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DS18b20 don' work

Posted: Sat Jan 28, 2012 3:45 pm
by JakobRasmussen
Hello.
I can not get a DS18b20 singel to work. I've tried with many examples from FC4 forums.
The display shows all kinds of things, just not what it should. There is no reaction when the temperature rises. I remembered 4.7 k resistor. I've tried with other DS18B20 and microcontrollers.
To be sure that my hardware, and the installation of FC5 is okay
Is there anyone who will make program, and upload the FCF-file + the corresponding hex file, to this forums.
Then I upload the hex file to my controller in a different way.
You must be sure that it works!
Sensor DS18b20 C
Micro Controllers must be 16F88, 16F690 or 16F877A.
Clock frequency must be internal.
LCD board is a standard.

Best regards
JakobRasmussen.

Re: DS18b20 don' work

Posted: Sat Jan 28, 2012 6:02 pm
by kersing
Have you made sure to use ds18B20 example code and not ds18S20 code? The two devices are not the same from a code point of view. (Examples for the ds1820 will not work as that device is equivalent to the ds18s20 with regards to code)

Re: DS18b20 don' work

Posted: Sat Jan 28, 2012 7:02 pm
by STibor
8MHz clock ds18b20 the necessary work.

Re: DS18b20 don't work

Posted: Tue Jan 31, 2012 9:15 pm
by JakobRasmussen
Thank Kersing and Stibor. I have no DS18S20, but I have DS1820 and DS18B20.
I changed the clock speed to 8 Mhz, and it helped. http://www.matrixmultimedia.com/mmforum ... 29&t=10125#
I do not think I've read here in this forums that DS18(x)20 only could operate at 8 MHz. Maybe FC support will explain whether it is right.
Should all "one-wire" running 8 Mhz?
My next project is to communicate with "Real Clock" and 16F690.
I've attached my FCF-file "It is a Flow Code 5" with the comment.