Superpatterns Pat Patterson on the Cloud, Identity and Single Malt Scotch

8Jun/1221

Raspberry Pi fix for HDMI to DVI cable issue

My Raspberry Pi arrived this week. After creating a boot image on an SD card I had lying around (using the excellent RasPiWrite utility), I initially booted it up on my TV, using the composite video output - all working!

Raspberry Pi in text mode

After a little exploration from the command line, startx brought up the GUI.

Raspberry Pi running X

As well as the composite video output, the Raspberry Pi supports HDMI. My monitor (a Viewsonic VX2235WM-3) has VGA and DVI inputs, so I ordered the AmazonBasics HDMI to DVI Cable. Connecting up to my monitor, I was disappointed to see no video signal whatsover - the monitor wasn't seeing the Raspberry Pi at all.

Googling around, I discovered that you can set various configuration options that are read before the Raspberry Pi even boots. With a little experimentation, I found that setting

hdmi_force_hotplug=1

in config.txt solves the problem - I see video output from the moment I power up the Raspberry Pi! This makes sense - the description of hdmi_force_hotplug is "Use HDMI mode even if no HDMI monitor is detected" - I'm guessing the cable is not signalling the presence of a monitor to the Raspberry Pi, so it decides that it doesn't need to send HDMI output.

Watch this space for more Raspberry Pi fun!

Comments (21) Trackbacks (1)
  1. I was hoping that this tip would sort out the issues I’ve been having with one of my monitors at home (as I’d somehow missed that option when scanning the list). Sadly not in my case. It seems that the Raspberry Pi is very fussy about DVI converters and DVI monitors (just like it is with SD cards).

  2. Sorry to hear that… Hopefully these issues will work themselves out and be fixed in firmware.

  3. Hi Pat, thanks for your tip, but it doesn’t work for me either…
    I agree with Chris, little pi is very fussy in terms of hardware.

  4. Actually, I went a bit further on my research and I found the following information:
    “Couple of small things to note: DVI can carry both analogue and digital video; your HDMI cable will only carry digital. So although most DVI-capable monitors support digital, I believe a very few are analogue only, and it may be worth checking to be sure. Secondly, HDMI carries both video and audio, but DVI is video only. You”ll therefore need to use the separate audio output from the RPi board.”

    Which would explain why some monitors stay dark, they’re not capable of running from digital signals.

    Source : http://www.frambozenbier.org/index.php/raspi-community-news/7877-theeponymousbob-on-hdmi-to-dvi-adapter-cable

  5. I have the same issue, my monitor only has DVI and DisplayPort, but RaspPi won’t even boot properly with the monitor connected via HDMI-DVI -adapter.

    Hard to say whether it’s an adapter, RaspPi or incompatibility problem. I know that my fairly recent 30″ supports digital signal, actually it explicitly doesn’t support analog at all. But it does require Dual-Link DVI cable, so maybe that’s the issue. More investigation needed…

  6. Dude. You just saved me a trip back to Fry’s to return this hdmi->dvi cable. Thanks!!!

  7. Glad to be of service, Ian!

  8. I sympathise with all those having RPi to monitor connection problems. I thought that connecting the RS Comp. supplied HDMI-HDMI cable through an HDMI-DVI convertor to the DVI slot on my Dell 1907FP monitor would be easy. The monitor displayed nothing except the “digital test card” flashing. I tried all solutions including adding a “home made” config file to the SD card with all possible combinations of set up. In the end I found a good web site – “www.pinout.ru” which shows the HDMI to DVI cable scheme connections in tabular form. With a circuit tester I found that the the HDMI pin to DVI pin contacts on my set up did not match what they should be. Today I received my “World of Data® – 3m HDMI to DVI Cable – Premium Quality / 1080p (Full HD) / v1.3 / Video / DVI-D (Dual Link) 24+1 Pins / 24k Gold Plated”
    from Amazon. Doing the circuit test again – all pins were as they should be! Raspberry Pi now fully working on my Dell monitor.
    Moral of the story – ensure that you get the right HDMI to DVI cable / adaptor!
    Regards, David.

  9. Worked for me. I also set config_hdmi_boost=4 to increase the signal.

    Thanks,

  10. Thanks Mike!
    config_hdmi_boost=4 worked for me.

  11. Hello Pat,

    I am not getting output in my Dell monitor, model number is ‘IN 2020M’.
    When I boot my monitor detects, but later goes to sleep mode, saying no DVI-D cable.

