On Sun, Jan 16, 2011 at 6:30 AM, vasile surducan <[email protected]>wrote:
> > > On Sun, Jan 16, 2011 at 2:36 AM, Joep Suijs <[email protected]> wrote: > >> Hi Vasi, >> >> > The device is exactly DS18B20 >> How can you be sure? >> > > Because this code does not work with DS18s20, I'm using both since about 10 > years... > > Joep, I forgot something important. If you're trying to use long wire, the behavior you'll find looks like a software bug, sometime the temperature read is 0 instead of real temp... Check out this, if you have a few meter 1w bus, use twisted wires (or cat5) between the bus and ground and another pair for VCC and ground. Use a terminal pull-up resistor smaller than indicated in the datasheet (you can go down to 1.5K without any problem) at the end of the bus and at least 100nF near the DS package. BTW I hope you don't have DS18S20...because this one is ugly. Vasile -- You received this message because you are subscribed to the Google Groups "jallib" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/jallib?hl=en.
