Connecting 1366 x 768 to dragonboard410c VGA cable

96boards

#1

I have dragonboard 410C, but I am unable to get going with respect to Monitor. The linux is debian that comes as part of purchase.

Questions:
How can I connect 1366 x 768 monitor having VGA cable?. I used HDMI to VGA adapter but it did not work.

Is HDMI cable mandatory for connecting to HDMI port of monitor?
Is resolution 1920 x 1080 mandatory?

Is there way to connect the 1366 x 768 monitor using FULL HDMI (1920 x 1080) to VGA connector ( & not routine HDMI to VGA) ?

Completely confused, desperately need help and support


#2

To be honest I would have expected this to work, providing the HDMI converter is doing an adequate job of making the EDID of the VGA monitor available to the kernel.

You’ll only be able to debug this is you have another way to get access to the the devices shell. It use an USB->UART connector (such as the audio mezz board or then 96boards-uart device) or, if you prefer, connect it do a different display and get WiFi working and then (cleanly) shutdown the board. The WiFi settings should be remembered the next time you turn the board on allowing you access the shell through ssh.

Once you have a shell try looking in /sys/class/drm/card0/card0-HDMI-A-1:

root@linaro-alip:/sys/class/drm/card0/card0-HDMI-A-1# cd /sys/class/drm/card0/card0-HDMI-A-1
root@linaro-alip:/sys/class/drm/card0/card0-HDMI-A-1# ls
device	dpms  edid  enabled  modes  power  status  subsystem  uevent
root@linaro-alip:/sys/class/drm/card0/card0-HDMI-A-1# cat enabled
enabled
root@linaro-alip:/sys/class/drm/card0/card0-HDMI-A-1# cat status
connected
root@linaro-alip:/sys/class/drm/card0/card0-HDMI-A-1# cat modes
1920x1080
1920x1080
1920x1080
1600x900
1280x1024
1280x1024
1152x864
1280x720
1280x720
1280x720
1024x768
1024x768
800x600
800x600
720x576
720x480
720x480
640x480
640x480
640x480
720x400
root@linaro-alip:/sys/class/drm/card0/card0-HDMI-A-1# xxd edid
00000000: 00ff ffff ffff ff00 10ac 56f0 5345 5243  ..........V.SERC
00000010: 0f18 0103 8033 1d78 eae5 95a6 5652 9d27  .....3.x....VR.'
00000020: 1050 54a5 4b00 714f 8180 a9c0 d1c0 0101  .PT.K.qO........
00000030: 0101 0101 0101 023a 8018 7138 2d40 582c  .......:..q8-@X,
00000040: 4500 fd1e 1100 001e 0000 00ff 0034 464e  E............4FN
00000050: 4a54 3434 4243 5245 530a 0000 00fc 0044  JT44BCRES......D
00000060: 454c 4c20 555a 3233 3135 480a 0000 00fd  ELL UZ2315H.....
00000070: 0038 4c1e 5311 000a 2020 2020 2020 016d  .8L.S...      .m
00000080: 0203 1ff1 4c90 1f01 0203 0712 1604 1314  ....L...........
00000090: 0523 091f 0765 030c 0010 0083 0100 0002  .#...e..........
000000a0: 3a80 1871 382d 4058 2c45 00fd 1e11 0000  :..q8-@X,E......
000000b0: 1e01 1d80 1871 1c16 2058 2c25 00fd 1e11  .....q.. X,%....
000000c0: 0000 9e01 1d00 7251 d01e 206e 2855 00fd  ......rQ.. n(U..
000000d0: 1e11 0000 1e8c 0ad0 8a20 e02d 1010 3e96  ......... .-..>.
000000e0: 00fd 1e11 0000 1800 0000 0000 0000 0000  ................
000000f0: 0000 0000 0000 0000 0000 0000 0000 00cf  ................