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treitmey
Joined: 23 Jan 2004
Posts: 1094
Location: Appleton,WI USA
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| problem with pointers |
 Posted: Thu Nov 11, 2004 11:03 am |
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I have a problem with this code. Can someone see the error?
ccs ver 3.212 and a 16f877 @ 16MhZ
When I step through it, the watch window is correct. But on the rs232 debug window, I don't get 70,80,90 as I expect.
| Code: | #include <16F877.h>
#device *=16
#include <string.h> //for memcmp
#case
#use delay(clock=16000000)
#fuses HS,NOWDT,NOPROTECT,NOLVP
#ZERO_RAM
#define VER_MAJOR 1
#define VER_MINOR 00
#use rs232(baud=57600,xmit=PIN_A2,INVERT,stream=DEBUG)
struct pkt
{
BYTE type;
BYTE data[25];
};
struct pkt Pkt0,Pkt1,Pkt2,Pkt3;
struct pkt *p_pkt[4];
#define TXSIZE 32
#define TXMASK TXSIZE-1
int8 TX_BUF[TXSIZE];
int8 tx_indx_i,tx_indx_o;
#define RXSIZE 16
#define RXMASK RXSIZE-1
int8 RX_BUF[RXSIZE];
int8 rx_indx_i=0,rx_indx_o=0;
//======================= MAIN ============================//
void main(void)
{
setup_adc_ports(NO_ANALOGS);
set_tris_a(0xFF);
set_tris_b(0xFF);
set_tris_c(0xFF);
set_tris_d(0xFF);
set_tris_e(0xFF);
p_pkt[0]=&Pkt0;
p_pkt[1]=&Pkt1;
p_pkt[2]=&Pkt2;
p_pkt[3]=&Pkt3;
//--------- START -------//
fprintf(DEBUG,"STARTING U11\n\r");
fprintf(DEBUG,"FIRMWARE VERSION %u.%02u\n\r",VER_MAJOR,VER_MINOR);
Pkt0.type = 0x10;
Pkt0.data[0]=0x20;
Pkt0.data[1]=0x30;
Pkt1.type = 0x70;
Pkt1.data[0]=0x80;
Pkt1.data[1]=0x90;
fprintf(DEBUG,"%X %X %X\n\r",Pkt0.type,Pkt0.data[0],Pkt0.data[1]);
fprintf(DEBUG,"%X %X %X\n\r",Pkt1.type,Pkt1.data[0],Pkt1.data[1]);
fprintf(DEBUG,"----------\n\r");
fprintf(DEBUG,"%X \n\r",p_pkt[0]->type);
fprintf(DEBUG,"%X \n\r",p_pkt[0]->data[0]);
fprintf(DEBUG,"%X \n\r",p_pkt[0]->data[1]);
fprintf(DEBUG,"----------\n\r");
fprintf(DEBUG,"%X \n\r",p_pkt[1]->type);
fprintf(DEBUG,"%X \n\r",p_pkt[1]->data[0]);
fprintf(DEBUG,"%X \n\r",p_pkt[1]->data[1]);
while(1){}
}
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Thu Nov 11, 2004 1:11 pm |
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| Code: | #include <16F877.h>
#device *=16
#include <string.h> //for memcmp
#case
#use delay(clock=16000000)
#fuses HS,NOWDT,NOPROTECT,NOLVP
#ZERO_RAM
#define VER_MAJOR 1
#define VER_MINOR 00
#use rs232(baud=57600,xmit=PIN_A2, INVERT, stream=DEBUG)
struct pkt
{
BYTE type;
BYTE data[25];
};
struct pkt Pkt0,Pkt1,Pkt2,Pkt3;
struct pkt* p_pkt[4];
#define TXSIZE 32
#define TXMASK TXSIZE-1
int8 TX_BUF[TXSIZE];
int8 tx_indx_i,tx_indx_o;
#define RXSIZE 16
#define RXMASK RXSIZE-1
int8 RX_BUF[RXSIZE];
int8 rx_indx_i=0,rx_indx_o=0;
//======================= MAIN ============================//
void main(void)
{
setup_adc_ports(NO_ANALOGS);
set_tris_a(0xFF);
set_tris_b(0xFF);
set_tris_c(0xFF);
set_tris_d(0xFF);
set_tris_e(0xFF);
p_pkt[0]=&Pkt0;
p_pkt[1]=&Pkt1;
p_pkt[2]=&Pkt2;
p_pkt[3]=&Pkt3;
//--------- START -------//
fprintf(DEBUG,"STARTING U11\n\r");
fprintf(DEBUG,"FIRMWARE VERSION %u.%02u\n\r",VER_MAJOR,VER_MINOR);
Pkt0.type = 0x10;
Pkt0.data[0]=0x20;
Pkt0.data[1]=0x30;
Pkt1.type = 0x70;
Pkt1.data[0]=0x80;
Pkt1.data[1]=0x90;
fprintf(DEBUG,"%X %X %X\n\r",Pkt0.type,Pkt0.data[0],Pkt0.data[1]);
fprintf(DEBUG,"%X %X %X\n\r",Pkt1.type,Pkt1.data[0],Pkt1.data[1]);
fprintf(DEBUG,"----------\n\r");
fprintf(DEBUG,"%X \n\r",(p_pkt[0])->type);
fprintf(DEBUG,"%X \n\r",(p_pkt[0])->data[0]);
