STM32-HAL-HD44780

Overview

This is a simple library for STM32 32-bit Arm Cortex MCUs to work with the HD44780 16x2 Lcd module.

To develop this library it was used STM32CubeIDE and HAL APIs to interact with peripherals and low-level resources.

In this repository you will find the LCD library, ready to attach to your new project and a project example, tested with the STM32F4DISCOVERY board.

In this library the HD44780 controller is used in 4-bits mode and driven by the PCF8574 I2C I/O expander.

Examples

SMT32F4DISCOVERY

Brief description of the example attached

#include "lcd.h"
#include <stdio.h"
int main(){
  LCD_HandleTypeDef lcd;

  lcd_init_I2C(&lcd, &hi2c1);

  lcd_print_string(&lcd, "LCD library");
  HAL_Delay(2000);

  lcd_set_cursor(&lcd, DISPLAY_ROW_2, DISPLAY_COLUMN_1);

  lcd_send_command(&lcd, LCD_CMD_Don_nC_BL);

  lcd_print_string(&lcd, "LCD library");
  HAL_Delay(2000);

  lcd_display_clear(&lcd);
  lcd_display_return_home(&lcd);
  lcd_send_command(&lcd, LCD_CMD_Don_nC_nBL);

  uint16_t date_num[3] = {3, 11, 2023};
  char date_char[20];
  sprintf(date_char, "0%d/%d/%d", date_num[0], date_num[1], date_num[2]);

  lcd_print_string(&lcd, date_char);
  HAL_Delay(2000);

  lcd_set_cursor(&lcd, DISPLAY_ROW_2, DISPLAY_COLUMN_4);
  lcd_print_string(&lcd, "HD44780");

  while(1){

  }
}

In this example it's shown how to use differents APIs to print several messages as well as a set of integers.

Documentation

A brief documentation of the structures and functions provided by the library are shown below. For detailed instructions, refer to the doxygen compliant documentation within the lcd.c file.

Macro definitions

List of important macro definitions with a brief description is shown below.

Name	Description
SLAVE_ADDRESS_PCF	PCF8574 I2C I/O expander device address.

Structure

List of structures provided with the library with a brief description is shown below.

Name	Description
LCD_HandleTypeDef	Struct to handle the I2C device addres and the I2C Handler.

Functions

List of functions provided with the library with a brief description is shown below.

Name	Description
lcd_init_I2C	Initialize the LCD_HandleTypeDef struct with the information to work with the I2C communication bus.
lcd_init	Initialize HD44780 controller following the steps provided by the manufacturer.
lcd_send_command	Set the display in a particular state by sending a command.
lcd_print_char	In char of print a character on the LCD
lcd_display_clear	Clear the display
lcd_display_return_home	Move the cursor to the position (1, 1)
lcd_print_string	Split the incoming string into individual characters and send them one by one
lcd_set_cursor	Move the cursor to the desire position