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hansolo
Joined: 06 Oct 2006
Posts: 20
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| DS18S20 & DS18B20 Codes |
 Posted: Fri Oct 06, 2006 6:56 pm |
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I find that the codes available in this site for DS18S20 & DS18B20 is a bit messy and complicated.
Below is the simple version of the codes which works. It also take care of negative temperature.
However, due to its simplicity, this will only work with one DS1820 connected to the 1-wire bus of the PIC. This code will not work with 2 or more DS1820 sharing the same 1-wire bus.
1wire.c
| Code: |
// (C) copyright 2003 j.d.sandoz / jds-pic !at! losdos.dyndns.org
// released under the GNU GENERAL PUBLIC LICENSE (GPL)
// refer to http://www.gnu.org/licenses/gpl.txt
// 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 2 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, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
/***********************1Wire Class***********************/
/*Description: This class handles all communication */
/* between the processor and the 1wire */
/* sensors.
/*********************************************************/
/*-------1-wire definitions-------*/
#define ONE_WIRE_PIN PIN_A0
/*******************1-wire communication functions********************/
/************onewire_reset*************************************************/
/*This function initiates the 1wire bus */
/* */
/*PARAMETERS: */
/*RETURNS: */
/*********************************************************************/
void onewire_reset() // OK if just using a single permanently connected device
{
output_low(ONE_WIRE_PIN);
delay_us( 500 ); // pull 1-wire low for reset pulse
output_float(ONE_WIRE_PIN); // float 1-wire high
delay_us( 500 ); // wait-out remaining initialisation window.
output_float(ONE_WIRE_PIN);
}
/*********************** onewire_write() ********************************/
/*This function writes a byte to the sensor.*/
/* */
/*Parameters: byte - the byte to be written to the 1-wire */
/*Returns: */
/*********************************************************************/
void onewire_write(int data)
{
int count;
for (count=0; count<8; ++count)
{
output_low(ONE_WIRE_PIN);
delay_us( 2 ); // pull 1-wire low to initiate write time-slot.
output_bit(ONE_WIRE_PIN, shift_right(&data,1,0)); // set output bit on 1-wire
delay_us( 60 ); // wait until end of write slot.
output_float(ONE_WIRE_PIN); // set 1-wire high again,
delay_us( 2 ); // for more than 1us minimum.
}
}
/*********************** read1wire() *********************************/
/*This function reads the 8 -bit data via the 1-wire sensor. */
/* */
/*Parameters: */
/*Returns: 8-bit (1-byte) data from sensor */
/*********************************************************************/
int onewire_read()
{
int count, data;
for (count=0; count<8; ++count)
{
output_low(ONE_WIRE_PIN);
delay_us( 2 ); // pull 1-wire low to initiate read time-slot.
output_float(ONE_WIRE_PIN); // now let 1-wire float high,
delay_us( 8 ); // let device state stabilise,
shift_right(&data,1,input(ONE_WIRE_PIN)); // and load result.
delay_us( 120 ); // wait until end of read slot.