fprintf(DEBUG,"%X \n\r",(p_pkt[0])->data[1]);
fprintf(DEBUG,"----------\n\r");
fprintf(DEBUG,"%X \n\r",(p_pkt[1])->type);
fprintf(DEBUG,"%X \n\r",(p_pkt[1])->data[0]);
fprintf(DEBUG,"%X \n\r",(p_pkt[1])->data[1]);
while(1){}
}
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treitmey
Joined: 23 Jan 2004
Posts: 1094
Location: Appleton,WI USA
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| Posted: Thu Nov 11, 2004 1:30 pm |
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THANKS, THANKS,THANKS, THANKS,THANKS, THANKS!
order of evaluation, I get it...
never saw that comming.
: )
Last edited by treitmey on Wed Jan 11, 2006 10:14 am; edited 1 time in total |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Thu Nov 11, 2004 2:37 pm |
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| Welcome, welcome, welcome. |
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treitmey
Joined: 23 Jan 2004
Posts: 1094
Location: Appleton,WI USA
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| Posted: Thu Nov 11, 2004 3:59 pm |
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Perhaps someone can help me on this also. Why won't this work. : (
| Code: | #include <16F877.h>
#device *=16
#include <string.h> //for memcmp
#case
#use delay(clock=16000000)
#fuses HS,NOWDT,NOPROTECT,NOLVP
#ZERO_RAM
#define VER_MAJOR 1
#define VER_MINOR 00
#use rs232(baud=57600,xmit=PIN_A2,INVERT,stream=DEBUG)
struct pkt
{
BYTE type;
BYTE data[25];
};
struct pkt Pkt0,Pkt1,Pkt2,Pkt3;
struct pkt * p_pkt[4];
//4 structs and an array of 4 pointers to the stucts
//======================= MAIN ============================//
void main(void)
{
int8 i,n;
setup_adc_ports(NO_ANALOGS);
set_tris_a(0xFF);
set_tris_b(0xFF);
set_tris_c(0xFF);
set_tris_d(0xFF);
set_tris_e(0xFF);
p_pkt[0]=&Pkt0;
p_pkt[1]=&Pkt1;
p_pkt[2]=&Pkt2;
p_pkt[3]=&Pkt3;
//--------- START -------//
fprintf(DEBUG,"STARTING U11\n\r");
fprintf(DEBUG,"FIRMWARE VERSION %u.%02u\n\r",VER_MAJOR,VER_MINOR);
Pkt0.data[1]=0x1;
Pkt1.data[1]=0x2;
Pkt2.data[1]=0x3;
Pkt3.data[1]=0x4;
fprintf(DEBUG,"%X %X %X %X\n\r",Pkt0.data[1],Pkt1.data[1],Pkt2.data[1],Pkt3.data[1]);
fprintf(DEBUG,"----------\n\r");
for (i=0;i<4;i++)
{
fprintf(DEBUG,"%X \n\r",(p_pkt[i])->data[1]);
}
while(1){}
}
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treitmey
Joined: 23 Jan 2004
Posts: 1094
Location: Appleton,WI USA
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| Posted: Thu Nov 11, 2004 5:27 pm |
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| Can I simply not have 4 structs and a 4 elliment array of pointers to the struct? |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Thu Nov 11, 2004 8:22 pm |
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Just a stinky compiler 
| Code: |
for (i=0;i<4;i++)
{
fprintf(DEBUG,"%X \n\r", ((struct pkt*)p_pkt[i])->data[1]);
}
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treitmey
Joined: 23 Jan 2004
Posts: 1094
Location: Appleton,WI USA
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| Posted: Fri Nov 12, 2004 8:16 am |
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So if i understand.
You typecast p_pkt to be of type pointer to struc pkt.
and then you wraped the part in front of the structure pointer operator '->'
Got it.
Thanks |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Fri Nov 12, 2004 8:38 am |
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You got it.  |
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