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. >> > Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! >> > http://p.sf.net/sfu/Boundary-d2dvs2 >> > _______________________________________________ >> > Owfs-developers mailing list >> > Owfs-developers@lists.sourceforge.net >> > <mailto:Owfs-developers@lists.sourceforge.net> >> > 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. >> > Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! >> > http://p.sf.net/sfu/Boundary-d2dvs2 >> > >> > >> > _______________________________________________ >> > Owfs-developers mailing list >> > Owfs-developers@lists.sourceforge.net >> > 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. >> Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! >> http://p.sf.net/sfu/Boundary-d2dvs2 >> _______________________________________________ >> Owfs-developers mailing list >> Owfs-developers@lists.sourceforge.net >> 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. > Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! > http://p.sf.net/sfu/Boundary-d2dvs2 > > _______________________________________________ > Owfs-developers mailing list > Owfs-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/owfs-developers > >
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