/** * @file lcd_1602.h * @brief Header for PCF8574-backed HD44780 (16x2) LCD driver * @author Kevin Thomas * @date 2025 * * MIT License * * Copyright (c) 2025 Kevin Thomas * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all * copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ #ifndef LCD_1602_H #define LCD_1602_H #include #include "pico/stdlib.h" #include "hardware/i2c.h" /** * @brief Initialize the LCD driver over I2C * * Configures the internal driver state and performs the HD44780 initialization * sequence. The driver does not configure I2C pins or call i2c_init; that * must be done by the caller prior to calling this function. * * @param i2c Pointer to the I2C instance (e.g. i2c0 or i2c1) * @param pcf_addr PCF8574 I2C address (commonly 0x27 or 0x3F) * @param nibble_shift Bit shift applied to 4-bit nibbles (commonly 4 or 0) * @param backlight_mask PCF8574 bit mask that controls the backlight */ void lcd_i2c_init(i2c_inst_t *i2c, uint8_t pcf_addr, int nibble_shift, uint8_t backlight_mask); /** * @brief Clear the LCD display * * Clears the display and returns the cursor to the home position. This * call blocks for the duration required by the HD44780 controller. */ void lcd_clear(void); /** * @brief Set the cursor position * * @param line Line number (0 or 1) * @param position Column (0..15) */ void lcd_set_cursor(int line, int position); /** * @brief Write a null-terminated string to the display * * @param s The string to write (ASCII) */ void lcd_puts(const char *s); #endif // LCD_1602_H