pointer to structure array from main.c?

S

Steve

Hi,
I have a keypad that I am scanning to get key states, and am putting
those states in a structure. 16 keys, so I have it like
keys[0].status=PRESSSED. to keys[16].status etc.

I can access the elements in keypad.c, but why can't I see it from
main.c? It says I need a pointer type, but I can't figure it out yet.

Can someone show me how to access my key information from main.c?
Thankyou. Here are relevant files

*********************main.c***********************************
#include "includes.h" //which includes keypad.h
//KEY *pKey; //commented out
//pKey = &keys;
//*pKEY = &KEY;

//init I/O for keypad
keypad_init();
while(1){
temp =scankeypad();
temp =scankeypad();
if(keys(1).status==KEYPRESSED){// ***This line gives me an error,
wheras in the keypad.c file I can access this. Gives, must have a
pointer to type function.
fprintf(pntr1, "Key1pressed");
}else{
fprintf(pntr1, "Key1Notpressed");
}

}


**********************keypad.h*********************************/

#include <includes.h>

#ifndef __KEYPAD_H
#define __KEYPAD_H
#define KEYDOWN 1
#define KEYUP 0
#define MAXDOWNCOUNT 100
#define KEYPRESSED 1
#define KEYNOTPRESSED 0



typedef struct keys {
unsigned char state;
unsigned int downcount;
unsigned char status;
}KEY;


typedef enum {//BIT POSITIONS OF KEYS IN keysdown
UP = 0, //SW4
DOWN, //SW8
ENTER, //SW12
BACK, //SW16
SW5,
SW9,
SW13,
SW17,
SW6,
SW10,
SW14,
SW18,
SW7,
SW11,
SW15,
SW19,
STRIPSWITCH
} keyname;


/* Declare functions */
void keypad_init(void);
unsigned int scankeypad(void);
//void getStatusForKey(struct key *pkey);
#endif

**********************keypad.C*********************************/

#include "keypad.h"
/***********************************************************
* Function:
*
***********************************************************/



//setup I/O of matrix. Internal Pullups on Rows which are inputs.

#define row0 (1<<16)
#define row1 (1<<17)
#define row2 (1<<18)
#define row3 (1<<19)
#define col0 (1<<20)
#define col1 (1<<21)
#define col2 (1<<22)
#define col3 (1<<23)

void keypad_init(){

IO1DIR |= 0x00f00000;//make rows inputs and columns outputs
1=output, 0 = input
IO1DIR &= 0xfff0ffff;//make columns outputs

//FIO1DIR2 is bits16-23 of port1 which are the rows and columns
//Set all high, and pull columns low to see which row key is
pressed.
/*
P1_16 // Row0 = GPIO
P1_17 // Row1 = GPIO
P1_18 // Row2 = GPIO
P1_19 // Row3 = GPIO

P1_20 // Col0 = GPIO
P1_21 // Col1 = GPIO
P1_22 // Col2 = GPIO
P1_23 // Col3 = GPIO
*/
/*while(1){

IO1CLR |= (col0 | col1 | col2 | col3);
}*/
}//keypad_init


unsigned int scankeypad(void){
unsigned int keysdown=0;
unsigned int temp=0;
unsigned char colbit, rowbit,keybit=0;

KEY keys[10];

IO1SET |= (col0 | col1 | col2 | col3);// set all columns high at
first

for(colbit=20;colbit<24;colbit++){
IO1CLR |= (1<<colbit);//set a column low

for(rowbit=16;rowbit<20;rowbit++){
temp=(IO1PIN & (1<<rowbit));
if(temp==0){//if this row is low update keysdown
keysdown |= (1<<keybit); //place 1's in down key positions,
bit0 is first scanned
keys[keybit].state=KEYDOWN;
if(keys[keybit].downcount<MAXDOWNCOUNT ){
keys[keybit].downcount++;
}else{
if(keys[keybit].downcount==MAXDOWNCOUNT){
keys[keybit].status=KEYPRESSED;
}
}
}else{ //key is up
keysdown =keysdown & ~(0<<keybit);//place 0's in up keypad bit
positions
keys[keybit].status=KEYNOTPRESSED;
keys[keybit].downcount=0;
keys[keybit].state=KEYUP;
}
keybit++;
}
IO1SET |= (1<<colbit);//set the column back high
}
return keysdown;
}
 
S

Steve

Hi,
I have a keypad that I am scanning to get key states, and am putting
those states in a structure. 16 keys, so I have it like
keys[0].status=PRESSSED. to keys[16].status etc.

I can access the elements in keypad.c, but why can't I see it from
main.c? It says I need a pointer type, but I can't figure it out yet.

Can someone show me how to access my key information from main.c?
Thankyou. Here are relevant files
Click to expand...

Joachim, Thankyou very much. I totally missed that () as opposed to
[]. I did have the extern up top at one point, but I can't believe
you caught that subtle error.
Thankyou,
Steve (I accidentally deleted the response by mistake, but I did get
and compile it now.)
 
