BPI-CM9-Linux/aml-comp/vendor/amlogic/aml_commonlib/aml_spi_display

Second Display

A utility for controlling a secondary SPI display (ST7789V3) on Linux systems.

Overview

This tool allows you to display images, animations, and a digital clock on a 320x170 pixel SPI display. It supports:

• Displaying single PNG images
• Showing a digital clock with customizable digits
• Playing animations from a sequence of PNG files
• Setting the display to solid black or white

Requirements

• Linux system with SPI display support
• libpng development libraries
• pthread support

Installation

1. Clone this repository:

   git clone https://github.com/yourusername/secondDisplay.git
   cd secondDisplay
   

2. Compile the program:

   gcc -o secondDisplay secondDisplay.c -lpng -lpthread
   

Usage

Display a Single Image

./secondDisplay /path/to/image.png

The image should be a PNG file with dimensions 320x170 pixels.

Display a Black Screen

./secondDisplay --black

Display a White Screen

./secondDisplay --white

Display a Digital Clock

./secondDisplay --clock /path/to/digits/folder

The digits folder should contain PNG images named:

• 0.png through 9.png - For the digits 0-9
• colon.png - For the separator between hours and minutes

Each digit image should be 60x80 pixels, and the colon should be 60x80 pixels.

Display an Animation

./secondDisplay --animation /path/to/frames/folder [delay_ms]

• /path/to/frames/folder: Directory containing PNG frames for the animation
• delay_ms: Optional delay between frames in milliseconds (default: 100ms)

The PNG files in the frames folder will be displayed in alphabetical order.

Image Requirements

• All images should be in PNG format
• For full-screen display: 320x170 pixels
• For clock digits: 60x80 pixels
• For colon: 60x80 pixels

Examples

Display a clock using Art Deco style digits:

./secondDisplay --clock ./digits/art_deco

Play an animation with a 200ms delay between frames:

./secondDisplay --animation ./animations/fireworks 200

Troubleshooting

If you encounter issues:

1. Ensure the SPI display device is available at /dev/st7789v3
2. Check that your PNG files have the correct dimensions
3. Verify that you have read/write permissions for the SPI device