maemo.org - Talk - How to distinguish camera cover opening from closing via dbus?

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- - How to distinguish camera cover opening from closing via dbus? (https://talk.maemo.org/showthread.php?t=76944)

How to distinguish camera cover opening from closing via dbus?

I've been trying to figure this out for a while now.
Yes, I've searched... for a while now. Googling "+(maemo OR n900) +dbus open close +(camera OR lense) +(cover or shutter)" doesn't return anything useful.

The problem is, according to "dbus-monitor --system", the same two signals are sent whether the camera cover is opening or closing.

Shutter opening:

Code:

signal sender=:1.13 -> dest=(null destination) serial=9631 path=/org/freedesktop/Hal/devices/platform_cam_shutter; interface=org.freedesktop.Hal.Device; member=PropertyModified

   int32 1

   array [

      struct {

         string "button.state.value"

         boolean false

         boolean false

      }

   ]

signal sender=:1.13 -> dest=(null destination) serial=9632 path=/org/freedesktop/Hal/devices/platform_cam_shutter; interface=org.freedesktop.Hal.Device; member=Condition

   string "ButtonPressed"

   string "cover"

Shutter closing:

Code:

signal sender=:1.13 -> dest=(null destination) serial=9636 path=/org/freedesktop/Hal/devices/platform_cam_shutter; interface=org.freedesktop.Hal.Device; member=PropertyModified

   int32 1

   array [

      struct {

         string "button.state.value"

         boolean false

         boolean false

      }

   ]

signal sender=:1.13 -> dest=(null destination) serial=9637 path=/org/freedesktop/Hal/devices/platform_cam_shutter; interface=org.freedesktop.Hal.Device; member=Condition

   string "ButtonPressed"

   string "cover"

This makes no sense to me at all.
One thing I noticed is dmesg does show the difference:

Code:

Nokia-N900:~# dmesg| grep shutter| tail -2 

[13739.665222] cam_shutter (GPIO 110) is now open

[13741.516632] cam_shutter (GPIO 110) is now closed

Unfortunately, that's not useful for triggering without being really kludgey.

Does anyone know what line I can use with dbus-scripts to distinguish camera cover opening from closing?

Re: How to distinguish camera cover opening from closing via dbus?

Maybe HAL is being slow. When opening the shutter, maybe you could wait a little bit longer and see if you get a similar line saying true for "button.state.value"

Alternatively, you might be able to just add a blanket watch for the "shutter opened" condition but then run "lshal -s -u /org/freedesktop/Hal/devices/platform_cam_shutter | grep button.state.value | awk '{print $3}'" in the script you plan have DBus-Scripts execute - if that command correctly returns the state of the shutter, you can just have if conditions that do whatever depending on if it returns "false" or "true"

Re: How to distinguish camera cover opening from closing via dbus?

I left dbus-monitor running well after the camera app fired up, and all I saw was phone-status changes (signal strength, etc.).

I like your suggestion... that's a lot cleaner than "dmesg | grep shutter | tail -1 | awk '{print $NF}'". :)

Thanks!

Re: How to distinguish camera cover opening from closing via dbus?

Actually, sorry, but after looking at the lshal man page again, I saw a command called hal-get-property.

hal-get-property --udi /org/freedesktop/Hal/devices/platform_cam_shutter --key button.state.value is cleaner than the lshal solution above

Re: How to distinguish camera cover opening from closing via dbus?

Ugh! I thought we had a winner here, but unfortunately, simply unlocking or locking the screen fires off the same dbus events (twice!) as opening or closing the camera cover! :(

Code:

=================================

Arg 1: :1.13

Arg 2: null

Arg 3: org.freedesktop.Hal.Device

Arg 4: PropertyModified

=================================

Arg 1: :1.13

Arg 2: null

Arg 3: org.freedesktop.Hal.Device

Arg 4: Condition

Arg 5: ButtonPressed

Arg 6: cover

=================================

I guess I should elaborate a bit on what I'm trying to do here.
I've set my N900 up to overclock (only 750) when I unlock the screen, then drop back to the default profile when I lock the screen (I plan to drop to a low voltage/slow profile after I get the rest finished).
This part works wonderfully with the following triggers:

Code:

/usr/local/bin/screenunlocked * * com.nokia.mce.signal tklock_mode_ind unlocked

/usr/local/bin/screenlocked * * com.nokia.mce.signal tklock_mode_ind locked

Unfortunately, my N900, though quite stable when overclocked with the voltage profile I'm using, will crash or lock up if I try and record video with those settings (obviously my DSP isn't as tolerant as my CPU). So, I want to have it drop down to the default profile when the camera door is open, but clock back up when the camera door closes again.

My current dbus-scripts setting for the camera trigger is:

Code:

/usr/local/bin/camerashutter * * org.freedesktop.Hal.Device Condition ButtonPressed cover

I decided to log each time each of the scripts were called and noticed this every time I unlocked the screen:

Code:

camerashutter called

screenunlocked called

camerashutter called

Similarly, every time I locked the screen:

Code:

camerashutter called

screenlocked called

camerashutter called

If I simply opened or closed the camera door, the expected happened:

Code:

camerashutter

I guess I still need a signal that can be reliably tied to the camera cover.
Any ideas?