    the edidparser’s output is as follows

    Parsing edid.dat…
    HDMI:EDID version 1.3, 0 extensions, screen size 44×25 cm
    HDMI:EDID features – videodef 0×80 standby suspend active off; colour encoding:RGB444|YCbCr422; sRGB is not default colourspace; preferred format is native; does not support GTF
    HDMI:EDID found monitor S/N descriptor tag 0xff
    HDMI:EDID found monitor name descriptor tag 0xfc
    HDMI:EDID monitor name is DELL_IN2020M
    HDMI:EDID found monitor range descriptor tag 0xfd
    HDMI:EDID monitor range offsets: V min=0, V max=0, H min=0, H max=0
    HDMI:EDID monitor range: vertical is 50-76 Hz, horizontal is 30-83 kHz, max pixel clock is 170 MHz
    HDMI:EDID monitor range does not support GTF
    HDMI:EDID found unknown detail timing format: 1600x900p hfp:48 hs:32 hbp:80 vfp:3 vs:5 vbp:18 pixel clock:97 MHz
    HDMI:EDID established timing I/II bytes are A5 4B 00
    HDMI:EDID found DMT format: code 4, 640x480p @ 60 Hz in established timing I/II
    HDMI:EDID found DMT format: code 6, 640x480p @ 75 Hz in established timing I/II
    HDMI:EDID found DMT format: code 9, 800x600p @ 60 Hz in established timing I/II
    HDMI:EDID found DMT format: code 11, 800x600p @ 75 Hz in established timing I/II
    HDMI:EDID found DMT format: code 16, 1024x768p @ 60 Hz in established timing I/II
    HDMI:EDID found DMT format: code 18, 1024x768p @ 75 Hz in established timing I/II
    HDMI:EDID found DMT format: code 36, 1280x1024p @ 75 Hz in established timing I/II
    HDMI:EDID standard timings block x 8: 0x714F 8180 A9C0 0101 0101 0101 0101 0101
    HDMI:EDID found DMT format: code 21, 1152x864p @ 75 Hz (4:3) in standard timing 0
    HDMI:EDID found DMT format: code 35, 1280x1024p @ 60 Hz (5:4) in standard timing 1
    HDMI:EDID found DMT format: code 83, 1600x900p @ 60 Hz (16:9) in standard timing 2
    HDMI:EDID filtering formats with pixel clock > 162 MHz or h. blanking > 1023
    HDMI:EDID no known preferred format has been set
    HDMI:EDID filtering preferred group has been changed from Invalid to DMT
    HDMI:EDID best score mode initialised to DMT (4) 640x480p @ 60 Hz with pixel clock 25 MHz (score 18432)
    HDMI:EDID best score mode is now DMT (4) 640×480 @ 60 MHz with pixel clock 25 Hz (score 36864)
    HDMI:EDID best score mode is now DMT (6) 640×480 @ 75 MHz with pixel clock 31 Hz (score 46080)
    HDMI:EDID best score mode is now DMT (9) 800×600 @ 60 MHz with pixel clock 40 Hz (score 57600)
    HDMI:EDID best score mode is now DMT (11) 800×600 @ 75 MHz with pixel clock 49 Hz (score 72000)
    HDMI:EDID best score mode is now DMT (16) 1024×768 @ 60 MHz with pixel clock 65 Hz (score 94370)
    HDMI:EDID best score mode is now DMT (18) 1024×768 @ 75 MHz with pixel clock 78 Hz (score 117964)
    HDMI:EDID best score mode is now DMT (21) 1152×864 @ 75 MHz with pixel clock 108 Hz (score 174298)
    HDMI:EDID best score mode is now DMT (35) 1280×1024 @ 60 MHz with pixel clock 108 Hz (score 182286)
    HDMI:EDID best score mode is now DMT (36) 1280×1024 @ 75 MHz with pixel clock 135 Hz (score 196608)
    HDMI:EDID best score mode is now DMT (83) 1600×900 @ 60 MHz with pixel clock 108 Hz (score 197800)
    HDMI:EDID preferred mode is updated to DMT (83) 1600x900p @ 60 Hz with pixel clock 108000000 Hz
    HDMI:EDID has only DVI support and no audio support
    edid_parser exited with code 0

    my settings in config.txt
    hdmi_force_hotplug=1
    hdmi_group=2
    hdmi_mode=83
    hdmi_drive=1

    I also tried with only hdmi_force_hotplug=1 but no luck.

    Please help me out.

    Thank you.

  12. Hi Akshob – did you try config_hdmi_boost=4 ? that seems to work for some people.

  13. Thanks! This worked perfect for me and ended a bunch of frustration after having a cable shipped two day.

  14. Thank you!!! This worked for me. :)

  15. Yes, this is very helpful….thanks a lot man :)

  16. Thanks for the info on the HDMI>DVI adapter, I modified my file and it works great. Why this isn’t up on the official RPi site, IDK…

  17. Pat,

    What file do I edit to add the config_hdmi_boost=4 statement to?

    Thanks,
    John

  18. John – you edit config.txt in the boot partition. If you’ve booted the RPi from the SD card, this is at /boot/config.txt, or you can pop the SD card into a reader on your desktop/laptop and you should see config.txt right there.

  19. I went to Amazon and found the following part:

    HDMI Input to VGA Adapter Converter For PC Laptop NoteBook HD DVD by BestDealUSA

    and connected my Pi to an old VGA monitor laying around. Works great.

    Wunderbar !!! less than $5

  20. Thank you, It works fine for me.

    What I did with SSH :

    # mount /flash -o remount,rw
    # vi /flash/config.txt

    uncomment hdmi_force_hotplug=1

    Save the config
    # mount /flash -o remount,ro

    # reboot

    Thank’s

  21. hi everybody. I tried all of these options mentioned in this blog.
    What can i do further ?


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