The old 5.x font converter (using PHP) was removed in January 2020 as it is no longer compatible with modern versions of LittlevGL. The last commit containing it is ec7d2676b36a27fa13b21162aca1476ad8456ec5.

This repository houses a number of converter utilities for LittlevGL. Note that the 6.0+ TTF/OTF font converter has its own repository at https://github.com/littlevgl/lv_font_conv.

• Image converter: https://littlevgl.com/image-to-c-array
• Hex font converter

Here you you can see how they work or download them to run offline.

This guide shows how to use the converters offline in a command line on Linux

1. Install PHP: sudo apt-get install php7.2-cli
2. Intall extensions

2.a For the Image manipulator: sudo apt-get install php7.2-gd

3. Clone or download the lv_utils repository: git clone https://github.com/littlevgl/lv_utils.git
4. Go to the lv_utils directory.

For Mac OSX using Homebrew

Because the php version installed by xcode might not have the GD graphics library installed, you need to install the Homebrew version. Once installed, you will need to find where it was installed and reference the complete path to php when running the commands shown on this page. The example below in step 4 happened to be the installation location on my Mac for php version 7.3.3.

1. Install xcode: install via the app store
2. Install xcode CLI tools: xcode-select --install
3. Install PHP: brew install php
4. Check the install: /usr/local/Cellar/php/7.3.3/bin/php --version
5. Continue with step 3 in the installation instructions for Linux

1. Copy a BMP, JPG or PNG file you want to use into the lv_utils directory
2. Run the script: php img_conv_core.php "name=wallpaper&img=red_flower.png"
3. Chek the created C file in lv_utils directory.

The required arguments of the script:

• name name of the output file and image
• img an image file

Optional arguments:

• cf color format. Possible values are: true_color, true_color_alpha, true_color_chroma, indexed_1, indexed_2, indexed_4, indexed_8, alpha_1, alpha_2, alpha_4, alpha_8, raw, raw_alpha, raw_chroma. The default is: true_color.
• format C array or Binary output. Possible values are: c_array, bin_332, bin_565, bin_565_swap, bin_888. Default is: c_array.

Note: You may need to increase memory_limit in php.ini if PHP reports an error similar to this:

PHP Fatal error:  Allowed memory size of 134217728 bytes exhausted (tried to allocate 21570880 bytes) in lv_utils/img_conv_core.php`

Convert a bunny.png with alpha for all pixels to C array: php img_conv_core.php "name=icon&img=bunny.png&format=c_array&cf=true_color_alpha"

• For C arrays
  • Copy the result C file into your LittlevGL project
  • In a C file of your application declare the image as: extern const lv_img_t my_image_name; or LV_IMG_DECLARE(my_image_name);
  • Set the image for an lv_img object: lv_img_set_src(img1, &my_image_name);
• For externally binary files (e.g. SD card)
  • Set up a new driver. To learn more read the Tutorial.
  • Set the image for an lv_img object: lv_img_set_src(img1, "S:/path/to/image");