Thanks for picking up that perl error. Fixed in the cvs. Paul
On 6/10/06, Jim Duda <[EMAIL PROTECTED]> wrote: > Paul, > > Ah, thanks for the description, very helpful. I'm almost there. > > I think I found a possible bug when reading the alarm values through the > perl interface. I can read the voltage, but not the alarm. > > When I do a perl get on "volt.X", all is good. > When I do a perl get on "alarm/low.X", I get a directory listing of the > alarm directory. > > From my print logs (perl): > > 06/10/06 09:49:27 AM Owfw_Item::get /20.DB2506000000/volt.B > data: 1.84003 > > 06/10/06 09:49:27 AM Owfw_Item::get /20.DB2506000000/alarm/low.B > data: high.ALL,high.A,high.B,high.C,high.D,low.ALL,low.A,low.B,low.C,low.D > > However, when I "cat 20.DB2506000000/alarm/low.B" via the file system, I > get the proper value of "0". > > Jim > > > Paul Alfille wrote: > > On 6/9/06, Jim Duda <[EMAIL PROTECTED]> wrote: > > > >>I measured the DC voltage, and discovered a cold solder joint on the > >>PCB. The DS2450 is reading voltage correctly now. > >> > >>Do the Alarms work? I don't follow how to set and/or detect an alarm. > >>I want to know if the voltage drops below 1V DC. > > > > I think they work -- easy enough to check. > > > >>I read the documentation, but it wasn't quite obvious what I should > >>be doing. > > > > > > I can see why the documentation was dissapointing. It hasn't been updated. > > I'll do that today and it can be read at > > http://www.owfs.org/index.php?page=ds2450 > > > > I believe the steps are > > > > 1. Set alarm limits, alarm enable and powered mode > > echo "1.0" > set_alarm/voltlow.A > > echo "1" > set_alarm/low.A > > echo "1" > power > > > > 2. Loop: > > while : ; do > > echo "1" > simultaneous/voltage > > ls alarm > > and look for it there > > done > > > > 3. Actually, all that is a rather silly way to do it if you don't have > > a lot of other 1-wire activity. > > Acording to my reading of the datasheet: > > http://pdfserv.maxim-ic.com/en/ds/DS2450.pdf > > Even powered, the DS2450 doesn't do continuous conversion, just allows > > other activity during conversion and speed up converions by .16 > > millseconds > > > > So you have to trigger a read. > > > > You can just poll the DS2450 and read the voltage and test. > > The real advantage of the scheme above with the "simultaneous" is that > > you don't need to pause during the conversion. > > I suspect the "alarm" directory would reflect a prior "simultaneous" > > since only a read would pause for it to be done, but that's ok. > > > > Does this answer your questions? > > > > Paul Alfille > > > > set "set_alarm/volthigh.A to "5.0" (so it won't trigger) > > for A through D, os use > > set "set_alarm/voltlow.ALL to "1.0,1.0,1.0,1.0" > > set "set_alarm/volthigh.ALL to "5.0,5.0,5.0,5.0" > > > > > > > >>I do have the DS2450 locally powered. I've set the POWER bit checkbox. > >>I also have the PIO check box set for the channels I want to monitor. > >> > >>Do the conversions happen continuously when power is set to true? Or, > >>only when I attempt to read the voltage? > >> > >>Thanks, > >> > >>Jim > >> > >>Paul Alfille wrote: > >> > >>>Can you test a DC voltage? It's always possible that we aren't reading > >>>voltages correctly. > >>> > >>>Paul Alfille > >>> > >>>On 6/9/06, Jim Duda <[EMAIL PROTECTED]> wrote: > >>> > >>> > >>>>Yes, 60 Hz. I would expect the capacitor to remain at some steady state > >>>>voltage, somewhere around 1.5V. I don't have access to an oscillosope at > >>>>home. > >>>> > >>>>Jim > >>>> > >>>> > >>>>"Paul Alfille" <[EMAIL PROTECTED]> wrote in message > >>>>news:[EMAIL PROTECTED] > >>>>Not at all off-topic. > >>>>I'm no expert, but the schematic is at > >>>>http://www.hobby-boards.com/catalog/links/hvac2-r1/HVAC%20Monitor%20v2.0%20Schematic.pdf > >>>> > >>>>With 1M resitor and 1uF capacitor, the time constant is 1 second. What is > >>>>the frequency of your AC? 60Hz? > >>>> > >>>>Paul Alfille > >>>> > >>>> > >>>>On 6/7/06, Jim Duda <[EMAIL PROTECTED]> wrote: > >>>> > >>>> > >>>>>I apologize if this is off topic, since owfs seems to handle DS2450 just > >>>>>fine, as best I can surmise. > >>>>> > >>>>>I purchased a "HVAC Monitor Kit" from Hobby Boards. The description of > >>>>>the board states that it can measure any voltage up to 28V AC or DC. > >>>>>The design has a diode and a resistive voltage divider (100K/1M) on the > >>>>>front-end of the DS2450 voltage inputs. > >>>>> > >>>>>For the signal I want to monitor, my DVM measures 15V AC at the terminal > >>>>>lug of the HVAC Monitor. However, via owfs HTTP, I see various voltages > >>>>>between 240 mV and 1.5V, seems to be all over the place, like maybe a > >>>>>sinusoid :-) > >>>>> > >>>>>Can anyone offer any tips on how I might measure an AC voltage with this > >>>>>thing? > >>>>> > >>>>>Jim > >>>>> > >>>>> > >>>>> > >>>>>_______________________________________________ > >>>>>Owfs-developers mailing list > >>>>>[email protected] > >>>>> > >>>> > >>>>https://lists.sourceforge.net/lists/listinfo/owfs-developers > >>>> > >>>> > >>>> > >>>> > >>>>________________________________ > >>>> > >>>> > >>>> > >>>> > >>>>________________________________ > >>>> > >>>> > >>>>_______________________________________________ > >>>> > >>>>Owfs-developers mailing list > >>>>[email protected] > >>>>https://lists.sourceforge.net/lists/listinfo/owfs-developers > >>>> > >>>> > >>>> > >>>> > >>>> > >>>> > >>>> > >>>>_______________________________________________ > >>>>Owfs-developers mailing list > >>>>[email protected] > >>>>https://lists.sourceforge.net/lists/listinfo/owfs-developers > >>>> > >>>> > >>>> > >> > >> > >> > >>_______________________________________________ > >>Owfs-developers mailing list > >>[email protected] > >>https://lists.sourceforge.net/lists/listinfo/owfs-developers > >> > > > > _______________________________________________ > Owfs-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/owfs-developers > _______________________________________________ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
