I have recently purchased a HTT50G-TTPC-BLM-B0-H5-CH-V5 from Digikey
Under both Windows 10 (intel graphics), and on a Raspberry Pi 4 (running both latest and legacy rasbian) the display constantly flickers, implying the timing is wrong.
While it is specified as working at 60Hz, if I read and decode the EDID data (e.g. using https://people.freedesktop.org/~imirkin/edid-decode/), it actually reports itself as being 67.73Hz
On Windows, I cannot change the timing from this (presumably incorrect) value, even if I tick "show modes not supported" in display adaptor properties.
Under linux, I have tried the following. All show the same flickering:
- Running a clean install of the latest Raspberry Pi OS, and letting it autodetect
- Changing the kernel command line on latest raspi OS, which does not support setting resolutions in config.txt, appending With this, I get this output at boot, which looks suspicious
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video=HDMI-A-1:800x480M@60
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vc4-drm gpu: [drm] User-defined mode not supported: "800x480": 60 29605 800 816 896 992 480 481 484 497 0x20 0x6 [\code] [*] Running legacy Raspberry Pi OS, and putting in the recommended settings (page 9 of the user manual) into boot/config.txt [*] Forcing 60Hz (well, 58.91) with [url=https://wiki.st.com/stm32mpu/wiki/DRM_KMS_overview#modetest_-28DRM-2FKMS_test_tool-29]modetest[/url], [code] sudo modetest -M vc4 -s 32@96:800x480-58.91
- Forcing 67Hz (the other supported mode) with
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sudo modetest -M vc4 -s 32@96:800x480-67.73
- What are the full timing settings (including blanking) for this LCD?
- Why does the EDID report the refresh rate as 67.7Hz, when the docs say 60Hz?
- Is there a known working set of settings for the raspberry pi 4?