LCD Module

Illustration for LCD Module documentation

Summary

This guide covers connecting and configuring LCD display modules with the Banana Pro and Banana Pi. The Allwinner A20 SoC supports multiple display interfaces, and with the correct hardware hookup and Fex configuration you can drive a variety of LCD panels directly from the board.

Who This Is For

Hardware enthusiasts and embedded developers who want to attach an LCD panel to their Banana Pro or Banana Pi for desktop use, kiosk displays, or custom projects.

What You Will Do

  • Identify supported LCD interfaces on the board.
  • Physically connect an LCD module.
  • Configure the Fex file for correct display timings.
  • Test and verify display output.

Supported LCD Interfaces

The Banana Pro and Banana Pi expose two main LCD interfaces through their board connectors:

  • LVDS (Low-Voltage Differential Signalling): Used by most 7-inch and 10-inch panels sold for Allwinner boards. Provides a clean, high-speed connection with minimal cabling.
  • Parallel RGB: A simpler interface available on the expansion header. Suitable for smaller, lower-resolution panels but requires more signal lines.

Step-by-Step Procedure

Step 1 — Power Off the Board

Always disconnect the power supply before attaching or detaching any ribbon cable or LCD connector. The display interface pins are not hot-pluggable.

Step 2 — Connect the LCD Ribbon Cable

Locate the LVDS connector on the board (a flat, 40-pin FPC connector near the edge). Lift the latch, slide the ribbon cable in with the contacts facing down, and press the latch closed. Ensure the cable is seated evenly.

Step 3 — Connect the Backlight Power

Many LCD modules require a separate backlight power connection. Check your panel's datasheet for the backlight voltage (commonly 3.3 V or 5 V) and connect it to the appropriate header pin or an external supply.

Step 4 — Edit the Fex File

Mount the SD card on your host computer and locate the script.bin file on the boot partition. Convert it to a text-based Fex file:

bin2fex script.bin script.fex

Open script.fex and find the [lcd0_para] section. Set the following values to match your panel's datasheet:

  • lcd_x — horizontal resolution (e.g., 1024)
  • lcd_y — vertical resolution (e.g., 600)
  • lcd_dclk_freq — pixel clock frequency in MHz
  • lcd_ht, lcd_hbp, lcd_hspw — horizontal timing
  • lcd_vt, lcd_vbp, lcd_vspw — vertical timing
  • lcd_if — interface type (0 = parallel RGB, 3 = LVDS)

Step 5 — Repack and Copy

fex2bin script.fex script.bin

Copy the updated script.bin back to the boot partition and safely eject the card.

Step 6 — Test the Display

Insert the SD card into the board, connect HDMI as a fallback, and power on. If the LCD panel is configured correctly, the boot console or desktop environment should appear on the LCD.

Verification

A correctly configured LCD will display the Linux framebuffer console or graphical desktop at the expected resolution. Run fbset to confirm the active resolution matches your configuration.

Troubleshooting

  • Blank screen: Double-check ribbon cable orientation and Fex timing values. Ensure the backlight is powered.
  • Wrong resolution or stretched image: Review lcd_x, lcd_y, and timing parameters against the panel datasheet.
  • Flickering or unstable picture: The pixel clock may be set too high. Lower lcd_dclk_freq slightly and retest.
  • Backlight on but no image: The interface type (lcd_if) may be incorrect — verify LVDS vs parallel RGB.

Related Pages

Author: LeMaker Documentation Team
Last updated: 2026-02-10