/* * lcd.c * * Created: Mar 2021 * Author: Arjan te Marvelde * * => LCD Address and Type are chosen in uSDR.h! * * This file contains the driver for 16x2 HD44780 based LCD displays. * Many different types exist, so you may need to adapt some of the code. * Most notably the startup sequence and the way bytes are sent over the I2C interface. * But also the register mappings as described below. * * LCD_1804: * --------- * Grove 16x2 LCD HD44780, with integrated JHD1804 I2C bridge (@ 0x3E) * 2 byte interface, * byte0 contains coomand/data, * byte1 contains 8-bit command or data word * * LCD_8574_ADA: * ------------- * Standard 16x2 LCD HD44780, with PCF8574 based Adafruit backpack I2C bridge (@ 0x27) * Same registers, but interface uses 4-bit transfers for data/comand, in bits 3..6 * bit 0 is unused * bit 1 is Register Select (0 for command, 1 for data) * bit 2 is Enable, data/command is transferred on falling edge * bit 3..6 data or command nibble (write high nibble first) * bit 7 is backlight (1 for on) * * LCD_8574_GEN: * ------------- * Standard 16x2 LCD HD44780, with PCF8574 based Generic backpack I2C bridge (@ 0x27) * Same registers, but interface uses 4-bit transfers for data/comand, in bits 4..7 * bit 0 is Register Select (0 for command, 1 for data) * bit 1 is unused * bit 2 is Enable, data/command is transferred on falling edge * bit 3 is backlight (1 for on) * bit 4..7 data or command nibble (write high nibble first) * */ #include #include #include "pico/stdlib.h" #include "hardware/i2c.h" #include "hardware/timer.h" #include "hardware/clocks.h" #include "uSDR.h" #include "lcd.h" /** Generic HD44780 interface **/ // commands #define LCD_CLEARDISPLAY 0x01 // Note: LCD_ENTRYINC is set #define LCD_RETURNHOME 0x02 #define LCD_ENTRYMODESET 0x04 #define LCD_DISPLAYCONTROL 0x08 #define LCD_CURSORSHIFT 0x10 #define LCD_FUNCTIONSET 0x20 #define LCD_SETCGRAMADDR 0x40 #define LCD_SETDDRAMADDR 0x80 // flags for display entry mode: LCD_ENTRYMODESET #define LCD_ENTRYSHIFT 0x01 #define LCD_ENTRYNOSHIFT 0x00 #define LCD_ENTRYINC 0x02 // Also applies to CGRAM writes #define LCD_ENTRYDEC 0x00 // Also applies to CGRAM writes // flags for display on/off control: LCD_DISPLAYCONTROL #define LCD_DISPLAYON 0x04 #define LCD_DISPLAYOFF 0x00 #define LCD_CURSORON 0x02 #define LCD_CURSOROFF 0x00 #define LCD_BLINKON 0x01 #define LCD_BLINKOFF 0x00 // flags for display/cursor shift: LCD_CURSORSHIFT #define LCD_DISPLAYMOVE 0x08 #define LCD_CURSORMOVE 0x00 #define LCD_MOVERIGHT 0x04 #define LCD_MOVELEFT 0x00 // flags for function set: LCD_FUNCTIONSET #define LCD_8BITMODE 0x10 #define LCD_4BITMODE 0x00 #define LCD_2LINE 0x08 #define LCD_1LINE 0x00 #define LCD_5x10DOTS 0x04 #define LCD_5x8DOTS 0x00 /** I2C interface specific mappings **/ // 1804-based specific bitmasks (Seeed/Grove) #define LCD_COMMAND 0x80 #define LCD_DATA 0x40 #define LCD_INIT_1804 (LCD_FUNCTIONSET | LCD_8BITMODE | LCD_2LINE | LCD_5x8DOTS) // 8574-based specific bitmasks (Adafruit) #define LCD_COMMAND_ADA 0x00 #define LCD_DATA_ADA 0x02 #define LCD_BACKLIGHT_ADA 0x80 #define LCD_ENABLE_ADA 0x04 #define LCD_INIT_ADA (LCD_FUNCTIONSET | LCD_4BITMODE | LCD_2LINE | LCD_5x8DOTS) // 8574-based specific bitmasks (Generic) #define LCD_COMMAND_GEN 0x00 #define LCD_DATA_GEN 0x01 #define LCD_ENABLE_GEN 0x04 #define LCD_BACKLIGHT_GEN 0x08 #define LCD_INIT_GEN (LCD_FUNCTIONSET | LCD_4BITMODE | LCD_2LINE | LCD_5x8DOTS) #if (LCD_TYPE == LCD_1804) #define LCD_START LCD_INIT_1804 #define LCD_INIT_FUNCTION LCD_INIT_1804 #elif (LCD_TYPE == LCD_8574_ADA) #define LCD_START 0x30 #define LCD_INIT_FUNCTION LCD_INIT_ADA #elif (LCD_TYPE == LCD_8574_GEN) #define LCD_START 0x30 #define LCD_INIT_FUNCTION LCD_INIT_GEN #endif /* * User defined (CGRAM) characters * Display RAM addresses 0x00-0x1f for top row and 