peek(0x1009);
x = (x & 0b00000011) | (dir & 0b00111100);
poke(0x1009, x);
}
void EnableSPI(void) {
int x;
x = peek(0x1009);
x = (x & 0b00000011);
poke(0x1009, x);
}
void WritePortD(int val) {
int x;
x = peek(0x1008);
x = (x & 0b00000011) | (val & 0b00111100);
poke(0x1008, x);
}
int ReadPortD(void) {
return(peek(0x1008) & 0b00111100);
}
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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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