Keyb.C and 18F452!!!

[picker]

Has any one had any problems using the keyb.c and a 18F452. I get it to work, but it reacts very strangly. I press a button and nothing happens, I then press several and then suddenly a character is displayed. Then it works well for two or three characters (Shows the chars correctly on the LCD) and then nothing happens again when I press a key. I then press several keys and again it would display all the keys and the hook again.

I have had the same reaction on a 18F7820 and I though it was a silicon bug, but obviously its something in the software. I have checked the connections to the Pic and all seems fine. Also the mapping to the PIC is the same as in Keyb.c (I changed Keyb.c to suit the keyboard I am using.)

I have commented all the code of the Keyb.c which selects the port and the key mapping and replaced it with the following...

#byte kbd = 0xF83
#define set_tris_kbd(x) set_tris_d(x)

#define COL0 (1 << 2)
#define COL1 (1 << 1)
#define COL2 (1 << 0)

#define ROW0 (1 << 6)
#define ROW1 (1 << 5)
#define ROW2 (1 << 4)
#define ROW3 (1 << 3)

Here follows my code in the main program...

In header file ....

#include <18F452.h>
#device adc=8
#use delay(clock=4000000)
#use rs232(baud=9600,parity=n,xmit=PIN_C6,rcv=PIN_C7)
#fuses HS,NOWDT,WDT1,NOLVP

In C file ........

#device PIC18F452
#include "C:\Program Files\Picc\R50_keyboard\r50_key.h"
#include "c:\Program Files\Picc\R50_keyboard\LCD.C"
#include "c:\Program Files\Picc\R50_keyboard\kbd.C"

char k;

void main() {

output_high(PIN_E1);
setup_adc_ports(NO_ANALOGS);
setup_adc(ADC_OFF);
setup_psp(PSP_DISABLED);
setup_spi(FALSE);
setup_wdt(WDT_OFF);
setup_timer_0(RTCC_INTERNAL);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);
setup_timer_3(T3_DISABLED|T3_DIV_BY_1);

lcd_init();
kbd_init();

lcd_putc("\fReady...\n");

while (TRUE)
{
delay_ms(10);
k=kbd_getc();


if(k!=0)
{
printf(lcd_putc,"\f");
printf(lcd_putc,"Char :%C",k);
}

}



}

[PCM programmer]

The file KBD.C has the following comment:

[picker]

I thought I'd add this to the topic....


I did have resistors on the cols, but they were 5k resistors and as a last resort I tried 10k resistors and IT WORKED!!!!!!!!!!!!!!!!! Thanks to PCM Programmer!!!!

I realise if I read the datasheets of the PIC I would have noticed that the 5k resistors would be too low for the PIC to pull the output down to 0.

picker