On Wed, Oct 23, 2013 at 10:42:05AM +0800, Andrew Elwell wrote: > Leaping in on this for ideas: > > > That said, the voltage drop should be *unevenly* distributed between Vcc > > and GND, so don't have 2 Vcc wires + 2 GND wires but rather 1 Vcc wire + > > 3 GND wires. Voltage drop on the Vcc line isn't "seen" by the bus > > protocol, on the GND wires it's causing problems. > > In my setup I'm planning on driving 20-30 DS18B20s along a piece of > ~20m cat5 (or higher) cable -- should I therefore use a couple of > spare paies as extra ground connections (such as the brown / w/brown > ones that would otherwise be unconnected?)
I would move the power to the other end of the cable if possible (you could use a 5V wallwart at the computer end and run it through a separate pair, with just a cap on the remote end). Better if you can put the wallwart at the remote end too (minimise crosstalk). njh ------------------------------------------------------------------------------ October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register > http://pubads.g.doubleclick.net/gampad/clk?id=60135991&iu=/4140/ostg.clktrk _______________________________________________ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