}
return( data );
}
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ds1820.c
| Code: |
float ds1820_read()
{
int8 busy=0, temp1, temp2;
signed int16 temp3;
float result;
onewire_reset();
onewire_write(0xCC);
onewire_write(0x44);
while (busy == 0)
busy = onewire_read();
onewire_reset();
onewire_write(0xCC);
onewire_write(0xBE);
temp1 = onewire_read();
temp2 = onewire_read();
temp3 = make16(temp2, temp1);
result = (float) temp3 / 2.0; //Calculation for DS18S20 with 0.5 deg C resolution
// result = (float) temp3 / 16.0; //Calculation for DS18B20 with 0.1 deg C resolution
delay_ms(200);
return(result);
}
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Main code
| Code: |
#include <16F877A.h>
#device *=16
#device adc=8
#FUSES NOWDT, HS, PUT, NOPROTECT, NODEBUG, BROWNOUT, NOLVP, NOCPD, NOWRT
#use delay(clock=20000000)
#include<1wire.c>
#include<lcd.c>
#include<ds1820.c>
void main()
{
float temperature;
setup_adc_ports(NO_ANALOGS);
setup_adc(ADC_OFF);
setup_psp(PSP_DISABLED);
setup_spi(FALSE);
setup_timer_0(RTCC_INTERNAL|RTCC_DIV_1);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);
setup_comparator(NC_NC_NC_NC);
setup_vref(VREF_LOW|-2);
lcd_init();
lcd_putc("\f");
while (1)
{
temperature = ds1820_read();
lcd_gotoxy(1,1);
printf(lcd_putc,"TEMP: %3.1f ", temperature);
lcd_putc(223);
lcd_putc("C ");
lcd_gotoxy(1,2);
if(temperature >= 29.0)
printf(lcd_putc,"Hot! ");
else if( temperature >= 20 && temperature < 29.0)
printf(lcd_putc,"Comfort!");
else
printf(lcd_putc,"Cold! ");
}
}
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Last edited by hansolo on Sun Oct 15, 2006 5:56 pm; edited 1 time in total |
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jds-pic
Joined: 17 Sep 2003
Posts: 205
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| Re: DS18S20 & DS18B20 Codes |
| Posted: Wed Oct 11, 2006 3:02 pm |
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| hansolo wrote: | I find that the codes available in this site for DS18S20 & DS18B20 is a bit messy and complicated.
Below is the simple version of the codes which works. It also take care of negative temperature. |
the entirety of the onewire driver code is copied directly from my post of Fri Jun 04, 2004 9:54 am EST -- a post which noted that the attached code is covered under the GPL.
http://ccsinfo.com/forum/viewtopic.php?t=19520
you can read about the GPL here
http://www.gnu.org/licenses/gpl.txt
jds-pic |
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hansolo
Joined: 06 Oct 2006
Posts: 20
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| Posted: Wed Oct 11, 2006 3:43 pm |
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I posted the codes for sharing and I am not selling it.
I hope you do not mind.
Thanks. |
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jds-pic
Joined: 17 Sep 2003
Posts: 205
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| Posted: Sun Oct 15, 2006 1:34 pm |
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| hansolo wrote: | I posted the codes for sharing and I am not selling it.
I hope you do not mind.
Thanks. |
you must carry forward the GPL license and as well as the copyright(s) of the original author(s).
jds-pic |
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hansolo
Joined: 06 Oct 2006
Posts: 20
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| Posted: Sun Oct 15, 2006 5:52 pm |
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| jds-pic wrote: | | hansolo wrote: | I posted the codes for sharing and I am not selling it.
I hope you do not mind.
Thanks. |
you must carry forward the GPL license and as well as the copyright(s) of the original author(s).
jds-pic |
My mistake. I did not read the fine print.
I will amend it.
Sorry. |
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ulaska
Joined: 16 Jul 2007
Posts: 3
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| Posted: Mon Jul 16, 2007 3:08 pm |
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i tried this codes. it works OK.
i use 2x16 standard LCD, DS1280 and pic16f876a.
but it shows the temperatures like, 25.4 , 25.9, 27.4 ,
it increases or decreases 0.5 degree.
the resolution is 0.5 degree, but it isnt whole numbers or half (25.0, 25.5 etc.)
i think there are some problems with data types in ds1820_read() ?
but i cannot see any mistake, also i tried to add 0.1 to reach whole numbers  but doesnt works.
thank you.
p.s. i am new in PICs |
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scanan
Joined: 13 Aug 2004
Posts: 58
Location: Turkey
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| 0.1 degree resolution working code |
| Posted: Wed Jan 16, 2008 4:29 pm |
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A working modification of hansolo - jds-pic codes.
Now it works fine.
| Code: | // onewire library, for dallas onewire devices
// currently includes:
// - generic onewire functions (init, readbyte, sendbyte, crc, etc.)
