Hi Ivan,
I'm using DS2482-100 with active pull-up done by a FET. This is able to
drive 89m IY(ST)Y, but I've never tried to remove the FET trying an strong
pull-up done by a resistor.
The DS2480-800 don't offer the addition output to be able to connect the
active pull-up FET, so you have are limited to use a strong pull-up.

I guess the OWFS does nothing to support this active pull-up, probably this
is completly done by the DS2482-100...

Regards
  Achim

On Mon, Apr 23, 2012 at 19:04, Ivan Lisenkov <i...@ivlis.com> wrote:

> I guess that active pullup will be great for long lines. Does owfs support
> it in case of
>  DS2482-x00?
>
> Best Regards,
>
> Ivan, PhD
>
>
>
>
> On Mon, Apr 23, 2012 at 4:11 PM, Nico Bouthoorn <n...@cuora.nl> wrote:
>
>> Found this:
>>
>> http://home.kpn.nl/thomas_7/1Wire/1wire_isolating.html
>>
>> Putting a driver after the DS2482-x00 give more reliability for long
>> lines?
>>
>> Nico
>>
>>
>> Ivan Lisenkov wrote:
>> > Now I am using DS9490R, but it is very unreliable. I now I have 6
>> > DS18B20, 2 D2406, DS2408 and 2 DS2438. The network is about 50m long
>> > (twisted pair, UTP-5). I can say, that DS9490R is totally not suitable
>> > for me. Devices appear and disappear randomly, same device appears
>> > multiple times, sometimes it is impossible to read or write a value.
>> > As I added one DS2438 more, network became unusable.
>> >
>> > It will be great if DS2482-x00 will be more reliable in long networks.
>> > I'll try to build adapter provided by Patryk and test it this week.
>> >
>> >
>> > Best Regards,
>> >
>> > Ivan, PhD
>> >
>> >
>> > On Mon, Apr 23, 2012 at 1:25 PM, Chris Lautre
>> > <chris.lau...@karusoft.com <mailto:chris.lau...@karusoft.com>> wrote:
>> >
>> >
>> >     I would be very interested in a USB to 1Wire Hub with 8 1 Wire
>> ports.
>> >     This would eb much better than using multiple DS9490R.
>> >
>> >     Chris
>> >
>> >
>> >     On 22/04/2012 10:42, Patryk wrote:
>> >     > I propose a new USB 1-wire adapter.
>> >     > The DS2490 native USB 1-wire adapter is no longer in production.
>> >     I think
>> >     > you can still buy built adapters from Hobbyboards but if You
>> >     want to build
>> >     > your own it's nearly impossible to source this chip. The popular
>> >     solution
>> >     > is to use DS2480B with some serial to USB converter like FT232
>> >     it behaves
>> >     > then like native DS2490. However if one plans to have w big 1-wire
>> >     > network with multiple branches the better way seems be
>> >     DS2482-800 which is
>> >     > basically a 1-wire master with one bus connected to a 8 port
>> >     hub. You can
>> >     > have then a star topology. Again You can still(not sure) buy a
>> >     hub from
>> >     > Hobbyborad to achieve the same goal but the hub chip is also out
>> of
>> >     > production. So if you are familiar with soldering iron this is a
>> >     solution
>> >     > for you.
>> >     >
>> >     > The DS2482-800 uses I2C bus. The conversion form I2C to USB is
>> >     handled by
>> >     > Atmega8A which is a 8 bit microcontroller and runs a special
>> >     program.
>> >     > It's a very popular chip it costs about $2(at least in Poland).
>> >     However
>> >     > You have to upload the firmware to it for which you need a
>> >     programmer. If
>> >     > you don't have one but you have an old PC with parallel port you
>> >     can build
>> >     > one with few resistors and a plug. Also Raspberry Pi can program
>> >     AVR chips.
>> >     > First I run i2c-tiny-usb
>> >     > http://www.harbaum.org/till/i2c_tiny_usb/index.shtml on Atmega8
>> >     > but there was a performance issue. The read from DS18B20 took
>> >     about 3
>> >     > seconds
>> >     > and without specifying the bus about 10. Compared to 1.5 with
>> >     DS2480 and
>> >     > similar
>> >     > time connected to vga i2c port.
>> >     > Fortunately there is a derivative project from Till's
>> >     i2-usb-tiny it's
>> >     > called OSFI(Open Source InterFace) . It's part of a project called
>> >     > OpenServo http://www.openservo.com/StepByStep
>> >     > It uses Atemga8 and has better performance because it uses some
>> >     built in
>> >     > i2c(do not know exactly).
>> >     >
>> >     > Here is the whole circuit. I think it's pretty explanatory. For