0x40-0x5f for bottom row * Available character Generator addresses are 0x00-0x07 */ uint8_t cgram[8][8] = { {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}, // 0x00: blank {0x00, 0x00, 0x00, 0x00, 0x00, 0x1f, 0x00, 0x00}, // 0x01: Level 1 {0x00, 0x00, 0x00, 0x00, 0x1f, 0x1f, 0x00, 0x00}, // 0x02: Level 2 {0x00, 0x00, 0x00, 0x1f, 0x1f, 0x1f, 0x00, 0x00}, // 0x03: Level 3 {0x00, 0x00, 0x1f, 0x1f, 0x1f, 0x1f, 0x00, 0x00}, // 0x04: Level 4 {0x00, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x00, 0x00}, // 0x05: Level 5 {0x00, 0x04, 0x04, 0x04, 0x15, 0x0e, 0x04, 0x00}, // 0x06: Receive arrow down {0x04, 0x0e, 0x15, 0x04, 0x04, 0x04, 0x00, 0x00} // 0x07: Transmit arrow up }; /* * Transfer 1 byte to LCD * --> this function is interface dependent */ void lcd_sendbyte(uint8_t command, uint8_t data) { #if LCD_TYPE == LCD_1804 uint8_t txdata[2]; // Write command/data flag and data byte txdata[0] = (command?LCD_COMMAND:LCD_DATA); txdata[1] = data; i2c_put_data(i2c1, I2C_LCD, txdata, 2, false); #endif #if LCD_TYPE == LCD_8574_ADA uint8_t high, low; high = (command?LCD_COMMAND_ADA:LCD_DATA_ADA)|((data>>1)&0x78)|LCD_BACKLIGHT_ADA; low = (command?LCD_COMMAND_ADA:LCD_DATA_ADA)|((data<<3)&0x78)|LCD_BACKLIGHT_ADA; // Write high nibble high |= LCD_ENABLE_ADA; i2c_put_data(i2c1, I2C_LCD, &high, 1, false); high &= ~LCD_ENABLE_ADA; i2c_put_data(i2c1, I2C_LCD, &high, 1, false); // Write low nibble low |= LCD_ENABLE_ADA; i2c_put_data(i2c1, I2C_LCD, &low, 1, false); low &= ~LCD_ENABLE_ADA; i2c_put_data(i2c1, I2C_LCD, &low, 1, false); #endif #if LCD_TYPE == LCD_8574_GEN uint8_t high, low; high = (command?LCD_COMMAND_GEN:LCD_DATA_GEN)|((data )&0xf0)|LCD_BACKLIGHT_GEN; low = (command?LCD_COMMAND_GEN:LCD_DATA_GEN)|((data<<4)&0xf0)|LCD_BACKLIGHT_GEN; // Write high nibble high |= LCD_ENABLE_GEN; i2c_put_data(i2c1, I2C_LCD, &high, 1, false); high &= ~LCD_ENABLE_GEN; i2c_put_data(i2c1, I2C_LCD, &high, 1, false); // Write low nibble low |= LCD_ENABLE_GEN; i2c_put_data(i2c1, I2C_LCD, &low, 1, false); low &= ~LCD_ENABLE_GEN; i2c_put_data(i2c1, I2C_LCD, &low, 1, false); #endif } /* * It seems that there is too much init here, but it doesn't harm either. */ void lcd_init(void) { uint8_t i; /* HD44780 start sequence */ sleep_ms(500); i = LCD_START; lcd_sendbyte(true, i); sleep_us(4500); lcd_sendbyte(true, i); sleep_us(100); lcd_sendbyte(true, i); /* Initialize function set */ lcd_sendbyte(true, LCD_INIT_FUNCTION); /* Initialize display control */ lcd_sendbyte(true, LCD_DISPLAYCONTROL | LCD_DISPLAYON | LCD_CURSOROFF | LCD_BLINKOFF); /* Initialize entry mode set */ lcd_sendbyte(true, LCD_ENTRYMODESET | LCD_ENTRYINC | LCD_ENTRYNOSHIFT); /* Initialize display */ // lcd_sendbyte(true, LCD_DISPLAYCONTROL | LCD_DISPLAYON | LCD_CURSOROFF | LCD_BLINKOFF); lcd_sendbyte(true, LCD_CLEARDISPLAY); sleep_ms(2); lcd_sendbyte(true, LCD_RETURNHOME); sleep_ms(2); /* Load CGRAM */ for (i=0; i<8; i++) { lcd_sendbyte(true, LCD_SETCGRAMADDR | (i<<3)); //Set CGRAM address for (int j=0; j<8; j++) lcd_sendbyte(false, cgram[i][j]); // One byte at a time } } void lcd_clear(void) { lcd_sendbyte(true, LCD_CLEARDISPLAY); sleep_ms(2); } void lcd_curxy(uint8_t x, uint8_t y, bool on) { uint8_t txdata[3]; x &= 0x0f; // Clip range y &= 0x01; lcd_sendbyte(true, (x | 0x80 | (y==1?0x40:0x00))); lcd_sendbyte(true, LCD_DISPLAYCONTROL | LCD_DISPLAYON | (on?LCD_CURSORON:LCD_CURSOROFF) | LCD_BLINKOFF); } void lcd_putxy(uint8_t x, uint8_t y, uint8_t c) { x &= 0x0f; // Clip range y &= 0x01; lcd_sendbyte(true, (x | 0x80 | (y==1?0x40:0x00))); lcd_sendbyte(false, c); } void lcd_writexy(uint8_t x, uint8_t y, uint8_t *s) { uint8_t i, len; x &= 0x0f; // Clip range y &= 0x01; lcd_sendbyte(true, (x | 0x80 | (y==1?0x40:0x00))); len = strlen(s); len = (len>(16-x))?(16-x):len; // Clip range for(i=0; i