// - ds1822 dallas-semi econo-thermometer
// (C) copyright 2003 j.d.sandoz / jds-pic !at! losdos.dyndns.org
// released under the GNU GENERAL PUBLIC LICENSE (GPL)
// refer to http://www.gnu.org/licenses/gpl.txt
// 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 2 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, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//Previously Posted in CCS thread from jds-pic
//Revision Made By SCanan Date: 26.06.2007
#include <16f628.h>
#device *=16
// internal osilator used
#FUSES NOWDT,INTRC, NOPUT, NOPROTECT, NOBROWNOUT, NOMCLR, NOLVP, NOCPD//for 16f628
#use delay(clock=4000000)
#USE RS232(BAUD=9600, XMIT=PIN_B2, RCV=PIN_B1)
#include "1wire.c"
int8 tH,tL,Conf;
float ds1820_read()
{
int8 busy=0, temp1, temp2;
signed int16 temp3;
float result;
onewire_reset();
onewire_write(0xCC);
onewire_write(0x44);
delay_ms(200);
while (busy == 0)
busy = onewire_read();
onewire_reset();
onewire_write(0xCC);
onewire_write(0xBE);
temp1 = onewire_read();
temp2 = onewire_read();
tH=onewire_read();
tL=onewire_read();
Conf=onewire_read();
temp3 = make16(temp2, temp1);
//result = (float) temp3 / 2.0; // 0.5 deg C resolution
result = (float) temp3 / 16.0; //0.1 deg C resolution
delay_ms(200);
return(result);
}
void main()
{
float temperature;
setup_timer_0(RTCC_INTERNAL|RTCC_DIV_1);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);
//for 10 bit resolution mod
onewire_write(0xCC);
onewire_write(0x4E);
onewire_write(125);
onewire_write(-55); //this should be done for proper working of DS18B20
onewire_write(127);
onewire_reset();
onewire_write(0xCC);
onewire_write(0x48);
delay_ms(15);
while (1)
{
temperature = ds1820_read();
printf("Temperature= %3.1f\n\r",temperature);
}
}
////// 1wire.c fontion //////
///// DS18b20 data pin connected to pic16f628 B0 pin //////
/***********************1Wire Class***********************/
/*Description: This class handles all communication */
/* between the processor and the 1wire */
/* sensors.
/*********************************************************/
/*-------1-wire definitions-------*/
#define ONE_WIRE_PIN PIN_B0
/*******************1-wire communication functions********************/
void onewire_reset() // OK if just using a single permanently connected device
{
output_low(ONE_WIRE_PIN);
delay_us( 500 ); // pull 1-wire low for reset pulse
output_float(ONE_WIRE_PIN); // float 1-wire high
delay_us( 500 ); // wait-out remaining initialisation window.
output_float(ONE_WIRE_PIN);
}
/*********************** onewire_write() ********************************/
/*This function writes a byte to the sensor.*/
/* */
/*Parameters: byte - the byte to be written to the 1-wire */
/*Returns: */
/*********************************************************************/
void onewire_write(int data)
{
int count;
for (count=0; count<8; ++count)
{
output_low(ONE_WIRE_PIN);
delay_us( 2 ); // pull 1-wire low to initiate write time-slot.
output_bit(ONE_WIRE_PIN, shift_right(&data,1,0)); // set output bit on 1-wire
delay_us( 60 ); // wait until end of write slot.
output_float(ONE_WIRE_PIN); // set 1-wire high again,
delay_us( 2 ); // for more than 1us minimum.
}
}
/*********************** read1wire() *********************************/
/*This function reads the 8 -bit data via the 1-wire sensor. */
/* */
/*Parameters: */
/*Returns: 8-bit (1-byte) data from sensor */
/*********************************************************************/
int onewire_read()
{
int count, data;
for (count=0; count<8; ++count)
{
output_low(ONE_WIRE_PIN);
delay_us( 2 ); // pull 1-wire low to initiate read time-slot.
output_float(ONE_WIRE_PIN); // now let 1-wire float high,
delay_us( 8 ); // let device state stabilise,
shift_right(&data,1,input(ONE_WIRE_PIN)); // and load result.
delay_us( 120 ); // wait until end of read slot.
