Hi JrBenito - Looks like something went wrong with my schematic, I'm actually using a 4.7k resistor as described in the Maxim datasheet. However I tried with a 1k one but with the same result. Is there any way to see the RAW inputs/outputs on a pin?
Thanks! *Michael* On Saturday, September 6, 2014 5:25:03 PM UTC+2, JrBenito wrote: > > > 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 <vaesm...@gmail.com > <javascript:>> 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.
