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WSAL21316 – 2.8inch HDMI LCD (H)/en

Aus JW Tech Wiki

Documentation notice: This technical documentation was independently rewritten from an archived supplier source. Check technical details and commands against the product version and manufacturer documentation before use.

Summary

The 2.8-inch HDMI LCD (H) is a compact IPS display with 480×640 resolution, 5-point capacitive touch, and an optically bonded glass surface. It works with Raspberry Pi, Jetson Nano, and as an external monitor under Windows.

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Technical overview

  • Resolution: 480 × 640 pixels in portrait orientation
  • 5-point capacitive touch on toughened glass (6H hardness)
  • Optical bonding reduces reflections and improves contrast
  • Interfaces: HDMI, USB-C (power/touch), I²C (touch)
  • Raspberry Pi connection via pogo pins on the back
  • Supported OS: Raspberry Pi OS, Ubuntu, Kali, Retropie, Win10 IoT (Pi); Ubuntu (Jetson Nano); Windows 7–11 (PC)
  • Brightness is software-adjustable for power saving
  • Defaults to portrait; landscape requires manual rotation settings

Commands and examples – verify before use:  

hdmi_force_hotplug=1
hdmi_group=2
hdmi_mode=87
hdmi_timings=480 0 100 16 100 640 0 100 20 100 0 0 0 60 0 42000000 6
dtparam=i2c_arm=on
dtoverlay=waveshare-28HDMI-3b
dtoverlay=waveshare-28HDMI-4b
dtoverlay=waveshare-28HDMI-5b
start_x=1
gpu_mem=128
display_rotate=3
xrandr -o 1
fbcon=rotate:3 video=HDMI-A-1:640x480M@60,rotate=90
Option "CalibrationMatrix" "0 1 0 -1 0 1 0 0 1"
sudo apt-get update && sudo apt-get full-upgrade
sudo apt install xserver-xorg-input-synaptics
sudo cp /usr/share/X11/xorg.conf.d/40-libinput.conf /etc/X11/xorg.conf.d/
sudo udevadm control --reload-rules && sudo udevadm trigger

Notes and version constraints

  • The exact hdmi_timings values are version-sensitive and may need adjustment per firmware.
  • DTBO files (waveshare-28HDMI-3b/4b/5b) must be downloaded separately and copied to /boot/overlays.
  • Ubuntu path layout differs between 32-bit and 64-bit versions; the correct gdm3/lightdm path must be verified beforehand.
  • The touch calibration matrix varies by target angle (90°, 180°, 270°).
  • The touch interface switch (USB vs I²C) must be set manually before operation.
  • Missing or outdated drivers may prevent display detection; a system update might be required.

Source and revision record

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