Hi David, That it worked on its own and not in the final configuration reminds me on our old problems.
How do you wire the whole thing? twisted pair or telephone cabling? Shielded? I had the experience that the USB-1w-adaptor (those blue devices you can get from Maxim) has a higher tolerance for malformed signals. Have you tried a laptop with usb adaptor? We did the following things (in that order): - put filters in (that is documented somewhere on the Maxim pages, I can dig out the layout if you want) - changed the timings on the bus to the timings suggested by Maxim (for usb that is in owserver, owlib etc., --altusb option), you can achieve the same thing by assigning some values in the /owfs dir tree) - chained all the devices using network cabling, before that we had a bus/star mixed topology telephone-wire network. The part of the network which is still old-fashioned is driven by an usb-adaptor (the rest is connected via a terminal server and a RS232-1w adaptor). Layouts (most words are in German) are here: http://www.aip.de/People/ wbittner/1wire/index.html Michael On 09.08.2007, at 10:40, David Toy wrote: > Hey Guys! > > Thanks very much for your quick responses. I have looked at my wiring. > I have to admit that that's where I initially though the problem might > be. > > My DS2423 has Vdd power (5v). The counter inputs are held high by a > pull up resistor. The switch is a hall effect switch which, when > closed, connects the counter inputs to ground. The voltage levels for > this is 5v switch open, 0.6v switch closed, both of which are > acceptable according to the datasheet. The switch is a binary state > device so floating levels should not exist. > > I have created my own board for the DS2480B to connect it to the UART > of the WRT54G and the correct values recorded by my thermometers > (DS18S20) suggests that this is working. > > I seem to remember that this chip worked fine when tested on its own, > but now that it is on a PCB and a bus with the thermometers I get > these annoying Data Error problems. > > I am not overly familiar with the bus protocol, but could the addition > of the (parasitic) thermometers have a detrimental effect on the bus > during long transfers? I say long transfers because I assume that a > page of memory in the DS2423 is read during transactions, and that > this is more data than is transferred for a thermometer reading? > If so is there anything I could do to improve the bus? > > I was concerned that the chip might be dead. But when queried it gives > some correct (?) values: > address: 1DC70B090000003A > counters.ALL: "Error: Invalid argument" > counters.A: "Error: Invalid argument" > counters.B: "Error: Invalid argument" > crc8: 3A > family: 1D > id: C70B09000000 > locator: FFFFFFFFFFFFFFFF > memory: "Error: Invalid argument" > mincount: "Error: Invalid argument" > pages: [link to pages] > present: YES > r_address: 3A000000090BC71D > r_id: 000000090BC7 > r_locator: FFFFFFFFFFFFFFFF > type: DS2423 > > Could anyone suggest some useful debugging commands that might help to > pinpoint the fault? > > Thanks Again, > > David > > ---------------------------------------------------------------------- > --- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a > browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > _______________________________________________ > Owfs-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/owfs-developers > ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