}
return( data );
} |
Last edited by scanan on Tue Apr 08, 2014 1:55 pm; edited 3 times in total |
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mthornton
Joined: 22 Jan 2008
Posts: 4
Location: Canal Flats BC
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| Posted: Thu Feb 21, 2008 3:56 pm |
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The above ds18s20 code is nice & light & works, but I avoided the floating variables by integer-multiplying the result by 5 instead of dividing by 2 or 16. So my result is in DegC x 10. No problem, makes it even lighter. Just have to remember where to place the decimal-point in the display routine.
instead of the lines:
float ds1820_read()
float result
result = (float) temp3 / 2.0;
used :
signed int16 ds1820_read()
signed int16 result
result = temp3 * 5; |
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40inD
Joined: 30 Jul 2007
Posts: 112
Location: Moscow, Russia
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| Posted: Sat Apr 26, 2008 1:08 pm |
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Why i get 0.5 degree resolution in 18B20 when i do this:
| Code: | | result = (float) temp3 / 16.0; |
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meereck
Joined: 09 Nov 2006
Posts: 173
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| Posted: Tue Apr 29, 2008 4:42 am |
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hello, thanx for the source code. Works like a charm with both DS18S20 and B. Can any1 tell me what the maximal length of a cable between a PIC and the sensor can be?
cheers meereck |
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noobprogrammer
Joined: 20 May 2008
Posts: 5
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| ds18s20 |
| Posted: Tue May 20, 2008 7:07 pm |
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| meereck wrote: | hello, thanx for the source code. Works like a charm with both DS18S20 and B. Can any1 tell me what the maximal length of a cable between a PIC and the sensor can be?
cheers meereck |
anybody has the schematic for this? thanks |
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muerte
Joined: 19 May 2008
Posts: 8
Location: Poland
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| Re: ds18s20 |
| Posted: Wed May 21, 2008 3:40 am |
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Hi all,
| noobprogrammer wrote: | | meereck wrote: | hello, thanx for the source code. Works like a charm with both DS18S20 and B. Can any1 tell me what the maximal length of a cable between a PIC and the sensor can be?
cheers meereck |
anybody has the schematic for this? thanks |
Schematic?
Look this:
/*-------1-wire definitions-------*/
#define ONE_WIRE_PIN PIN_B0
connect DS18S20 to this pin (or another defined)
and DS18S20 data sheet from Maxim http://datasheets.maxim-ic.com/en/ds/DS18S20.pdf
_________________
Best regards,
muerte |
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meereck
Joined: 09 Nov 2006
Posts: 173
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| Re: ds18s20 |
| Posted: Wed May 21, 2008 7:08 am |
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| muerte wrote: | Hi all,
| noobprogrammer wrote: | | meereck wrote: | hello, thanx for the source code. Works like a charm with both DS18S20 and B. Can any1 tell me what the maximal length of a cable between a PIC and the sensor can be?
cheers meereck |
anybody has the schematic for this? thanks |
Schematic?
Look this:
/*-------1-wire definitions-------*/
#define ONE_WIRE_PIN PIN_B0
connect DS18S20 to this pin (or another defined)
and DS18S20 data sheet from Maxim http://datasheets.maxim-ic.com/en/ds/DS18S20.pdf |
In addition, do not forget the pull-up resistor on the data line |
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ckielstra
Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands
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noobprogrammer
Joined: 20 May 2008
Posts: 5
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| Re: ds18s20 |
| Posted: Wed May 21, 2008 7:35 pm |
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| muerte wrote: | Hi all,
| noobprogrammer wrote: | | meereck wrote: | hello, thanx for the source code. Works like a charm with both DS18S20 and B. Can any1 tell me what the maximal length of a cable between a PIC and the sensor can be?
cheers meereck |
anybody has the schematic for this? thanks |
Schematic?
Look this:
/*-------1-wire definitions-------*/
#define ONE_WIRE_PIN PIN_B0
connect DS18S20 to this pin (or another defined)
and DS18S20 data sheet from Maxim http://datasheets.maxim-ic.com/en/ds/DS18S20.pdf |
will this work for the pic18f452? and which ports and pins are connected to the LCD..sorrie im a noob..thanks for your help! |
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