Code for DS18b20 instead DS1820

[niculescu_dann]

I made the great project of "Digital thermostat (080090-11)" from Elektor july_august 2008 ; unfortunate I do not have DS1820 but DS18B20. The temperature show on display is like "xxx.xx 'C" !.
I read this : "In order to convert the HEX code to a temperature value, first you need to identify if you are using a DS18S20, or DS18B20 series sensor. The code to read the temperature needs to be slightly different for the DS18B20 (and DS1822), because it returns a 12-bit temperature value (0.0625 deg precision), while the DS18S20 and DS1820 return 9-bit values (0.5 deg precision)".
Can somebody help me to modify the source for using DS18B20 ?
Thanks in advance !

[Elektor Editor]

Have a look at the project called "Thermo-Snake" from the June 2008 issue. This is based on the DS18B20.

Good luck.

Jan

[niculescu_dann]

I write, based on information from web, four variants of code, for use with DS18B20. Enjoy !
1.OWOut DQ, 1, [$CC, $BE]
OWIn DQ, 2, [Temperature.Lowbyte, Temperature.Highbyte]
Convert_Temp:
Dummy = 625 * Temperature
TempC = DIV32 10
TempC = (Temperature & $7FF) >> 4
Float = ((Temperature.Lowbyte & $0F ) * 25 )>>2
Temperature = TempC*100 + Float

2.OWOut DQ, 1, [$CC, $BE]
OWIn DQ, 2, [RAWTEMP.Lowbyte, RAWTEMP.Highbyte]
Convert_Temp:
dummy = RAWTEMP * 625
TempC = DIV32 100
Temperature = TempC

3.OWOut DQ, 1, [$CC, $BE]
OWIn DQ, 2, [Temperature.Lowbyte, Temperature.Highbyte]
Convert_Temp:
TempC = (Temperature & $7FF) >> 4
Float = ((Temperature.Lowbyte & $0F ) * 25 )>>2
Temperature = TempC*100 + Float

4.OWOut DQ, 1, [$CC, $BE]
OWIn DQ, 0, [Temperature.LowByte, Temperature.HighByte, Skip 4, Count_Remain, Count_Per_C]
Convert_Temp :
Temperature = (((Temperature >> 1) * 100) - 25) + (((Count_Per_C - Count_Remain) * 100) / Count_Per_C)
if Temperature > 32767 then '32767 check if BIT12=1
Temperature= ~Temperature
temperature=temperature>>3 ; divide by 8

[billbar]

I write, based on information from web, four variants of code, for use with DS18B20. Enjoy !
1.OWOut DQ, 1, [$CC, $BE]
OWIn DQ, 2, [Temperature.Lowbyte, Temperature.Highbyte]
Convert_Temp:
Dummy = 625 * Temperature
TempC = DIV32 10
TempC = (Temperature & $7FF) >> 4
Float = ((Temperature.Lowbyte & $0F ) * 25 )>>2
Temperature = TempC*100 + Float

2.OWOut DQ, 1, [$CC, $BE]
OWIn DQ, 2, [RAWTEMP.Lowbyte, RAWTEMP.Highbyte]
Convert_Temp:
dummy = RAWTEMP * 625
TempC = DIV32 100
Temperature = TempC

3.OWOut DQ, 1, [$CC, $BE]
OWIn DQ, 2, [Temperature.Lowbyte, Temperature.Highbyte]
Convert_Temp:
TempC = (Temperature & $7FF) >> 4
Float = ((Temperature.Lowbyte & $0F ) * 25 )>>2
Temperature = TempC*100 + Float

4.OWOut DQ, 1, [$CC, $BE]
OWIn DQ, 0, [Temperature.LowByte, Temperature.HighByte, Skip 4, Count_Remain, Count_Per_C]
Convert_Temp :
Temperature = (((Temperature >> 1) * 100) - 25) + (((Count_Per_C - Count_Remain) * 100) / Count_Per_C)
if Temperature > 32767 then '32767 check if BIT12=1
Temperature= ~Temperature
temperature=temperature>>3 ; divide by 8

[germanroot]

Hi Niculescu,

I hope you can help me.

I like to use the Universal Thermostat 16F628
from 2008-07-08, but the software I can not download
as before in Elektor, if I search for the software 080090-11 or 080090-11.zip,
Elektor only want selling the PCB-Board or the programmed PIC.

I want programming and edit by myself, I have tons of new PIC MCU's
and maybe I can find a programming partner to modify for a new
option.

Please help me to find or download the Elektor software, maybe I can
get the file from you, becuase in the magazine they wrote : free download !!!

My email address is : asiabroadcasting@hotmail.de

I would be happy to get any respons from you, thanks.

Best regards,

Albert Schweitzer