>> >     testing
>> >     > You can omit the voltage regulator and power it directly from
>> >     USB and not
>> >     > using the diodes should be fine for most computers. I done my
>> >     prototype on
>> >     > a breadboard and it works fine.
>> >     > http://ubuntuone.com/6uM1yQRB36zgGEFDxrTc7c
>> >     >
>> >     >
>> >     > On the 1-wire side DS9503 are not essential to get it running
>> >     they just
>> >     > protect the bus from electrostatic discharges. However they are
>> >     cheap. I
>> >     > used RJ-12 connectors (telephone) There are different standard's
>> >     of wiring
>> >     > the additional +5V the RJ45 are also popular. You can use screw
>> >     connectors
>> >     > as well. I think I will use 4 RJ45 for longer cables and if more
>> >     power is
>> >     > needed and RJ12 for thermometers.
>> >     >
>> >     > After assembling it on a breadboard You have to program the uC the
>> >     > firmware can be downloaded from OpenServo cvs.
>> >     >
>> >
>> http://www.openservo.com/viewcvs/OpenServo/Interfaces/OpenServo_InterFace/driver/Version_2/firmware/?root=cvs
>> >     > You need main.hex
>> >     > avrdude -c usbasp -p atmega8 -U lfuse:w:0x9f:m -U hfuse:w:0xc9:m
>> -U
>> >     > flash:w:main.hex
>> >     >
>> >     > Then you can test if it's recognized by the system
>> >     > lsusb shows
>> >     > Bus 001 Device 005: ID 1964:0001
>> >     > There is no name for it
>> >     >
>> >     > Then you have to compile kernel module
>> >     >
>> >
>> http://www.openservo.com/viewcvs/OpenServo/Interfaces/OpenServo_InterFace/driver/Version_2/kernel/?root=cvs
>> >     > make
>> >     > sudo make install
>> >     > sudo depmod -a
>> >     >
>> >     > sudo modprobe osif
>> >     >
>> >     > sudo modprobe i2c-dev
>> >     >
>> >     > then
>> >     > sudo i2cdetect -l
>> >     > should show something like this
>> >     > i2c-0 i2c OSIF at bus 001 device 005 I2C adapter
>> >     >
>> >     > Then you can run owfs
>> >     > sudo owfs –i2c=/dev/i2c-0 /mnt/owfs
>> >     > You can also use the parameter
>> >     > --i2c=ALL:ALL and owfs will look at every i2c device. However
>> >     there is
>> >     > some bug in older version an you might get segmentation fault.
>> >     It is now
>> >     > fixed in CVS
>> >     >
>> >     > The you should get something like this
>> >     > sudo ls /mnt/owfs
>> >     > bus.0
>> >     > bus.1
>> >     > bus.2
>> >     > bus.3
>> >     > bus.4
>> >     > bus.5
>> >     > bus.6
>> >     > bus.7
>> >     > settings
>> >     > structure
>> >     > uncached
>> >     > statistics
>> >     > system
>> >     >
>> >     > Here's the whole Eagle project the board is half done
>> >     > http://ubuntuone.com/32tUJtqRyNr3ngTsApwW83
>> >     > and how it looks like on a breadboard
>> >     > http://ubuntuone.com/0CUuACUSJMW69aK2FznM6i
>> >     >
>> >     >
>> >     > Pleas give tips how to improve this tutorial. The board is on
>> >     the way.
>> >     >
>> >
>> >
>> ------------------------------------------------------------------------------
>> >     For Developers, A Lot Can Happen In A Second.
>> >     Boundary is the first to Know...and Tell You.
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>> >
>> >
>> >
>> >
>> >
>> ------------------------------------------------------------------------------
>> > For Developers, A Lot Can Happen In A Second.
>> > Boundary is the first to Know...and Tell You.
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>> >
>> >
>> > _______________________________________________
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>> > https://lists.sourceforge.net/lists/listinfo/owfs-developers
>>
>>
>>
>> ------------------------------------------------------------------------------
>> For Developers, A Lot Can Happen In A Second.
>> Boundary is the first to Know...and Tell You.
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>> http://p.sf.net/sfu/Boundary-d2dvs2
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>>
>
>
>
> ------------------------------------------------------------------------------
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> Boundary is the first to Know...and Tell You.
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>
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