Temperature of X display

[vovchik]

Dear all,

Here is a BaCon port I just did of a useful c program by Fabian Foerg (c source is included and BaCon source has link to original GitHub page) that sets the screen temperature for X displays. It is easier to use than redshift and f.lux. Have fun. I hope it works for you.

With kind regards,
vovchik

@ Alex: I just tried it on my RPI and it seems to have no effect (it compiles normally). Do you have any idea or fix?

Attachments:

coltemp-src.tar.gz (3.09 KB)

[Pjot]

Thanks vovchik!

All works for me. The code looks very good btw, it is a very nice example of mixing BaCon syntax with C.

Best regards
Peter

[alexfish]

Hi Vovchik

Looking at it now . did some work back on pi 2 .
not sure if will get it working, but will try

as to get the Arm cpu bits , 'temperature' there is Raspberry call for this one

vcgencmd measure_temp

in a generallised way could have these in the start up

check if arm and which os
uname -a
and check if have display and what number is it
getenv("DISPLAY");



BR
Alex

nothing so far

only thing I can recall

in the glx demo's .. noticed that gamma was not available on rpi . not sure if this is connected with the above

a direct poke reveals

xrandr -d :0 --output default
xrandr: Failed to get size of gamma for output default

[alexfish]

Hi Vovchik

now looking in the tvservice

IE
$ tvservice -h
Usage: tvservice [OPTION]...
 -p, --preferred                   Power on HDMI with preferred settings
 -e, --explicit="GROUP MODE DRIVE" Power on HDMI with explicit GROUP (CEA, DMT, CEA_3D_SBS, CEA_3D_TB, CEA_3D_FP, CEA_3D_FS)
                                     MODE (see --modes) and DRIVE (HDMI, DVI)
 -t, --ntsc                        Use NTSC frequency for HDMI mode (e.g. 59.94Hz rather than 60Hz)
 -c, --sdtvon="MODE ASPECT"        Power on SDTV with MODE (PAL or NTSC) and ASPECT (4:3 14:9 or 16:9)
 -o, --off                         Power off the display
 -m, --modes=GROUP                 Get supported modes for GROUP (CEA, DMT)
 -M, --monitor                     Monitor HDMI events
 -s, --status                      Get HDMI status
 -a, --audio                       Get supported audio information
 -d, --dumpedid <filename>         Dump EDID information to file
 -j, --json                        Use JSON format for --modes output
 -n, --name                        Print the device ID from EDID
 -h, --help                        Print this information
pi@raspberrypi:~ $ tvservice -s
state 0x120006 [DVI CEA (31) RGB lim 16:9], 1920x1080 @ 50.00Hz, progressive
pi@raspberrypi:~ $

Alex

[vovchik]

Dear Alex,

I think you are on the right track with RPI. I also get:

xrandr -d :0 --output default
xrandr: Failed to get size of gamma for output default

So we have to see how display gamma is controlled/managed. Have to do some reading...

With thanks and kind regards,
vovchik

[alexfish]

Hi Vovchik

the GAMMA Ramp is not in the list of groups

an the the returned value of pixels = 1 the

PRINT res->ncrtc . so nothing can be done there

ADDED

whilst on with using dispman as posted on the RPI 3 "Hardware windows EGL " thread now taking a closer look at it's API
note how bright and crisp these bits are

May Expose something , May be not , If can find it
Then will post further

BR
Alex

[alexfish]

Hi Vovchik

As mention in PM most of the finer details are in the VC including the headers for raspi commands as posted above

I put a copy in the home folder//

the bits are hard to find .. through the we need to look at are in the
/home/pi/vc/include/interface/vmcs_host

and first bit I am looking at is the 'vc_dispmanx.h'
BR
Alex

[vovchik]

Dear Alex,

From what I just read, I gather that RPI's X server is pretty much a simple wrapper around a "dumb" frame buffer not really communicating much with the GPU. There might be a way to fix up X11 and will look into that now...

With kind regards,
vovchik

[alexfish]

Hi Vovchik

I tried latest messa glx testing a while ago . got a no show there , not sure what the latest messa will do or have they put that bit in

for poking around in the x as in the root

I go in using 0 .. 0x0


   Display *display = XOpenDisplay(0x0);
   Screen * screen ;
   int default_screen = DefaultScreen(display);

Then
XQuery****

BR
Alex

[alexfish]

Hi Vovchik

thought would put cairo dock in , to see if gamma works there

No Gamma there..

BR
Alex

[vovchik]

Dear Alex,

That means that it is somewhat difficult to get at the backlighting and individual pixel brightness at the level of hardware - I am certain it can be done, but we are missing some tiny bit of info somewhere, and X11 is crippled (or limping) in that respect. More reading...

With kind regards,
vovchik

[alexfish]

Hi Vovchik

have done some reading.

esp a display for the RPI there is an official one ,

in short , it looks like some of the hdmi bits are used by the gpio pins , I think says he. in one some up not sure

but will have to look at the RPI blogs ref display for RPI, on it is an api for the back light etc
and can be called from the cmd line ,, think have found some bits in the vc api that related to this ,, if can find them . then will post via PM

so I be getting off this one for now.

good news on the dismanx side on the RPI thread , re the two windows and getting them to raise and lower

it be just a call to update the dismanx , and the window U be on raises to the top.. what a find

BR
Alex

[vovchik]

Dear Alex,

Funny how weird xrandr behaviour in RPI - and subsequent reading - may have given you insights into dismanx. I often get sidetracked and find out useful things I would not have discovered otherwise:)

With kind regards,
vovchik

[alexfish]

Hi Vovchik

'find out useful things'

in at least found the bit to control the two bits i be working on , if it had not been for this thread . could have taken longer
for me now ,they look like very "Nice" bits
Thanks
+
BR
Alex

[alexfish]

Hi Vovchik

possible not the place to post yet

Esp For U & what vector graphics can do without svg or cairo on The RPI

follow this link
github.com/ajstarks/openvg

BR
Alex