How do I use owfs to read an iButton temperature logger?

I've installed owfs and am trying to read the data off a iButton temperature logger.

owfs lets me mount the iButton as a fuse filesystem and I can see all the data. I'm having trouble figuring out what is the best way to access the data though. I can get individual readings by catting the files, e.g. cat onewire/{deviceid}/log/temperature.1, but the onewire/{deviceid}/log/temperature.ALL file is "broken" (possible too large, as histogram/temperature.ALL work fine).

A python script to read all files seems to work but takes a very long time. Is there a better way to do it? Does anyone have any examples?

I'm using Ubuntu 8.04 and couldn't get the java "one wire viewer" app to run.

Update: Using owpython (installed with owfs), I can get the current temperature but can't figure out how to get access to the recorded logs:

>>> import ow
>>> ow.init("u") # initialize USB
>>> ow.Sensor("/").sensorList()
[Sensor("/81.7FD921000000"), Sensor("/21.C4B912000000")]
>>> x = ow.Sensor("/21.C4B912000000")
>>> print x.type, x.temperature
DS1921           22

x.log gives an AttributeError.

From stackoverflow Tom

• I don't think there is a clever way. owpython doesn't support that telling from the API documentation. I guess /proc is your safest bet. Maybe have a look at the source of the owpython module and check if you can find out how it works.

  Tom : I wasn't able to find any documentation other than the docstrings. Is there anything else?
  From Armin Ronacher

• I've also had problems with owfs. I found it to be an overengineered solution to what is a simple problem. Now I'm using the DigiTemp code without a problem. I found it to be flexible and reliable. For instance, I store the room's temperature in a log file every minute by running

  /usr/local/bin/digitemp_DS9097U -c /usr/local/etc/digitemp.conf \
      -q -t0 -n0 -d60 -l/var/log/temperature
  

  To reach that point I downloaded the source file, untarred it and then did the following.

  # Compile the hardware-specific command
  make ds9097u
  # Initialize the configuration file
  ./digitemp_DS9097U -s/dev/ttyS0 -i
  # Run command to obtain temperature, and verify your setup
  ./digitemp_DS9097U -a 
  # Copy the configuration file to an accessible place
  cp .digitemprc /usr/local/etc/digitemp.conf
  

  I also hand-edited my configuration file to adjust it to my setup. This is how it ended-up.

  TTY /dev/ttyS0
  READ_TIME 1000
  LOG_TYPE 1
  LOG_FORMAT "%b %d %H:%M:%S Sensor %s C: %.2C F: %.2F"
  CNT_FORMAT "%b %d %H:%M:%S Sensor %s #%n %C"
  HUM_FORMAT "%b %d %H:%M:%S Sensor %s C: %.2C F: %.2F H: %h%%"
  SENSORS 1
  ROM 0 0x10 0xD3 0x5B 0x07 0x00 0x00 0x00 0x05
  

  In my case I also created a /etc/init.d/digitemp file and enabled it to run at startup.

  #! /bin/sh
  #
  # System startup script for the temperature monitoring daemon
  #
  ### BEGIN INIT INFO
  # Provides: digitemp
  # Required-Start:
  # Should-Start:
  # Required-Stop:
  # Should-Stop:
  # Default-Start:  2 3 5
  # Default-Stop:   0 1 6
  # Description:    Start the temperature monitoring daemon
  ### END INIT INFO
  
  DIGITEMP=/usr/local/bin/digitemp_DS9097U
  test -x $DIGITEMP || exit 5
  
  DIGITEMP_CONFIG=/root/digitemp.conf
  test -f $DIGITEMP_CONFIG || exit 6
  
  DIGITEMP_LOGFILE=/var/log/temperature
  
  # Source SuSE config
  . /etc/rc.status
  
  rc_reset
  case "$1" in
      start)
          echo -n "Starting temperature monitoring daemon"
          startproc $DIGITEMP -c $DIGITEMP_CONFIG  -q -t0 -n0 -d60 -l$DIGITEMP_LOGFILE
          rc_status -v
          ;;
      stop)
          echo -n "Shutting down temperature monitoring daemon"
          killproc -TERM $DIGITEMP
          rc_status -v
          ;;
      try-restart)
          $0 status >/dev/null && $0 restart
          rc_status
          ;;
      restart)
          $0 stop
          $0 start
          rc_status
          ;;
      force-reload)
          $0 try-restart
          rc_status
          ;;
      reload)
          $0 try-restart
          rc_status
          ;;
      status)
          echo -n "Checking for temperature monitoring service"
          checkproc $DIGITEMP
          rc_status -v
          ;;
      *)
          echo "Usage: $0 {start|stop|status|try-restart|restart|force-reload|reload}"
          exit 1
          ;;
  esac
  rc_exit
  

  Tom : Thanks for the info, but I don't think that helps getting access to the log stored on the DS1922T. I can read the current temperature using owpython or owfs, it's just accessing the stored measurements that I'm struggling with.
  From Diomidis Spinellis

• This is crazy complicated. Has anybody figured out a SIMPLE way to do this? I used to be able to get the onewire viewer to work in Windows, but I can't get it to work in Ubuntu. The OWFS just plain confounds me, and digitemp is no better. All that configuration for such a simple little device? I can interface with my mobile phone with less config than that!

  Any smart solutions out there?

  From mlissner

• Well I have just started to look at ibuttons and want to use python.

  This looks more promising:

  http://www.ohloh.net/p/pyonewire

  From Buteman