[Buildroot] setting up directfb for a raspberry pi + waveshare32b display

Lou Crittenden loucrittenden63 at gmail.com
Thu Feb 19 20:02:25 UTC 2015


>Hi Lou,
>Do you want to use qt quick with directfb?
>I have waveshare 4 inch (A), and for now without any success on this.
>Everything with OGL is rendered on HDMI output,
>so I think it's not possible to use fbdev with qt quick. Code with widgets
works >good.
>I you will have any success on this, I would be greatful for any info.
>Regards
>Zygmunt

Qt quick looks promising to use as an interface for directfb, although I
never have gotten into it. You mentioning it to me is the first time I have
heard of it. I watched a demo on how to create an interface here
https://www.youtube.com/watch?v=_6_F6Kpjd-Q. By the looks of what I saw in
the vid, it looks promising, but of course that guy made it look easy.

Do you know what framebuffer you are outputting to? Mine is /dev/fb1.
/dev/fb0 is the hdmi/video out, assuming you are using a raspberry pi.

On Thu, Feb 19, 2015 at 7:27 AM, Zygmunt Ptak <zygmuntptak at gmail.com> wrote:

> Hi Lou,
> Do you want to use qt quick with directfb?
> I have waveshare 4 inch (A), and for now without any success on this.
> Everything with OGL is rendered on HDMI output,
> so I think it's not possible to use fbdev with  qt quick. Code with
> widgets works good.
> I you will have any success on this, I would be greatful for any info.
> Regards
> Zygmunt
>
> 2015-02-19 14:14 GMT+01:00 Lou Crittenden <loucrittenden63 at gmail.com>:
>
>> >I was thinking I could make an ads7846 configuration file at
>> >/etc/modprobe.d>>/00-ads7846.
>> >conf (like we did with the waveshare32b) to also include the ads7846
>> >touchscreen device with reversed axes.
>>
>> >For starters, the contents will be:
>>
>> >options ads7846_device debug=1 cs=1 speed=2000000 model=7846 >x_min=230
>> x_max=3900 y_min=200 y_max=3700 x_plate_ohms=80 >pressure_max=255
>> gpio_pendown=23 keep_vref_on=1
>>
>> >I will see how this goes and edit accordingly.
>>
>> Disregard that!! I remember now making the /etc/init.d/s30fbtft script
>> and I found the part that has the "swap_xy=0" and am changing it to
>> "swap_xy=1", and doing the tweaks from there.
>>
>> On Wed, Feb 18, 2015 at 7:10 PM, Lou Crittenden <
>> loucrittenden63 at gmail.com> wrote:
>>
>>> I can also confirm that the axes are reversed on the df_bltload by
>>> running: df_bltload --dfb:fbdev=/dev/fb1.
>>>
>>> I was thinking I could make an ads7846 configuration file at
>>> /etc/modprobe.d/00-ads7846.conf (like we did with the waveshare32b) to also
>>> include the ads7846 touchscreen device with reversed axes.
>>>
>>> For starters, the contents will be:
>>>
>>> options ads7846_device debug=1 cs=1 speed=2000000 model=7846 x_min=230
>>> x_max=3900 y_min=200 y_max=3700 x_plate_ohms=80 pressure_max=255
>>> gpio_pendown=23 keep_vref_on=1
>>>
>>> I will see how this goes and edit accordingly.
>>>
>>> On Wed, Feb 18, 2015 at 6:13 PM, Lou Crittenden <
>>> loucrittenden63 at gmail.com> wrote:
>>>
>>>> on the df_knuckles demo, the touch screen works, but it appears that I
>>>> have reverse the axes somehow, as it appears that if I move my finger left
>>>> to right, the skull moves up and down and vice versa.
>>>>
>>>> On Wed, Feb 18, 2015 at 4:29 PM, Lou Crittenden <
>>>> loucrittenden63 at gmail.com> wrote:
>>>>
>>>>> Got it to work after about a 2 hour rebuild with make clean all and
>>>>> removing the said option. You guessed properly. I also had to use fb1
>>>>> instead of fb0. I would love to use fb1 as the default framebuffer.
>>>>>
>>>>> On Wed, Feb 18, 2015 at 11:30 AM, Peter Seiderer <ps.report at gmx.net>
>>>>> wrote:
>>>>>
>>>>>> Hello Lou,
>>>>>>
