Hi! Am Donnerstag, 28. April 2016 15:52:40 UTC+2 schrieb [email protected]: > > Hello, > > I want to use 1-wire DS18B20+ sensors with the BBB. > On my breadcrump is work with 2 sensors. > > My question: > with: > cat w1_bus_master1/w1_master_max_slave_count > he show me max 10 sensors ... why? >
AFAIR this is a default value in the kernel driver. You can echo a larger number in order to override it. > I need around 25 sensors with a wire length of 50m. > > Is this possible? > > I use all 3 wires (GND, VCC (5V) and Data) > When you sample 25 sensors by the kernel driver, each conversation takes about 750 ms, in total ~19 seconds. So your process must not have high temperatur gradients. You can speed up conversations by broadcast triggering (~1 second in total). This isn't supported by the kernel driver. What do you mean by cable length? The weight or the radius? > > - The radius of a network is the wire distance from the master end to > the most distant slave. > - The weight of a network is the total amount of connected wire in the > network. > > In a thermal solar system I use eight sensors with a bus radius of 15 m and a weight of 45 m (BBB GPIO, no additional hardware, simple cable and RJ12 connectors). BR -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/5808ab70-1a32-4d85-a4af-444c96b23540%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
