/*
* Copyright (c) 2005, Swedish Institute of Computer Science
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of the Contiki operating system.
*
* @(#)$Id: ds1820.c,v 1.5 2010/08/25 18:35:52 nifi Exp $
*/
/*
* Device driver for the Dallas Semiconductor DS1820 chip. Heavily
* based on the application note 126 "1-Wire Communications Through
* Software".
*
* http://www.maxim-ic.com/appnotes.cfm/appnote_number/126
*/
/*
* For now we stuff in Moteiv Corporation's unique OUI.
* From http://www.ethereal.com/distribution/manuf.txt:
* 00:12:75 Moteiv # Moteiv Corporation
*
* The EUI-64 is a concatenation of the 24-bit OUI value assigned by
* the IEEE Registration Authority and a 40-bit extension identifier
* assigned by the organization with that OUI assignment.
*/
#include <avr/io.h>
#include <string.h>
#include "contiki.h"
#include "ds1820.h"
unsigned char ds1820_id[8];
unsigned char ds1820_ok[8];
/* 1-wire is at PortE.3 */
#define SERIAL_ID_PIN_READ PINE
//#define SERIAL_ID_PIN_MASK _BV(PE3)
#define SERIAL_ID_PIN_MASK _BV(PE4)
#define SERIAL_ID_PxOUT PORTE
#define SERIAL_ID_PxDIR DDRE
#define SET_PIN_INPUT() (SERIAL_ID_PxDIR &= ~SERIAL_ID_PIN_MASK)
#define SET_PIN_OUTPUT() (SERIAL_ID_PxDIR |= SERIAL_ID_PIN_MASK)
#define OUTP_0() (SERIAL_ID_PxOUT &= ~SERIAL_ID_PIN_MASK)
#define OUTP_1() (SERIAL_ID_PxOUT |= SERIAL_ID_PIN_MASK)
#define PIN_INIT() do{ \
SET_PIN_INPUT(); \
OUTP_0(); \
} while(0)
/* Drive the one wire interface low */
#define OW_DRIVE() do { \
SET_PIN_OUTPUT(); \
OUTP_0(); \
} while (0)
/* Release the one wire by turning on the internal pull-up. */
#define OW_RELEASE() do { \
SET_PIN_INPUT(); \
OUTP_1(); \
} while (0)
/* Read one bit. */
#define INP() (SERIAL_ID_PIN_READ & SERIAL_ID_PIN_MASK)
/*
* Delay times in us.
*/
#define tA 6 /* min-5, recommended-6, max-15 */
#define tB 64 /* min-59, recommended-64, max-N/A */
#define tC 60 /* min-60, recommended-60, max-120 */
#define tD 10 /* min-5.3, recommended-10, max-N/A */
#define tE 9 /* min-0.3, recommended-9, max-9.3 */
#define tF 55 /* min-50, recommended-55, max-N/A */
#define tG 0 /* min-0, recommended-0, max-0 */
#define tH 480 /* min-480, recommended-480, max-640 */
#define tI 70 /* min-60.3, recommended-70, max-75.3 */
#define tJ 410 /* min-410, recommended-410, max-N/A */
/*---------------------------------------------------------------------------*/
#define udelay(u) clock_delay_usec(u)
/*---------------------------------------------------------------------------*/
static int
owreset(void)
{
int result;
OW_DRIVE();
udelay(tH); /* 480 < tH < 640 */
OW_RELEASE(); /* Releases the bus */
udelay(tI);
result = INP();
udelay(tJ);
return result;
}
/*---------------------------------------------------------------------------*/
static void
owwriteb(unsigned byte)
{
int i = 7;
do {
if(byte & 0x01) {
OW_DRIVE();
udelay(tA);
OW_RELEASE(); /* Releases the bus */
udelay(tB);
} else {
OW_DRIVE();
udelay(tC);
OW_RELEASE(); /* Releases the bus */
udelay(tD);
}
if(i == 0) {
return;
}
i--;
byte >>= 1;
} while(1);
}
/*---------------------------------------------------------------------------*/
static unsigned
owreadb(void)
{
unsigned result = 0;
int i = 7;
do {
OW_DRIVE();
udelay(tA);
OW_RELEASE(); /* Releases the bus */
udelay(tE);
if (INP()){
result |= 0x80; /* LSbit first */
}
udelay(tF);
if(i == 0) {
return result;
}
i--;
result >>= 1;
} while(1);
}
/*---------------------------------------------------------------------------*/
/* Polynomial ^8 + ^5 + ^4 + 1 */
static unsigned
crc8_add(unsigned acc, unsigned byte)
{
int i;
acc ^= byte;
for(i = 0; i < 8; i++) {
if(acc & 1) {
acc = (acc >> 1) ^ 0x8c;
} else {
acc >>= 1;
}
}
return acc;
}
/*---------------------------------------------------------------------------*/
int
ds1820_init()
{
int i;
unsigned family, crc, acc;
PIN_INIT();
if(owreset() == 0) { /* Something pulled down 1-wire. */
owwriteb(0x33); /* Read ROM command. */
family = owreadb();
/* We receive 6 bytes in the reverse order, LSbyte first. */
for(i = 7; i >= 2; i--) {
ds1820_id[i] = owreadb();
}
crc = owreadb();
/* Verify family DS1820 and that CRC match. */
if(family != 0x10) {
goto fail;
}
acc = crc8_add(0x0, family);
for(i = 7; i >= 2; i--) {
acc = crc8_add(acc, ds1820_id[i]);
}
if(acc == crc) {
ds1820_id[0] = 0x00;
ds1820_id[1] = 0x00;
ds1820_id[2] = 0x00;
return 1; /* Success! */
}
} else {
}
fail:
memset(ds1820_id, 0x0, sizeof(ds1820_id));
return 0; /* Fail! */
}
/*---------------------------------------------------------------------------*/
int
ds1820_temp()
{
ds1820_convert();
// wait max 750ms pin lo
clock_wait(CLOCK_SECOND);
ds1820_read();
return 1;
}
int
ds1820_convert()
{
unsigned i;
PIN_INIT();
for(i=0;i<3;i++){
if(owreset() == 0) { /* Something pulled down 1-wire. */
owwriteb(0xCC); /* Skip ROM command. */
owwriteb(0x44); /* Convert T command. */
OW_RELEASE(); /* Releases the bus */
return 1;
} else {
}
}
return 0; /* Fail! */
}
/*---------------------------------------------------------------------------*/
int
ds1820_read()
{
int i;
unsigned crc, acc;
if(owreset() == 0) { /* Something pulled down 1-wire. */
owwriteb(0xCC); /* Skip ROM command. */
owwriteb(0xBE); /* Read Scratchpad command. */
/* We receive 8 bytes in the reverse order, LSbyte first. */
for(i = 0; i < 8; i++) {
ds1820_id[i] = owreadb();
}
crc = owreadb();
acc=0;
for(i = 0; i < 8; i++) {
acc = crc8_add(acc, ds1820_id[i]);
}
if(acc == crc) {
// store temp
for(i = 0; i < 8; i++) {
ds1820_ok[i]=ds1820_id[i];
}
return 1; /* Success! */
} else {
return 0; /* Fail! */
}
} else {
return 0; /* Fail! */
}
return 1; /* Fail! */
}