Discussion

Force HDMI and DVI problems?

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mattrix  
Hi,

Is there a way to force only HDMI output?

Currently, if I don't boot up the Pi with an HDMI cable in, I think it's defaulting to composite out.

The raspberry Pi has a setting called "hdmi_force_hotplug=1" which forces to using HDMI even if cable not detected.

Also, with the Android image, I can't get it to display through a DVI adapter?

Any ideas?
mattrix  
Post Last Edited by mattrix at 2014-7-23 04:29

Post Last Edited by mattrix at 2014-7-23 04:29

Got it to not-autodetect (force HDMI) by changing the System configuration in DragonFace
  1. ;----------------------------------------------------------------------------------
  2. ;boot display configuration
  3. ;output_type  (0:none; 1:lcd; 2:tv; 3:hdmi; 4:vga)
  4. ;output_mode  (used for tv/hdmi output, 0:480i 1:576i 2:480p 3:576p 4:720p50 5:720p60 6:1080i50 7:1080i60 8:1080p24 9:1080p50 10:1080p60 11:pal 14:ntsc)
  5. ;output_mode  (used for vga output, 0:1680*1050 1:1440*900 2:1360*768 3:1280*1024 4:1024*768 5:800*600 6:640*480 10:1920*1080 11:1280*720)
  6. ;auto_hpd     (auto detect hdmi/cvbs/ypbpr plug in)
  7. ;----------------------------------------------------------------------------------
  8. [boot_disp]
  9. output_type              = 3
  10. output_mode              = 5
  11. auto_hpd                 = 1
Copy the Code
change auto_hpd to a 0

dlanor  
Thanks for the tip. I've saved it to a text file for reference (like I have with your other DragonFace advice).

I suppose the "hpd" acronym would stand for "Hdmi Port Detection"... ?

Btw: I haven't really looked into it yet, but exactly how is the VGA signal output ?
I wouldn't use that myself, but a friend of mine is considering using the BPi with a PC monitor having no HDMI.

I know there are separate output ports for LCD and composite TV, but I'm not aware of any VGA port. So I'm wondering if that signal really has a separate port using some I/O pin header, or if it's intended for use by connecting some adapter to the HDMI port.

Best regards: dlanor

mattrix  
yeh.

I don't know what the VGA output is for..
I know the Banana Pi image is a near exact copy of the CubieBoard2 image (I have a CB2 as well).
But, that doesn't have VGA output either.

There are a lot of settings in that file in DragonFace.
I have disabled a lot of things I don't need (GPIO, etc)
Also, things like NAND boot were still enabled (from CB2).

Next I'm moving onto the boot init scripts to disable any services I don't need.

I'm creating a device that only has to run 1x app on boot, so want it quick as possible

NiFu  
Also, with the Android image, I can't get it to display through a DVI adapter?

I also have no luck (Android-, Lubuntu- and Raspbian-Image). I have tested 2 DVI monitors and 3 HDMI-to-DVI adapters. At the beginning the monitor LED is yellow (stand by). After starting BPi the monitor LED switched to green - but no picture. I also bought a HDMI-DVI cable because I thought the signal is not strong enough whilst using the HDMI-to-DVI adapters. But no luck.

What I have recognized: When I switch off the monitor and switch on I see sometimes for 1 second the screen.

mattrix  
Yeh.

Maybe Tony can help us out with the DVI problem?

Reply 6# mattrix

I do use one DVI monitor, it works. But another two failed. I will try to find out the problem.  

BartDG  
I'll watch this tread from very closely since this interests me as well.  I want to use the BPi for controlling a touch screen with my home automation.  
I tried this before with a Raspberry Pi, but it was not fast enough.  I also tried an Odroid U3, which was plenty fast, but with that device, it seemed impossible to convert the HDMI signal to DVI.  In the end, after 3 adapters, I got it to work in Linux, but not for Android.  I'd prefer to use android because my home automation system has got an Android App available and hence I would not have to alter Linux to fit my needs.  Unfortunately, two problems: in Android, the screen remained green and everything was very slow.  Second, in Linux, my touch screen was recognised and I could use it.  In Android it was not.  But I'm guessing that's just a matter of configuring? (I mean, if Android doesn't work with touch screens???)

Now I've got two options left: the Banana Pi and the Cubieboard 3 (Cubietruck).  The Banana Pi is cheaper, but the Cubietruck features a VGA output as well, which I can also use with my touch screen.   BTW Dlanor: the Banana Pi and the Cubietruck use the same Allwinner A20 chip, which is probably why there are references to VGA in the BPi config files, even though it doesn't feature one.

If all else fails, I guess the last resort will be to simply buy a mini-ITX Atom board, and run it like that.  But that solution would no doubt be more expensive and consume more power.  I'd also have a harder time finding a wall-mountable mini-ITX case.  Which is why I still would prefer a solution à la BPi.

NiFu  
See this comment for "HDMI to VGA adapter".

mugs500  
Reply 2# mattrix


When I open the image with dragonface i get an error saying the firmware is not supported. And when I try to burn my modified image with phoenixcard it crashes. Have any of you been able to overcome this  ?

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