Hi Michaël, Are you using 18ohm pull up resistor as your wiring diagram states? If so this resistor is too low for pull up; both bone and sensor will have to sink a lot of current to drive the line down.
See this discussion here: https://groups.google.com/forum/#!topic/beaglebone/dosKmEE7xso Gerald told a beaglebone pin can sink around 6mA, but using Ohm's Law to find current over a 18ohms resistor while driven by 3.3V voltage source we find 0.183A or 183mA. The discussion pointed above talk about 1K resistor, this would result in 3.3/1000 = 0.0033 or 3.3mA. Your beaglebone and sensor might have not enough strength to hold the Data line down (GND) and because of this there is no communication. This also can damage the bone pin, so for test try another pin with 1k resistor pull up. Regards, Benito On Sat, Sep 6, 2014 at 10:10 AM, Michaël Vaes <vaesmich...@gmail.com> wrote: > Changing the OS to Ubuntu did not change the behaviour. > Any help is appreciated on debugging this. > > Thanks! > *Michael* > > > On Saturday, August 30, 2014 1:01:18 PM UTC+2, Michaël Vaes wrote: >> >> Hi - >> >> I'm stuck getting my DS18B20 temperature sensor working on my Beaglebone >> Black. I installed and loaded the DTC overlay but Im not getting the '28-*' >> files in my '/sys/devices/w1_bus_master1/' directory. >> >> *Wiring* >> https://dl.dropboxusercontent.com/u/97513059/ds18b20- >> temperature-sensor.pdf >> > -- *Josenivaldo Benito Jr.* *PU2LBD* *Por Aurélio Buarque de Hollanda, elite, do francês élite, significa “o que há de melhor em uma sociedade, minoria prestigiada, constituída pelos indivíduos mais aptos”. -- 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 beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
