154 lines
2.9 KiB
C
154 lines
2.9 KiB
C
/*
|
|
ADB to USB-converter, for a non-extended keyboard and a mouse
|
|
Copyright (C) 2010 Jeroen Domburg
|
|
|
|
This program is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation, either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
#define F_CPU 12000000
|
|
#include <util/delay.h>
|
|
#include <avr/io.h>
|
|
#include <avr/interrupt.h>
|
|
#include <stdio.h>
|
|
#include <avr/pgmspace.h>
|
|
#include <string.h>
|
|
#include "adb.h"
|
|
|
|
|
|
#define ADB_H() DDRB&=~(1<<ADBPIN)
|
|
#define ADB_L() DDRB|=(1<<ADBPIN)
|
|
#define ADBVAL (PINB&(1<<ADBPIN))
|
|
|
|
static void adbSendOne(void) {
|
|
ADB_L();
|
|
_delay_us(35);
|
|
ADB_H();
|
|
_delay_us(65);
|
|
}
|
|
|
|
static void adbSendZero(void) {
|
|
ADB_L();
|
|
_delay_us(65);
|
|
ADB_H();
|
|
_delay_us(35);
|
|
}
|
|
|
|
static void adbAttnSync(void) {
|
|
ADB_L();
|
|
_delay_us(800);
|
|
ADB_H();
|
|
_delay_us(70);
|
|
}
|
|
|
|
static void adbSendByte(unsigned char byte) {
|
|
unsigned char p;
|
|
for (p=0; p<8; p++) {
|
|
if (byte&128) adbSendOne(); else adbSendZero();
|
|
byte<<=1;
|
|
}
|
|
}
|
|
|
|
//Includes stop byte
|
|
static void adbSendTlt(void) {
|
|
adbSendZero();
|
|
ADB_H();
|
|
// _delay_us(165); //165 is according to spec
|
|
_delay_us(100);
|
|
}
|
|
|
|
static char adbWaitStart(void) {
|
|
int x=200;
|
|
//Wait till line goes low.
|
|
_delay_us(1);
|
|
while (ADBVAL && x>0) {
|
|
x--;
|
|
_delay_us(1);
|
|
}
|
|
if (x==0) return 0;
|
|
|
|
//Delay for the low time of the start bit
|
|
_delay_us(40);
|
|
//Should be high again...
|
|
if (!ADBVAL) return 0;
|
|
//Wait till the line goes low again for the 1st databit.
|
|
while(ADBVAL && x>0) {
|
|
x--;
|
|
_delay_us(1);
|
|
}
|
|
if (x==0) return 0;
|
|
//Ok, all good.
|
|
return 1;
|
|
}
|
|
|
|
static char adbGetBit(void) {
|
|
char res=0;
|
|
int x;
|
|
// DDRD|=(1<<3);
|
|
// PIND=(1<<3);
|
|
_delay_us(50);
|
|
// PIND=(1<<3);
|
|
if (ADBVAL) res=1;
|
|
x=80;
|
|
while(!ADBVAL && x>0) {
|
|
_delay_us(1);
|
|
x--;
|
|
}
|
|
while(ADBVAL && x>0) {
|
|
_delay_us(1);
|
|
x--;
|
|
}
|
|
if (x==0) return -1;
|
|
return res;
|
|
}
|
|
|
|
static unsigned char adbGetByte(void) {
|
|
unsigned char ret, b, x;
|
|
for (x=0; x<8; x++) {
|
|
ret<<=1;
|
|
b=adbGetBit();
|
|
if (b==-1) return 0xff;
|
|
if (b==1) ret|=1;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
|
|
int adbCommand(unsigned char cmd, unsigned char *data, int size) {
|
|
int x;
|
|
adbAttnSync();
|
|
adbSendByte(cmd);
|
|
adbSendTlt();
|
|
if (cmd&C_TALK) {
|
|
//Device writes data
|
|
if (!adbWaitStart()) return -1;
|
|
for (x=0; x<size; x++) data[x]=adbGetByte();
|
|
} else {
|
|
//We write data.
|
|
_delay_us(200);
|
|
adbSendOne();
|
|
for (x=0; x<size; x++) adbSendByte(data[x]);
|
|
adbSendOne();
|
|
}
|
|
return size;
|
|
}
|
|
|
|
void adbReset(void) {
|
|
PORTD&=~(1<<ADBPIN);
|
|
|
|
//Reset bus
|
|
ADB_L();
|
|
_delay_ms(3);
|
|
ADB_H();
|
|
_delay_ms(2);
|
|
}
|