Am Donnerstag, 28. April 2016 19:40:19 UTC+2 schrieb [email protected]: > > Hello! > > *1. Max sensors* > When I try: > echo 20 > w1_master_max_slave_count > > I get: > bash: w1_master_max_slave_count: Permission denied > (of course I´m root > sudo su echo 20 > w1_master_max_slave_count exit
> *2. Polling time* > Well, 19sec in total is OK! It are just room temperatur and this must not > update so fast. But can I add more as 10 sensors because of Point 3? > > *3. max cable length* > I mean the total cable length of the 1-Wire bus ... when I connect in > Daisy-Chain I have around 50m to the last 1-Wire sensor. > Of course, it depends on the electro-magnetic pollution in your area. Ie. frequency converters with heavy loads are crititcal. I read about networks with a weight of 200 m using additional w1 drivrer chips with 5V power supply. But I didn't test it. It's recommended to avoid Daisy-Chain configuration. Instead think about a tree structure: one root connected to the master and several terminals with short wiring to the slaves or further terminals. More than 20 sensors shouldn't be an issue when the radius is small (< 20 m, when I tried a radius of 25 m in my system, I had to reduce the pullup from 4k7 to 3k3.) 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/00d85114-addc-4423-abcf-68d1b3b8426e%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
