DS18B20

[dedajozo]

Hello,

I'm triing to make DS18B20 termometer, chip si running with 10mhz external crystal, 4,7k resistor is connected but program is not working. Only it writes sometimes 7.5 or 0.
In the attachment is program. I tried to make termometer with LM35 an everything works fine..

Thank you in advance

[Benj]

Hello,

Is this any better? I removed one of your calculation icons which I don't think was required.

TermometarDS18B20.fcfx

(8.2 KiB) Downloaded 410 times

[dedajozo]

Hello Benj,

now I have value 127,5, and nothing hapends.

[Benj]

Hello,

Your microcontroller speed may also be a bit low, 10MHz on a PIC is probably too slow to reliably do 1-wire comms. Can you run the PIC at 20MHz instead? This should then hopefully work correctly.

[jgu1]

Hi!

I managed to get Ben´s example to work with a Pic16f877A and a 19.xx MHz Xtal signal. In on D1. I also use some calculation from an old DS18B20 project from Flowcode 5.

You remember pullup resistor

It work nice by me. Maybe this work by you. Good luck.

But Ben, if you see this? If I import this program in FC7 it does not work.??

Br
Jorgen

[celebriums]

Hi Jgi

Will you try the attached file? My circuit in my running smoothly.

[jgu1]

Hi again!

Do you test mine??

Your new program work fine by me also. I dare to change a little on your program.

Br

Jorgen

[dedajozo]

Thank you all I will try it.

[dedajozo]

Hello,

I tried all versions with 20 mhz crystal but it is not working.