Initial work

.gitignore

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+build/

.vscode/c_cpp_properties.json

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+{
+    "configurations": [
+        {
+            "name": "CMake config",
+            "intelliSenseMode": "${default}",
+            "configurationProvider": "ms-vscode.cmake-tools"
+        }
+    ],
+    "version": 4
+}

.vscode/cmake-kits.json

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+[
+    {
+      "name": "gcc-arm",
+      "toolchainFile": "cmake/toolchains/gcc-arm.cmake"
+    }
+]

.vscode/launch.json

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+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+      {
+        "name": "Debug STM32407VG",
+        "type": "cortex-debug",
+        "request": "launch",
+        "servertype": "jlink",
+        "cwd": "${workspaceRoot}",
+        "executable": "./build/hd44780-example",
+        "serverpath": "JLinkGDBServerCLExe", 
+        "device": "STM32F407VG",
+        "interface": "swd",
+        "svdFile": "${workspaceFolder}/STM32F407.svd",
+        "runToEntryPoint": "main"
+      }
+    ]
+}

CHANGELOG.md

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+# v0.1.0 - 04.03.2023
+- initial release

CMakeLists.txt

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+cmake_minimum_required(VERSION 3.16)
+
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+
+project(hd44780 C)
+
+option(BUILD_EXAMPLE "Build library example" ON)
+
+################################################################################
+# HD44780 library
+################################################################################
+
+add_library(hd44780)
+add_library(dsabala::hd44780 ALIAS hd44780)
+
+target_sources(hd44780
+    PRIVATE
+        src/hd44780.c
+    PUBLIC
+        src/hd44780.h
+)
+
+target_include_directories(hd44780
+    PUBLIC
+        $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/src>
+)
+
+################################################################################
+# HD44780 library example
+################################################################################
+
+if(BUILD_EXAMPLE)
+    enable_language(ASM)
+
+    add_executable(hd44780-example)
+
+    set(CPU_OPTIONS
+        -mthumb 
+        -mcpu=cortex-m4
+        -mfpu=fpv4-sp-d16
+        -mfloat-abi=hard
+    )
+
+    target_compile_options(hd44780
+        PRIVATE
+            ${CPU_OPTIONS}
+    )
+
+    target_link_libraries(hd44780-example
+        PRIVATE
+            hd44780
+    )
+
+    target_compile_options(hd44780-example
+        PRIVATE
+            -Og
+            -Wall
+            -Wextra
+            -fdata-sections
+            -ffunction-sections
+            -Wno-unused-parameter
+            ${CPU_OPTIONS}
+    )
+
+    target_compile_definitions(hd44780-example
+        PRIVATE
+            STM32F407xx
+            USE_HAL_DRIVER
+            HSE_VALUE=8000000U
+    )
+
+    target_include_directories(hd44780-example
+        PRIVATE 
+            ${CMAKE_CURRENT_SOURCE_DIR}/example/src
+            ${CMAKE_CURRENT_SOURCE_DIR}/example/stm32f4-drivers/include
+    )
+
+    target_sources(hd44780-example
+        PRIVATE
+            example/src/bsp_lcd.c
+            example/src/main.c
+            example/stm32f4-drivers/source/startup_stm32f407xx.s
+            example/stm32f4-drivers/source/stm32f4xx_hal.c
+            example/stm32f4-drivers/source/stm32f4xx_hal_cortex.c
+            example/stm32f4-drivers/source/stm32f4xx_hal_gpio.c
+            example/stm32f4-drivers/source/system_stm32f4xx.c
+    )
+
+    target_link_options(hd44780-example
+        PRIVATE 
+            -T${CMAKE_CURRENT_SOURCE_DIR}/example/stm32f4-drivers/STM32F407VGTx_FLASH.ld
+            -specs=nosys.specs 
+            -lnosys
+            -lc
+            -Wl,-Map=${PROJECT_NAME}.map,--gc-sections,--cref,--print-memory-usage 
+            ${CPU_OPTIONS}
+    )
+
+endif()

