Dazzler and Seedstudio HDMI display.

[alex66]

Hi,
Just got Gameduino 3X Dazzler from Crowd Supply. Connected to Arduino Uno and Seeedstudio 5in 720x1280 HDMI display. There is no issues with arduino communication. But HDMI is something wrong. Display resolution is  720x1280 when Dazzler 1280x720. Is any way I can correct this by making some changes to h. or cpp. file? Pictures with 3 different examples uploaded to Arduino attached.

       

[jamesbowman]

Ha, that's very interesting. That monitor is exotic!

It's a display that claims HDMI, but is actually sideways. HDMI 720p is 1280x720. This display is 720x1280!

www.seeedstudio.com/5-inch-720x1280-HDMI-IPS-LCD-Display-p-2858.html

So it needs custom video timings. Their user guide gives some recipes for RPi on 

docs.google.com/viewer?url=https://github.com/SeeedDocument/Pi_screen/raw/master/Instructions_for_use.pdf

The Dazzler's video timings are set by the EVE registers. After GD.begin() you can change them.

However after a bit of searching I can't find any proper documentation of the frame timings. So here's a wild guess, based on the fact that it is already syncing:

GD.wr16(REG_HCYCLE, 800);
GD.wr16(REG_HSIZE, 720);
GD.wr16(REG_VCYCLE, 1350);
GD.wr16(REG_VSIZE, 1280);
(The numbers 800 and 1350 are guesses)

*If* that worked, doing:

GD.cmd_setrotate(2)

rotates the screen 90 degrees, into a "landscape" layout.