>>>>>> On Tue, Feb 17, 2015 at 07:21:36PM -0600, Lou Crittenden wrote:
>>>>>> > I tried running them and got an error stating it can't find
>>>>>> /dev/fusion0 or
>>>>>> > /dev/fusion/0 after running any of the df_knuckles --dfb commands
>>>>>> with the
>>>>>> > exception of the help command.
>>>>>> >
>>>>>> > Did you have to create new device nodes and directories? I had to
>>>>>> using
>>>>>> > mkdir /dev/fusion
>>>>>> > mkdir /dev/fusion0
>>>>>> >
>>>>>> > then made the device nodes with these commands:
>>>>>> >
>>>>>> > mknod /dev/fusion/0 c 253 0
>>>>>> > mknod /dev/fusion/0 c 252 0
>>>>>> > mknod /dev/fusion0 c 252 0
>>>>>> > mknod /dev/fusion0 c 253 0
>>>>>> >
>>>>>> > I then ran
>>>>>> > $ df_knuckles --dfb:fbdev=/dev/fb1
>>>>>> > $ df_dok --dfb:fbdev=/dev/fb1
>>>>>> > $ df_cpuload --dfb:fbdev=/dev/fb1
>>>>>> >
>>>>>> > both as root and as another user and I get:
>>>>>> > (!) Fusion/Init: could not enter world 0! not a typewriter
>>>>>> >
>>>>>> > I have no idea what that means. Other people have gotten the error
>>>>>> as well,
>>>>>> > but haven't had solutions, as per various searches.
>>>>>> >
>>>>>>
>>>>>> From package/directfb/directfb.mk:
>>>>>>
>>>>>> ...
>>>>>> ifeq ($(BR2_PACKAGE_DIRECTFB_MULTI),y)
>>>>>> DIRECTFB_CONF_OPTS += --enable-multi --enable-fusion
>>>>>> DIRECTFB_DEPENDENCIES += linux-fusion
>>>>>> endif
>>>>>> ...
>>>>>>
>>>>>> Disable DIRECTFB_MULTI, rebuild directfb and try again (just a guess,
>>>>>> not tested)...
>>>>>>
>>>>>> Regards,
>>>>>> Peter
>>>>>>
>>>>>> > On Tue, Feb 17, 2015 at 4:38 PM, Peter Seiderer <ps.report at gmx.net>
>>>>>> wrote:
>>>>>> >
>>>>>> > > Hello Lou,
>>>>>> > >
>>>>>> > > On Thu, Feb 12, 2015 at 05:35:32PM -0600, Lou Crittenden wrote:
>>>>>> > > > Hi all. I have a buildroot setup running on a raspberry pi
>>>>>> model b+ and a
>>>>>> > > > waveshare32b 3.2" display and was able to get the system to
>>>>>> work with the
>>>>>> > > > display thanks to peter seiderer's awesome patch that builds
>>>>>> the fbtft
>>>>>> > > > drivers for buildroot, but I now would like to set up directfb
>>>>>> to work on
>>>>>> > > > this setup. Directfb built nicely, along with sdl and qt5 (I'm
>>>>>> setting up
>>>>>> > > > the framework for a gui on a buildroot based media player), but
>>>>>> I cannot
>>>>>> > > > get anything to work on directfb. I run the command
>>>>>> "df_drivertest" that
>>>>>> > > > tests for the driver, and it gives a
>>>>>> > > >
>>>>>> > > > (#) DirectFBError [dfb->CreateSurface( dfb, &dsc, &primary )]:
>>>>>> The
>>>>>> > > > requested operation or an argument is (currently)Not
>>>>>> > > > supported.
>>>>>> > > >
>>>>>> > > > The same thing happens when I try to run any of their directfb
>>>>>> demos.
>>>>>> > > > I went on their site, directfb.org, and a lot of the links
>>>>>> that would
>>>>>> > > > help are dead
>>>>>> > > >
>>>>>> > >
>>>>>> > > Just a quick test:
>>>>>> > >
>>>>>> > > $ df_knuckles --dfb:help
>>>>>> > > $ df_knuckles --dfb:fbdev=/dev/fb1
>>>>>> > > $ df_dok --dfb:fbdev=/dev/fb1
>>>>>> > > $ df_cpuload --dfb:fbdev=/dev/fb1
>>>>>> > >
>>>>>> > > work for me...
>>>>>> > >
>>>>>> > > $ df_drivertest  --dfb:fbdev=/dev/fb1
>>>>>> > > df_drivertest.c <97>:
>>>>>> > >         (#) DirectFBError [dfb->CreateSurface( dfb, &dsc,
>>>>>> &primary )]: The
>>>>>> > > requested operation or an argument is (currently) not supported
>>>>>> > >
>>>>>> > > failes..
>>>>>> > >
>>>>>> > > Regards,
>>>>>> > > Peter
>>>>>> > >
>>>>>> > > >
>>>>>> > > > I want to use a setup lighter than xorg and supports
>>>>>> touchscreen for a
>>>>>> > > > gui on a multimedia player I am working on.
>>>>>> > >
>>>>>>
>>>>>
>>>>>
>>>>
>>>
>>
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>
>
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