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vuphanhuan
Joined: 19 Jun 2010
Posts: 3
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| Keypad, LCD and 16F887 |
 Posted: Sun Jun 20, 2010 3:37 am |
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Dear CCS Friend!
I copied source code of keypad driver from CCS forum for my project.
when i check LCD to display, that is ok. But I press button on keypad, I can not get any thing. Please help me and explain why is it. I am looking to hear from friends soon.
| Code: |
///////////////////////////////////////////////////////////////////////////
//// Flex_KBD.C ////
//// Generic keypad scan driver ////
//// ////
//// kbd_init() Must be called before any other function. ////
//// ////
//// c = kbd_getc(c) Will return a key value if pressed or /0 if not ////
//// This function should be called frequently so as ////
//// not to miss a key press. ////
//// ////
///////////////////////////////////////////////////////////////////////////
//The PCH compiler defines this pre-processor identifier. It may be used to determine if the PCH compiler is doing the compilation.
//Keypad connection:
#define col0 PIN_B0
#define col1 PIN_B1
#define col2 PIN_B2
#define row0 PIN_B4
#define row1 PIN_B5
#define row2 PIN_B6
#define row3 PIN_B7
// Keypad layout:
char const KEYS[4][3] = {{'1','2','3'},
{'4','5','6'},
{'7','8','9'},
{'*','0','#'}};
#define KBD_DEBOUNCE_FACTOR 33 // Set this number to apx n/333 where
// n is the number of times you expect
// to call kbd_getc each second
void kbd_init() {
port_b_pullups(true);
}
short int ALL_ROWS (void)
{
if (input (row0) & input (row1) & input (row2) & input (row3))
return (0);
else
return (1);
}
char kbd_getc( ) {
static byte kbd_call_count;
static short int kbd_down;
static char last_key;
static byte col;
byte kchar;
byte row;
kchar='\0';
if(++kbd_call_count>KBD_DEBOUNCE_FACTOR) {
switch (col) {
case 0 : output_low(col0);
output_high(col1);
output_high(col2);
break;
case 1 : output_high(col0);
output_low(col1);
output_high(col2);
break;
case 2 : output_high(col0);
output_high(col1);
output_low(col2);
break;
}
if(kbd_down) {
if(!ALL_ROWS()) {
kbd_down=false;
kchar=last_key;
last_key='\0';
}
} else {
if(ALL_ROWS()) {
if(!input (row0))
row=0;
else if(!input (row1))
row=1;
else if(!input (row2))
row=2;
else if(!input (row3))
row=3;
last_key =KEYS[row][col];
kbd_down = true;
} else {
++col;
if(col==3)
col=0;
}
}
kbd_call_count=0;
}
return(kchar);
}
///------------------------------------
#include <16F887.H>
//#fuses XT, NOWDT, NOPROTECT, BROWNOUT, PUT, NOLVP
#use delay(clock = 4000000)
//#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7, ERRORS)
#use rs232(baud=9600)
#include <flex_lcd.c>
#define use_portb_kbd TRUE
#include <flex_kbd.c>
//========================
void main()
{
char k;
kbd_init();
lcd_init();
lcd_gotoxy(1,1);
printf(lcd_putc,"testing keypad");
delay_ms(2000);
while(TRUE)
{
k=kbd_getc();
lcd_gotoxy(1,2);
printf(lcd_putc,"Boton = %c", k);
delay_ms(500);
}
} |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19504
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| Posted: Sun Jun 20, 2010 4:20 am |
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The point is that keys are not 'got', and waiting for you to read. You need to be _looping_ calling kbd_getc, _unitl_ it returns a key.
So:
| Code: |
void main() {
char k;
kbd_init();
lcd_init();
lcd_gotoxy(1,1);
printf(lcd_putc,"testing keypad");
delay_ms(2000);
while(TRUE) {
k=0;
while (k==0) { //Loop waiting for the key
k=kbd_getc();
delay_ms(1);
}
lcd_gotoxy(1,2);
printf(lcd_putc,"Boton = %c", k);
//delay_ms(500); //No point in this, get back to scanning
//the keys ASAP.
}
}
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vuphanhuan
Joined: 19 Jun 2010
Posts: 3
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| Posted: Sun Jun 20, 2010 5:11 am |
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Dear Ttelmah!
I tried with looping calling kbd_getc(). so, the "Botom =" name don't display or k=kbd_getc() do not working. I use resistor 10k on B4, B5, B6, B7 and Vcc=5V. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Sun Jun 20, 2010 11:18 am |
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| Code: |
#define row2 PIN_B6
#define row3 PIN_B7
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Pins B6 and B7 are used by the ICD debugger/programmer. Do you
have the ICD plugged into the board ? The debugger has 4.7K pull-down
resistors inside it, on those signal lines. This will reduce the voltage
of your pull-up resistors to an inadequate level.
Un-plug the ICD debugger before testing your program.
Or better, don't use pins B6 and B7 for anything, if possible. Use two
different pins for the keypad. |
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vuphanhuan
Joined: 19 Jun 2010
Posts: 3
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| Posted: Mon Jun 21, 2010 3:34 am |
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| At moment I use to simulate by Proteus 7.5 and I changed row 2 = A6, row3 = A7. But it do not display what button pressed. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Mon Jun 21, 2010 12:43 pm |
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Pins A6 and A7 are used for the oscillator. If you want to use them as
normal i/o pins for the LCD, then you need to use the INTRC_IO fuse.
Are you using that fuse ?
My advice is to download the 16F887 data sheet and look at the pin
diagram for the PIC, and choose some i/o pins that are not used by
http://ww1.microchip.com/downloads/en/DeviceDoc/41291F.pdf
Also look at the pin descriptions in this table. It will help you to decide
which pins to use:
| Quote: | | TABLE 1-2: PIC16F884/887 PINOUT DESCRIPTION |
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