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/*
* $Id$
*/
#include <avr/io.h>
#include <stdlib.h>
//include <sig-avr.h>
#include <avr/interrupt.h>
#include <avr/pgmspace.h>
#include "kb.h"
#include "serial.h"
#include "pindefs.h"
#include "scancodes.h"
#include "StdDefs.h"
#define BUFF_SIZE 64
// 02-Sep-2008 K. Schwichtenberg Timing modified for the avr-libc _delay_ms
unsigned char edge, bitcount; // 0 = neg. 1 = pos.
unsigned char kb_buffer[BUFF_SIZE];
unsigned char *inpt, *outpt;
unsigned char buffcnt;
void init_kb(void)
{
inpt = kb_buffer; // Initialize buffer
outpt = kb_buffer;
buffcnt = 0;
MCUCR = 2; // INT0 interrupt on falling edge
edge = 0; // 0 = falling edge 1 = rising edge
bitcount = 11;
}
SIGNAL(INT0_vect)
{
static unsigned char data; // Holds the received scan code
if (!edge) // Routine entered at falling edge
{
if(bitcount < 11 && bitcount > 2) // Bit 3 to 10 is data. Parity bit,
{ // start and stop bits are ignored.
data = (data >> 1);
if(PIND & 8)
data = data | 0x80; // Store a '1'
}
MCUCR = 3; // Set interrupt on rising edge
edge = 1;
} else { // Routine entered at rising edge
MCUCR = 2; // Set interrupt on falling edge
edge = 0;
if(--bitcount == 0) // All bits received
{
decode(data);
bitcount = 11;
}
}
// test_pin();
}
void decode(unsigned char sc)
{
static unsigned char is_up=0, shift = 0, mode = 0;
unsigned char i;
if (!is_up) // Last data received was the up-key identifier
{
switch (sc)
{
case 0xF0 : // The up-key identifier
is_up = 1;
break;
case 0x12 : // Left SHIFT
shift = 1;
break;
case 0x59 : // Right SHIFT
shift = 1;
break;
case 0x05 : // F1
if(mode == 0)
mode = 1; // Enter scan code mode
if(mode == 2)
mode = 3; // Leave scan code mode
break;
default:
if(mode == 0 || mode == 3) // If ASCII mode
{
if(!shift) // If shift not pressed,
{ // do a table look-up
for(i = 0; pgm_read_byte(&unshifted[i][0])!=sc
&& pgm_read_byte(&unshifted[i][0]); i++);
if (pgm_read_byte(&unshifted[i][0]) == sc) {
put_kbbuff(pgm_read_byte(&unshifted[i][1]));
}
} else { // If shift pressed
for(i = 0; pgm_read_byte(&shifted[i][0])!=sc && pgm_read_byte(&shifted[i][0]); i++);
if (pgm_read_byte(&shifted[i][0]) == sc) {
put_kbbuff(pgm_read_byte(&shifted[i][1]));
}
}
} else{ // Scan code mode
print_hexbyte(sc); // Print scan code
put_kbbuff(' ');
put_kbbuff(' ');
}
break;
}
} else {
is_up = 0; // Two 0xF0 in a row not allowed
switch (sc)
{
case 0x12 : // Left SHIFT
shift = 0;
break;
case 0x59 : // Right SHIFT
shift = 0;
break;
case 0x05 : // F1
if(mode == 1)
mode = 2;
if(mode == 3)
mode = 0;
break;
case 0x06 : // F2
clr();
break;
}
}
}
void put_kbbuff(unsigned char c)
{
if (buffcnt<BUFF_SIZE) // If buffer not full
{
*inpt = c; // Put character into buffer
inpt++; // Increment pointer
buffcnt++;
if (inpt >= kb_buffer + BUFF_SIZE) // Pointer wrapping
inpt = kb_buffer;
}
}
int getchar(void)
{
int byte;
while(buffcnt == 0) { // Wait for data
run_led(3000, 3000); // Timing changed / 10 K.Schwi
}
byte = *outpt; // Get byte
outpt++; // Increment pointer
if (outpt >= kb_buffer + BUFF_SIZE) // Pointer wrapping
outpt = kb_buffer;
buffcnt--; // Decrement buffer count
return byte;
}
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