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jahan
Joined: 04 Apr 2005
Posts: 63
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| How to ShiftOut and ShiftIN in CCS? (Like PicBasicPro) |
 Posted: Mon May 23, 2005 8:52 am |
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If I have a 2 wire device with CLK and DAT, can somebody show me a very simple example of sending data out using CCS C?
For example an LCD which only has CLK and DAT lines and I have want to show "Hello".
Thankx |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Mon May 23, 2005 10:56 am |
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| Code: |
#define OUT_CLOCK PIN_B1
#define OUT_DO PIN_B2
void ShiftOut (int8 data)
{
output_low(OUT_CLOCK);
if((data&0x80)==0)
output_low(OUT_DO);
else
output_high(OUT_DO);
data <<= 1;
output_high(OUT_CLOCK);
output_low(OUT_CLOCK);
}
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jahan
Joined: 04 Apr 2005
Posts: 63
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| does ShiftIN works the same way? |
| Posted: Mon May 23, 2005 1:02 pm |
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Thank you for your posting.
It's very clean & clear.
can I ask you if ShiftIN works the same way but backward? and can you post a sample for ShiftIN?
Thankx again. |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Mon May 23, 2005 1:57 pm |
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| Take a look at 74165.c in your examples folder |
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bfemmel
Joined: 18 Jul 2004
Posts: 40
Location: San Carlos, CA.
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| Posted: Mon May 23, 2005 2:21 pm |
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| Quote: | | Take a look at 74165.c in your examples folder |
Actually, 74165.c is in the Drivers folder on my setup with 3.224 so it may be there for you too.
- Bruce |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Mon May 23, 2005 2:46 pm |
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| You are correct. My mistake. |
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rnielsen
Joined: 23 Sep 2003
Posts: 852
Location: Utah
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| Posted: Wed May 25, 2005 1:09 pm |
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Just an FYI...
If you use
| Code: |
.................... if(!(data&0x80))
0028: BTFSC 06.7
002A: BRA 0032
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instead of
| Code: |
.................... if((data&0x80)==0)
0028: MOVF 06,W
002A: ANDLW 80
002C: XORLW 00
002E: BNZ 0036
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you will save two commands in case you are worried about speed. This was compiled for a 18F452.
Ronald |
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Futterama
Joined: 17 Oct 2005
Posts: 98
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| Posted: Tue Oct 18, 2005 7:05 am |
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| Code: | #define OUT_CLOCK PIN_B1
#define OUT_DO PIN_B2
void ShiftOut (int8 data)
{
output_low(OUT_CLOCK);
if((data&0x80)==0)
output_low(OUT_DO);
else
output_high(OUT_DO);
data <<= 1;
output_high(OUT_CLOCK);
output_low(OUT_CLOCK);
} |
How does this code work? I don't see how every bit is clocked out in this code, it doesn't loop as far as I can tell.
And I can't find information regarding this line: "data <<= 1;"
What does that line do?
I can't make it work :-/ |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Tue Oct 18, 2005 7:10 am |
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It should be in a loop
| Code: |
#define OUT_CLOCK PIN_B1
#define OUT_DO PIN_B2
void ShiftOut (int8 data)
{
int8 i;
output_low(OUT_CLOCK);
for (i=0;i<8;i++)
{
if((data&0x80)==0)
output_low(OUT_DO);
else
output_high(OUT_DO);
data <<= 1;
output_high(OUT_CLOCK);
output_low(OUT_CLOCK);
}
} |
| Quote: | And I can't find information regarding this line: "data <<= 1;"
What does that line do? |
same as
And if you don't know what << does, then it is shift left so the statement shifts 1 bit to the left. If you look at the driver files it will show you. |
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Guest
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| Posted: Thu Oct 20, 2005 3:43 pm |
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That code don't work right either.
If i send 0b10100100 I get 0b10100101. |
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Futterama
Joined: 17 Oct 2005
Posts: 98
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| Posted: Thu Oct 20, 2005 5:44 pm |
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Sorry, my browser didn't log me in automatically.
I know what my problem was, I needed shift right, not shift left.
Thanks for you help anyways  |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Thu Oct 20, 2005 6:50 pm |
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| Anonymous wrote: | That code don't work right either.
If i send 0b10100100 I get 0b10100101. |
Get it where? |
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Futterama
Joined: 17 Oct 2005
Posts: 98
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| Posted: Fri Oct 21, 2005 2:49 am |
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| Mark wrote: | | Anonymous wrote: | That code don't work right either.
If i send 0b10100100 I get 0b10100101. |
Get it where? |
Mark, my mistake, thought I got that out of OUT_DO, but I was wrong.
I fixed it to work with my program, and I thank you for your help, no need to dig into it further. |
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