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
