Please help with code for DS18B20

[fratello]

Read first page of THIS topic !!!

[Ioannis]

Every device on 1-Wire network has in its internal EEPROM a unique serial number that has to be known to the host.

Otherwise the host can not find the device and communicate.

On Maxim site there is an application note about a way to automatically find the devices on the local 1-wire network. SO every time your controller powers up, it makes an device scan and stores the found ID's or serial numbers.


The second method is to find the serial numbers by your self and store them in the internl EEPROM of the controller.


AN187, is the Note that describes the method

Ioannis

[astanapane]

Fratello and Ioannis,

thanks for your help.

Now i understand. It is very similar to RFID serial number. You can retrieve the serial from the device.

I will make a small program to retrieve the serial from the device and place it to the code.

i will come back with my results.

Best Regards,

[fratello]

I will make a small program to retrieve the serial from the device and place it to the code.

It's in post #22. Enjoy !

[astanapane]

Hi Fratello,

here we are step by step.

i did retrieve the serial number from the DS18B20. I placed it to the code and worked.

I put two sensors and now i have INT and EXT temp. I can say that they are really close the temp from two sensors.

Now i would like to ask you if the code is for the temp only or the thermostat.

I have place two LED on the porta.2 and porta.3, but i dont see any light.

Do i need to configure anything else?

[fratello]

Good job ! Keep it so !
You need to add these lines :

If V < TargetTemp - Hyst then ' Below Target temperature - Hysteresis
PORTA.2=1 ' Activate Warm Output
PORTA.3=0 ' Deactivate Cold Output
EndIf

If V > TargetTemp + Hyst then ' Above Target temperature + Hysteresis
PORTA.2=0 ' Deactivate Warm output
PORTA.3=1 ' Activate Cold Output
EndIf

just in front of

GoSub SelectSign ' +/blank/- Sign
GoSub DisplayTemp ' Temperature to LCD


Goto MainLoop ' Do it forever

[astanapane]

Hi Fratello,

your help is much appreciated.

I will follow your instructions this afternoon. The code is working really well and the temperatures are very close to other circuits i have.

Thanks a lot!!!