README.md

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-# hd44780
-Fully loaded, dependency free, fail-safe, HD44780 driver
+# Dependency free, UTF-8 ready, HD44780 driver
+
+<img src="https://raw.githubusercontent.com/dsabala/hd44780/master/hd44780.gif">
+
+[![Github Issues](https://img.shields.io/github/issues/dsabala/hd44780?style=plastic)](http://github.com/dsabala/hd44780/issues)
+[![Github Releases](https://img.shields.io/github/v/release/dsabala/hd44780?style=plastic)](https://github.com/dsabala/hd44780/releases)
+[![GitHub license](https://img.shields.io/github/license/dsabala/hd44780?style=plastic)](https://raw.githubusercontent.com/dsabala/hd44780/master/LICENSE)
+
+# Overview
+
+Yet another HD44780 C driver. It might fit your needs if you are interested in one of its core features:
+- **dependency free** - its free from any Arduino or STM HAL headers, only standard library headers are used
+- **fail-safe** - it will handle hardware fails gently and return error code
+- **UTF-8 string support** - minimalistic support for UTF-8 strings (8 custom characters can be mapped) 
+- **decoupled from underlying drivers** - by callback functions
+- **multi-instantaneous** - more than one LCDs can be driven
+- **support both communication modes** 4bit and 8bit interface with busy flag read
+- **MIT license** - just fork this library and modify it to your needs
+- **ready example** - for STM32F407G-DISC1 evalboard
+
+Nothing comes without flaws, the disadvantages of this driver are:
+- **arcane callbacks have to be implemented** - you might found it overcomplicated
+- **binary size is not prority** - better choose other lib if your target platform lacks ROM memory
+- **UTF-8 support might be too minimalistic** - its only 8 characters that can be mapped to CGRAM memory of HD44780
+- **some features like shifting text are not implemented** - its still work in progrss
+
+# Glimpse into features
+
+Interface overview:
+There are 8 poublic functions that covers 95% of HD44780 functionality
+```c
+hd44780_ret_e hd44780_init(const hd44780_ctx* const ctx);
+hd44780_ret_e hd44780_clear(const hd44780_ctx* const ctx);
+hd44780_ret_e hd44780_write_text(const hd44780_ctx* const ctx, const char* text);
+hd44780_ret_e hd44780_set_pos(const hd44780_ctx* const ctx, uint8_t row, uint8_t column);
+hd44780_ret_e hd44780_cursor_cfg(const hd44780_ctx* const ctx, hd44780_cursor cursor_cfg);
+hd44780_ret_e hd44780_display_off(const hd44780_ctx* const ctx);
+hd44780_ret_e hd44780_def_char(const hd44780_ctx* const ctx, uint8_t index, const uint8_t* const pattern);
+hd44780_ret_e hd44780_disp_char(const hd44780_ctx* const ctx, uint8_t index);
+```
+
+Return codes:
+```c
+typedef enum {
+  HD44780_OK = 0,                 /**< Success */
+  HD44780_INV_ARG = 1,            /**< Invalid argument */
+  HD44780_TIMEOUT = 2,            /**< Timeout */
+  HD44780_CUSTOM_CHARS_INV = 3,   /**< Custom character array invalid */
+  HD44780_CHAR_NOT_FOUND = 4,     /**< Custom character not found */
+} hd44780_ret_e;
+```
+
+Usage examples:
+```c
+/* Get driver context from library - application glue code */
+const hd44780_ctx* const lcd_ctx = hd44780_instance_ctx_get();
+
+/* Initialise display */
+hd44780_init(lcd_ctx);
+
+/* Set positon to first line and write text */
+hd44780_set_pos(lcd_ctx, 0, 0);
+hd44780_write_text(lcd_ctx, "Bonjour collègues 🍌"); /* UTF-8 is supported */
+```
+
+Example of UTF-8 custom characters map:
+
+```c
+static const character_mapping mappings[3] = {
+  {
+      .utf_8_code = U'è',
+      .character_bitmap = {0b01000, 0b00100, 0b01110, 0b10001, 0b11111, 0b10000, 0b01110, 0b00000},
+  },
+  {
+      .utf_8_code = U'🍌',
+      .character_bitmap = {0b01000, 0b00110, 0b00011, 0b00011, 0b00011, 0b00110, 0b01100, 0b10000},
+  }
+};
+```
+
+Full description of callbacks that user of library have to implement is available
+in header file.
+
+# Status
+This library is not finished, there are surely bugs and things that can be simplified
+or features that can be added. It was tested only on 4x20 display of one manufacturer. 
+I decided to release it in this stage because 
+I have no experience with UTF-8 and open source libraries and have no idea if
+this library can be useful for someone.

cmake/toolchains/gcc-arm.cmake

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+set(CMAKE_SYSTEM_NAME Generic)
+set(CMAKE_SYSTEM_PROCESSOR arm)
+set(CMAKE_C_COMPILER arm-none-eabi-gcc)
+set(CMAKE_CXX_COMPILER arm-none-eabi-g++)
+set(CMAKE_OBJCOPY arm-none-eabi-objcopy)
+set(CMAKE_SIZE_UTIL arm-none-eabi-size)
+set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY)