Trouble

Can't get display to work

7 1791
Edited by cjbathras at Dec 21, 2015 23:16

Hi,

I just got my Lemaker Guitar and got it up and running.  The problem I'm having is that the HDMI display does not work.  I get an image, but it's jumbled.  I've tried it on two different monitors with different HDMI cables and get the same result.  Here's what it looks like:

IMG_0770.jpg

Any idea what could be going wrong?  Maybe a bad HDMI connection?  I can connect it to my LAN and SSH into it so I know it's up and running properly.

Thanks!

UPDATE: A friend of mine is having the same issue, so it's not just my board.  Frustrating.
rogier  
Edited by rogier at Dec 22, 2015 03:49

I had the same problem.
It does work when you wait to connect HDMI until it has booted, but that is not a solution.

What really helped was flashing the eMMC with the most recent Android (v1511) version.
It seems that even when you boot from SD, it still starts from the eMMC first.

(maybe u-boot was still loaded from eMMC with incompatible settings, judging a bit from:
http://forum.lemaker.org/forum.p ... 515&page=2#pid90541
this should be solved from v1511, but I am only guessing this is the same problem)

So it is not the guitar, not the baseboard, nor the HDMI cable and resetting doesn't help, updating the eMMC Android to v1511 did.
Afterwards I was also able to flash recent Linux versions to the eMMC without HDMI problems.

rogier replied at Dec 22, 2015 03:45
I had the same problem.
It does work when you wait to connect HDMI until it has booted, but that is ...

Rogier,

Thanks so much.  Waiting to plug in the HDMI until after the Guitar booted worked.  Not ideal, but that gets me going.  I'll work on flashing the eMMC next.

Curt

rogier  
Just as note: For updating the eMMC flash, you don't need a special USB 3.0 cable, you can use a standard USB 2.0 micro cable (the one you can use to connect your phone to a PC/Laptop) and put it in the left side of the USB 3.0 connector.

rogier replied at Dec 23, 2015 08:14
Just as note: For updating the eMMC flash, you don't need a special USB 3.0 cable, you can use a sta ...

Any idea how to flash the eMMC using a Mac?  I don't have a PC.  All the documentation and tools I've seen show how to do it using a PC or Linux.

rogier  
Edited by rogier at Dec 23, 2015 15:40

What could work is using the instructions provided here:
http://wiki.lemaker.org/LeMaker_ ... x_platform_firmware
It is a way to flash the Guitar from a shell on the Guitar itself. I think the bootloader (and possibly uboot) needs to be updated, so a SD card boot boots fully from the SD card and not half from the eMMC flash. (So I don't think it is needed to install Android v1511, just get the bootloader to v1511).



Another option is running Linux on your Mac using VirtualBox.
https://www.virtualbox.org/wiki/Downloads (http://download.virtualbox.org/v ... 0.12-104815-OSX.dmg)
I recommend Ubuntu 14.04 LTS for this: http://releases.ubuntu.com/14.04/, just because it's the most common.
If you don't want/need a Linux GUI, take the server amd64 version
(http://releases.ubuntu.com/14.04/ubuntu-14.04.3-server-amd64.iso),
otherwise the desktop amd64 version
(http://releases.ubuntu.com/14.04/ubuntu-14.04.3-desktop-amd64.iso)

And follow the instructions here from paragrah 2.4 (note there is a missing underscore in the tar command)
http://mirror.lemaker.org/LeMaker%20Guitar%20User%20Manual%20(The%20first%20edition).pdf




If you have any questions, don't hestitate to ask.

I am having same HDMI scrambled issue as well with the 1601 image.... my guitar eMMC came preloaded with some version of Android. I have tried all HDMI modes in Android to set HDMI mode of my screen. I will try the HDMI unplug/plug hack next.

Well that's good. I can see Desktop now...now for sys-config

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