Again, sorry for off-topic. You all are, however, the best 1W resource I know.
I indeed meant to specify powered. I started with the OneWire library and added in a few things. The actual code I'm using is here with a description of what I've been playing with: http://www.cupidcontrols.com/2014/10/moteino-arduino-and-1wire-optimize-your-read-for-speed/ At the moemnt, I am going to tell the thing to go do its other stuff until it's time to read scratchpad. Colin On 10/6/2014 14:45, Michael Markstaller wrote: > Hi Colin, > > this is really somewhat "off-topic" for owfs but well, we are a few here > knowing 1w for much more years than Arduino does, so I think it's ok.. > > Just curious: which code did you use? Most of what I've seen for 1w on > Arduino was - in terms of 8bit uC - fully broken or close to that.. > > wait, delay are methods for Java-People that dont care how much > resources they use. And if they get out of resources, asking their boss > for another Ghz, GB, Core/CPU :-) > > The first question is: powered or parasitic. In the latter case you > cannot mess around "low-level" with retries, this is very strictly timing. > Make your Convert_T, enable (strong-)pullup and wait (sleep) the given > time until reading the scratchpad. > If powered, don't expect the DS to tell the whole truth, from a very > "low-level" point of view, parasitic and powered are nearly the same for > a DS18x20.. > > Michael > > On 06.10.2014 23:02, Colin Reese wrote: >> Hello all, >> >> Here is an interesting wrinkle that is not really owfs, but is >> 1Wire-related, so I thought you might have some insight. >> >> I'm using OW on an arduino using the OneWire Library, and checking >> repeatedly after issuing a T Convert command with a DS18B20 to determine >> exactly when data is ready. This begins with instantiation of a OneWire >> object, a reset, match/select, a T Convert, and then with a repeated >> read command. When this returns 1, the data is ready. >> >> The question is this: if I recreate the object, is there any way to pick >> up where I left off checking if the data is ready? This of course would >> require a reset, which the device will ignore during conversion, but I >> assume also a Match. Does this then make it impossible to resume the >> data checking? Interestingly, reading scratchpad is successful even when >> reading during what should be the conversion window. I assume this is >> picking up stale data. >> >> The bottom line is that I have the possibility of multiple OneWire >> buses, want to avoid global OneWire objects and creating memory space >> for a whole bunch of them floating around. I think at the moment I'm >> just going to have to enforce a space of time between convert and read >> scratchpad, and then reinstantiate the object knowing that the data will >> be ready to read by the time I do so, based on the resolution and the >> datasheet. >> >> Suggestions welcome. >> Colin >> >> >> ------------------------------------------------------------------------------ >> Slashdot TV. Videos for Nerds. Stuff that Matters. >> http://pubads.g.doubleclick.net/gampad/clk?id=160591471&iu=/4140/ostg.clktrk >> _______________________________________________ >> Owfs-developers mailing list >> Owfs-developers@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/owfs-developers >> > > ------------------------------------------------------------------------------ Slashdot TV. Videos for Nerds. Stuff that Matters. http://pubads.g.doubleclick.net/gampad/clk?id=160591471&iu=/4140/ostg.clktrk _______________________________________________ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
