I've not really had a lot of trouble getting my One Wire temperature sensor to function. But there have been lots of stumbles and I'm still confused in a lot of places. Let's start with what I'm running on a BBB RevB with the OS on a 16GB MicroSD card. uname -a for all shows: Linux beaglebone 4.1.4-ti-r8 #1 SMP PREEMPT Thu Aug 6 21:01:16 UTC 2015 armv7l GNU/Linux
I've configured w1.dts and used dtc to create the w1-00A0.dto which is in /lib/firmware Now here is where it starts to get complicated mostly because of the OS changes I believe. First of all I've got my DS1822 (1 wire with +/-2C resolution with 22- code) wired through a connector onto the SparkFun prototype cape. The EEROM on the cape is not yet programmed with anything so it's not in the list. A cat $SLOTS shows: 0: PF---- -1 1: PF---- -1 2: PF---- -1 3: PF---- -1 5: P-O-L- 0 Override Board Name,00A0,Override Manuf,w1 Notice that neither the HDMI nor the eMMC show up like they do on all the various examples on the web. I'm using the MicroSD card since the BBB has only 2GB. I'm operating headless with Ethernet and puTTY s there's nothing on the USB nor HDMI connector. Perhaps because nothing's using them? This is an example from https://github.com/cdsteinkuehler/beaglebone-universal-io/issues/21 $ cat /sys/devices/bone_capemgr.*/slots 0: 54:PF--- 1: 55:PF--- 2: 56:PF--- 3: 57:PF--- 4: ff:P-O-L Bone-LT-eMMC-2G,00A0,Texas Instrument,BB-BONE-EMMC-2G 5: ff:P-O-L Bone-Black-HDMI,00A0,Texas Instrument,BB-BONELT-HDMI And to get the One wire W1 virtual cape installed I've copied sudo sh -c "echo w1 > /sys/devices/platform/bone_capemgr/slots" Again, this is where it's interesting. After a restart this Debian Jesse image installs the https://github.com/cdsteinkuehler/beaglebone-universal-io cat $SLOTS 0: PF---- -1 1: PF---- -1 2: PF---- -1 3: PF---- -1 4: P-O-L- 0 Override Board Name,00A0,Override Manuf,cape-universaln To load the virtual One Wire I first have to remove the cape-universaln because it's already claimed the P8-11 pin I'm using for the DS1822. That's pretty easy once we know the virtual cape # sudo sh -c "echo '-4' > /sys/devices/platform/bone_capemgr/slots" One other thing that's different from the various forum examples is the location of the slots file. cat /sys/devices/bone_capemgr.*/slots The newer Debian image now adds 'platform' after devices and has trashed the .x after bone_capemgr. No more .7 or .9 And thenthe web documentation appears to get rather sparse. 1. I can't find where from the cape-universal.dtbo is loaded and which script puts it into the slots file. 2. There are several different copies of the cape-universaln.dts so which one is the correct one? 3. Is there a way to disable the pin used by the W1.dts so the SparkFun EEROM can be programmed with the information in the w1.dts file? Without recompiling the cape-univesal.dts file with the reference to the W1 pin removed? Here's where my system has the various .dts files. Which one is loaded? beaglebone- or bb.org-overlays? sudo find -name cape-universal* ./sys/firmware/devicetree/base/ocp/cape-universal ./opt/source/beaglebone-universal-io/cape-universal-00A0.dts ./opt/source/beaglebone-universal-io/cape-universala-00A0.dts ./opt/source/beaglebone-universal-io/cape-universaln-00A0.dts ./opt/source/bb.org-overlays/src/arm/cape-universal-00A0.dts ./opt/source/bb.org-overlays/src/arm/cape-universaln-00A0.dts ./lib/firmware/cape-universal-00A0.dtbo ./lib/firmware/cape-universaln-00A0.dtbo Thanks John -- 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. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/4207a6d7-dc44-4097-a91f-6bd1d0304bc8%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.