J

Joachim Schmitz

Steve said:
Hi,
I have a keypad that I am scanning to get key states, and am putting
those states in a structure. 16 keys, so I have it like
keys[0].status=PRESSSED. to keys[16].status etc.

I can access the elements in keypad.c, but why can't I see it from
main.c? It says I need a pointer type, but I can't figure it out yet.

Can someone show me how to access my key information from main.c?
Thankyou. Here are relevant files

*********************main.c***********************************
#include "includes.h" //which includes keypad.h
//KEY *pKey; //commented out
//pKey = &keys;
//*pKEY = &KEY;

//init I/O for keypad
keypad_init();
while(1){
temp =scankeypad();
temp =scankeypad();
if(keys(1).status==KEYPRESSED){// ***This line gives me an error,
Click to expand...
if (keys[1].status==KEYPRESSED) { /* need to use [], not ()*/
/* Beginning of main() is missing as well as an extern KEY keys[]; */
wheras in the keypad.c file I can access this. Gives, must have a
pointer to type function.
fprintf(pntr1, "Key1pressed");
}else{
fprintf(pntr1, "Key1Notpressed");
}

}


**********************keypad.h*********************************/

#include <includes.h>

#ifndef __KEYPAD_H
#define __KEYPAD_H
#define KEYDOWN 1
#define KEYUP 0
#define MAXDOWNCOUNT 100
#define KEYPRESSED 1
#define KEYNOTPRESSED 0



typedef struct keys {
unsigned char state;
unsigned int downcount;
unsigned char status;
}KEY;


typedef enum {//BIT POSITIONS OF KEYS IN keysdown
UP = 0, //SW4
DOWN, //SW8
ENTER, //SW12
BACK, //SW16
SW5,
SW9,
SW13,
SW17,
SW6,
SW10,
SW14,
SW18,
SW7,
SW11,
SW15,
SW19,
STRIPSWITCH
} keyname;


/* Declare functions */
void keypad_init(void);
unsigned int scankeypad(void);
//void getStatusForKey(struct key *pkey);
#endif

**********************keypad.C*********************************/

#include "keypad.h"
/***********************************************************
* Function:
*
***********************************************************/



//setup I/O of matrix. Internal Pullups on Rows which are inputs.

#define row0 (1<<16)
#define row1 (1<<17)
#define row2 (1<<18)
#define row3 (1<<19)
#define col0 (1<<20)
#define col1 (1<<21)
#define col2 (1<<22)
#define col3 (1<<23)

void keypad_init(){

IO1DIR |= 0x00f00000;//make rows inputs and columns outputs
1=output, 0 = input
IO1DIR &= 0xfff0ffff;//make columns outputs

//FIO1DIR2 is bits16-23 of port1 which are the rows and columns
//Set all high, and pull columns low to see which row key is
pressed.
/*
P1_16 // Row0 = GPIO
P1_17 // Row1 = GPIO
P1_18 // Row2 = GPIO
P1_19 // Row3 = GPIO

P1_20 // Col0 = GPIO
P1_21 // Col1 = GPIO
P1_22 // Col2 = GPIO
P1_23 // Col3 = GPIO
*/
/*while(1){

IO1CLR |= (col0 | col1 | col2 | col3);
}*/
}//keypad_init


unsigned int scankeypad(void){
unsigned int keysdown=0;
unsigned int temp=0;
unsigned char colbit, rowbit,keybit=0;

KEY keys[10];

IO1SET |= (col0 | col1 | col2 | col3);// set all columns high at
first

for(colbit=20;colbit<24;colbit++){
IO1CLR |= (1<<colbit);//set a column low

for(rowbit=16;rowbit<20;rowbit++){
temp=(IO1PIN & (1<<rowbit));
if(temp==0){//if this row is low update keysdown
keysdown |= (1<<keybit); //place 1's in down key positions,
bit0 is first scanned
keys[keybit].state=KEYDOWN;
if(keys[keybit].downcount<MAXDOWNCOUNT ){
keys[keybit].downcount++;
}else{
if(keys[keybit].downcount==MAXDOWNCOUNT){
keys[keybit].status=KEYPRESSED;
}
}
}else{ //key is up
keysdown =keysdown & ~(0<<keybit);//place 0's in up keypad bit
positions
keys[keybit].status=KEYNOTPRESSED;
keys[keybit].downcount=0;
keys[keybit].state=KEYUP;
}
keybit++;
}
IO1SET |= (1<<colbit);//set the column back high
}
return keysdown;
}
Click to expand...
 
J

Joachim Schmitz

Steve said:
Hi,
I have a keypad that I am scanning to get key states, and am putting
those states in a structure. 16 keys, so I have it like
keys[0].status=PRESSSED. to keys[16].status etc.

I can access the elements in keypad.c, but why can't I see it from
main.c? It says I need a pointer type, but I can't figure it out yet.

Can someone show me how to access my key information from main.c?
Thankyou. Here are relevant files
Click to expand...

Joachim, Thankyou very much. I totally missed that () as opposed to
[]. I did have the extern up top at one point, but I can't believe
you caught that subtle error.
Click to expand...
I've made enough of these mistakes myself 8.)

Bye, Jojo
 

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