JWTechPublisher: Freigegebene technische Dokumentation veröffentlicht; Text-only und noindex

2026-09-05T22:40:03Z

Freigegebene technische Dokumentation veröffentlicht; Text-only und noindex

Neue Seite

__NOINDEX__
'''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 ==
Technical guide for the Waveshare 3.5inch capacitive touch LCD (640×480) with DPI interface, IPS panel and toughened glass cover.

== Related products at JW Tech ==
* [https://shop.jw-tech.eu/p/WSAL19173 WSAL19173 – 3.5inch Capacitive Touch Screen LCD For Raspberry Pi, 640×480, DPI, IPS, Toughened Glass Cover, Low Power]

== Technical overview ==
* Resolution: 640×480 pixels; display type: 3.5-inch IPS with 5-point capacitive touch.
* Connects via the Raspberry Pi 40-pin GPIO header; refresh rate up to 60 Hz through the DPI channel.
* Touch is driven over I2C; the toughened glass cover has a hardness rating of up to 6H.
* Supported systems: Raspberry Pi OS (Bookworm, Trixie, Bullseye, Buster) as well as Ubuntu/Kali.
* For Bookworm/Trixie, three dtoverlay entries are added to config.txt and the matching DTBO file is copied into /boot/overlays.
* For Bullseye, four dtoverlay entries are set; for Buster/Ubuntu, dpi_mode=87, hdmi_timings and other parameters are defined in config.txt.
* Display rotation is performed either via the graphical screen configuration or via cmdline.txt/config.txt entries, depending on the system version.
* When DPI and HDMI outputs are used simultaneously, they share the same rotation value.
* The touch rotation angle is configured on older systems via udev rules (LIBINPUT_CALIBRATION_MATRIX) or an X11 libinput configuration.
* Pinout: RGB signal lines on GPIO pins 1–29, PWM backlight on pin 12, touch I2C on pins 19/23, LCD_CLK on pin 27 and DE on pin 28.

'''Commands and examples – verify before use:'''
<syntaxhighlight lang="text">
dtoverlay=vc4-kms-v3d
dtoverlay=waveshare-35dpi
dtoverlay=waveshare-touch-35dpi
dtoverlay=vc4-kms-DPI-35inch
dtoverlay=waveshare-35dpi-3b-4b
dtoverlay=waveshare-35dpi-3b
dtoverlay=waveshare-35dpi-4b
gpio=0-9=a2
gpio=12-17=a2
gpio=20-25=a2
dtoverlay=dpi18
enable_dpi_lcd=1
display_default_lcd=1
extra_transpose_buffer=2
dpi_group=2
dpi_mode=87
dpi_output_format=0x6f006
hdmi_timings=640 0 20 10 10 480 0 10 5 5 0 0 0 60 0 60000000 1
video=DPI-1:640x480M@60,rotate=90
video=DPI-1:640x480M@60,rotate=180
</syntaxhighlight>

== Notes and version constraints ==
* The exact steps for touch rotation under Bullseye/Buster are truncated in the source text; the full X11 configuration must be completed manually.
* On Raspberry Pi 4, the entry dtoverlay=vc4-fkms-V3D must be commented out; this is version-dependent and requires technician confirmation.
* Extending the cable beyond 10 cm is not recommended; for longer connections, use differential-signal-capable interfaces such as HDMI, MIPI DSI, or LVDS.
* The power consumption figure of 5 V / 130 mA reflects only the stated value; other operating states or additional loads may change actual consumption.
* All configuration files (config.txt, cmdline.txt, udev rules) must be saved before rebooting; forgotten changes only take effect after a restart.

== Source and revision record ==
* [https://www.waveshare.com/wiki/3.5inch_DPI_LCD 3.5inch DPI LCD - Waveshare Wiki]
* Source revision: 105190
* Captured: 2026-09-01T03:59:08+00:00
* SHA-256: <code>c653bdad64dfd99649622bd272f3e509905c044675a692f0afcce617b570e9c7</code>

WSAL19173 – 3.5inch DPI LCD/en - Versionsgeschichte

JWTechPublisher: Freigegebene technische Dokumentation veröffentlicht; Text-only und noindex