My problem with 12-bit reads degenerating to half-degree steps seems to be hiding since I built a new system with Ubuntu 14.04. I've only seen a few individual readings that looked "stuck" at the previous value since then, never full days of half-degree steps. But I still get two kinds of rare, occasional errors. There are the expected 85C errors, and these: --- Thu Jul 03 2014 22:15:01 GMT-0700 (PDT) cd 01 4b 46 7f ff 03 10 4a : crc=4a YES cd 01 4b 46 7f ff 03 10 4a t=28812 Thu Jul 03 2014 22:20:02 GMT-0700 (PDT) ff ff ff ff ff ff ff ff ff : crc=c9 NO cd 01 4b 46 7f ff 03 10 4a t=-62 Thu Jul 03 2014 22:25:02 GMT-0700 (PDT) c9 01 4b 46 7f ff 07 10 64 : crc=64 YES c9 01 4b 46 7f ff 07 10 64 t=28562 --- Fri Jul 04 2014 13:55:01 GMT-0700 (PDT) c8 01 4b 46 7f ff 08 10 3f : crc=3f YES c8 01 4b 46 7f ff 08 10 3f t=28500 Fri Jul 04 2014 14:00:02 GMT-0700 (PDT) ff ff ff ff ff ff ff ff ff : crc=c9 NO c8 01 4b 46 7f ff 08 10 3f t=-62 Fri Jul 04 2014 14:05:02 GMT-0700 (PDT) cc 01 4b 46 7f ff 04 10 67 : crc=67 YES cc 01 4b 46 7f ff 04 10 67 t=28750 ---
I've never seen -62 errors before. All of them I've captured in detail match the above pattern, where the first byte string is all 'ff', and the second byte string matches the previous valid temperature exactly. What could be happening there? If the "t=" value is being derived from the byte string to the left of it, it should be the correct temperature. But it is always -62. Why are there two lines of bytes? Are they separate reads? Apparently there are supposed to be "statistics" somewhere, but I don't seem to have any. Here is all I find: --- ubuntu@arm:/sys/devices/w1_bus_master1$ ls 28-0000008847d6 power w1_master_add w1_master_name w1_master_remove w1_master_slaves 28-000000884d88 subsystem w1_master_attempts w1_master_pointer w1_master_search w1_master_timeout driver uevent w1_master_max_slave_count w1_master_pullup w1_master_slave_count --- Maybe the w1 interface doesn't provide statistics? Am I missing some source of deeper documentation than the web site provides? Loren | Loren Amelang | lo...@pacific.net | ------------------------------------------------------------------------------ Open source business process management suite built on Java and Eclipse Turn processes into business applications with Bonita BPM Community Edition Quickly connect people, data, and systems into organized workflows Winner of BOSSIE, CODIE, OW2 and Gartner awards http://p.sf.net/sfu/Bonitasoft _______________________________________________ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
