kd5uzz
Joined: 28 May 2006
Posts: 56
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| SPI missing chars? 4x4 Keypad -> 16F88 -> 16F877 |
 Posted: Sat Apr 21, 2007 10:32 am |
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I'm still working on my Keypad -> SPI encoder using an F88. Using the code below,if I enable RS232 output on the F88 I see every keypress, but the master only sees about 20 - 30% (even when RS232 output is disabled). When the master starts an SPI transaction it sends NULL as the data, if it receives the same value back then we know the slave didn't service the SPI transaction, i.e. there is no new keypress. Should I have pullup resistors on the SPI data lines?
Compiler 3.222
SPI Slave code:
| Code: |
#include <16F88.H>
#fuses INTRC_IO
#fuses NOWDT, BROWNOUT, NOLVP
#use delay(clock=500000)
#use rs232(baud=2400,xmit=PIN_B3,rcv=PIN_B3,ERRORS)
#include <flex_keypad_4x4.c>
//******************************
// Functions
//******************************
//******************************
// Global Defs
//******************************
//******************************
// Code
//******************************
void main(){
char k,spidata;
int BP = 0;
output_high(PIN_B7);
delay_ms(100);
output_low(PIN_B7);
delay_ms(100);
output_high(PIN_B7);
delay_ms(100);
output_low(PIN_B7);
kbd_init();
setup_spi(spi_slave | spi_l_to_h);
delay_ms(5);
printf("\n\r4x4 Keypad to SPI Converter");
while(TRUE){
k=kbd_getc();
if(k!=0){
output_high(PIN_B7);
//printf("Key: %i = '%c'\n\r sent to SPI...",k,k);
spidata = spi_read(k);
output_low(PIN_B7);
}
}
}
|
SPI Master code:
| Code: |
#include <16F877a.h>
#fuses HS,NOWDT,NOPROTECT,NOLVP
#use delay(clock=20000000) //clock speed
#use rs232(baud=2400,xmit=PIN_C6,rcv=PIN_C7,ERRORS)
#include "flex_lcd420.c"
#include <string.h>
//******************************
// Functions
//******************************
void SecondPassed();
int kbd_getc();
int waitforkbd();
void startup();
//******************************
// Global Defs
//******************************
#define LCD_BACKLIGHT_ON output_high(PIN_A0)
#define LCD_BACKLIGHT_OFF output_low(PIN_A0)
#define LED2_RED output_high(PIN_D6)
#define LED2_RED_OFF output_low(PIN_D6)
#define LED2_GREEN output_high(PIN_D7)
#define LED2_GREEN_OFF output_low(PIN_D7)
#define LED1_RED output_high(PIN_B3)
#define LED1_RED_OFF output_low(PIN_B3)
#define LED1_GREEN output_high(PIN_B4)
#define LED1_GREEN_OFF output_low(PIN_B4)
#define KEYPAD_ENABLE output_low(PIN_D4)
#define KEYPAD_DISABLE output_high(PIN_D4)
int BlinkState,SecondCount;
int LCDContrast = 24;
//******************************
// Code
//******************************
void Main(){
int i;
delay_ms(5);
startup();
while(TRUE){
KEYPAD_ENABLE;
i = spi_read(0);
KEYPAD_DISABLE;
if (i != 0){
printf("Key:%c ASCII: %d\n\r",i,i);
}
}
}
void startup(){
enable_interrupts(INT_TIMER2); //used to drive LED display
setup_timer_2(T2_DIV_BY_1, 130, 1);
setup_ccp1(CCP_PWM);
setup_spi(spi_master |spi_l_to_h | spi_clk_div_16 );
KEYPAD_DISABLE;
enable_interrupts(GLOBAL); //Actually enable them
//lcd_init();
//set_pwm1_duty(LCDContrast);
//LCD_BACKLIGHT_ON;
printf("\fKAB 1.0\nHardware Test 1.0\nSystem Online\nPlease Wait...");
delay_ms(2000);
//LCD_BACKLIGHT_OFF;
}
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