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 >
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