tvservice -s is giving wrong resolution

[hawkerpl]

Hi, i have problem with detecting resolution of plugged in monitor (i am trying to detect whether monitor is plugged at all to use it in my app in python), i have tried

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tvservice -s

which is giving me wrong answers:
when hdmi is unplugged at booting:

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state 0x120016 [DVI DMT (4) RGB full 4:3], 640x480 @ 60.00Hz, progressive

when hdmi is plugged after that:

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state 0x120016 [DVI DMT (4) RGB full 4:3], 640x480 @ 60.00Hz, progressive

(i was expecting some information about hdmi not being plugged)

when hdmi is plugged at booting:

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state 0x120016 [DVI DMT (58) RGB full 16:10], 1680x1050 @ 60.00Hz, progressive

when hdmi is unplugged after that

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state 0x120016 [DVI DMT (58) RGB full 16:10], 1680x1050 @ 60.00Hz, progressive

my main goal is to check whether hdmi monitor is plugged

[jamesh]

If nothing is detected on the HDMI port at boot, it defaults to VGA. So that matches what you are seeing.

Can you not just extract the resolution from tvservice using awk or similar? And if it 640x480, assume it's not connected?

[dom]

@hawkerpi
I'm guessing you have added hdmi_force_hotplug=1 (or booting without hdmi plugged in would have defaulted to composite).

You'll have to remove that if you want to detect the real hotplug value.

With that removed the "state 0x120016" will change when hdmi cable is removed.

[hawkerpl]

@dom yes, it was set to 1 but if i tried to change it to 0 or delte that setting from config, nothing changed.
What is more "tvservice -M" is not detecting whether i am pluging or unplugging hdmi.
My config.txt:

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# uncomment if you get no picture on HDMI for a default "safe" mode
#hdmi_safe=1

# uncomment this if your display has a black border of unused pixels visible
# and your display can output without overscan
#disable_overscan=1

# uncomment the following to adjust overscan. Use positive numbers if console
# goes off screen, and negative if there is too much border
#overscan_left=16
#overscan_right=16
#overscan_top=16
#overscan_bottom=16

# uncomment to force a console size. By default it will be display's size minus
# overscan.
#framebuffer_width=1280
#framebuffer_height=720

# uncomment if hdmi display is not detected and composite is being output
#hdmi_force_hotplug=1

# uncomment to force a specific HDMI mode (this will force VGA)
#hdmi_group=1
#hdmi_mode=1

# uncomment to force a HDMI mode rather than DVI. This can make audio work in
# DMT (computer monitor) modes
#hdmi_drive=2

# uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display
#config_hdmi_boost=4

# uncomment for composite PAL
#sdtv_mode=2

#uncomment to overclock the arm. 700 MHz is the default.
#arm_freq=800

# for more options see http://elinux.org/RPi_config.txt

# NOOBS Auto-generated Settings:
hdmi_force_hotplug=1
config_hdmi_boost=4
overscan_left=24
overscan_right=24
overscan_top=16
overscan_bottom=16
disable_overscan=0

@jamesh
I'd do that in the end, but i rather wanted to detect whether it is unplugged during running time, not only at boot.

[dom]

@dom yes, it was set to 1 but if i tried to change it to 0 or delte that setting from config, nothing changed.
What is more "tvservice -M" is not detecting whether i am pluging or unplugging hdmi.
My config.txt:

Note that config listed is the NOOBS config, not the raspbian config.
Edit the config from within raspbian using "sudo nano /boot/config.txt", or using the NOOBS config.txt editor.

[hawkerpl]

@dom
as i said before, i did that and nothing has changed

[AndrewS]

@hawkerpi Looks like you've commented out the first occurrence of hdmi_force_hotplug but there's actually a second occurrence of this setting near the bottom of your config.txt which hasn't been commented out.

@dom By default NOOBS doesn't have a config.txt, but it does pre-configure the config.txt of the OSes it installs to set them up to the same display-mode that NOOBS was running in. That's what the "# NOOBS Auto-generated Settings" is about - this behaviour will probably be changing in a future version of NOOBS.

[hawkerpl]

@AndrewS thanks, that worked