/* * ---------------------------------------------------------------------------- * "THE BEER-WARE LICENSE" (Revision 42): * <joerg@FreeBSD.ORG> wrote this file. As long as you retain this notice you * can do whatever you want with this stuff. If we meet some day, and you think * this stuff is worth it, you can buy me a beer in return. Joerg Wunsch * ---------------------------------------------------------------------------- * * HD44780 LCD display driver * * $Id$ */ /* * Send byte b to the LCD. rs is the RS signal (register select), 0 * selects instruction register, 1 selects the data register. */ void hd44780_outbyte(uint8_t b, uint8_t rs); /* * Read one byte from the LCD controller. rs is the RS signal, 0 * selects busy flag (bit 7) and address counter, 1 selects the data * register. */ uint8_t hd44780_inbyte(uint8_t rs); /* * Wait for the busy flag to clear. */ void hd44780_wait_ready(bool islong); /* * Initialize the LCD controller hardware. */ void hd44780_init(void); /* * Prepare the LCD controller pins for powerdown. */ void hd44780_powerdown(void); /* Send a command to the LCD controller. */ #define hd44780_outcmd(n) hd44780_outbyte((n), 0) /* Send a data byte to the LCD controller. */ #define hd44780_outdata(n) hd44780_outbyte((n), 1) /* Read the address counter and busy flag from the LCD. */ #define hd44780_incmd() hd44780_inbyte(0) /* Read the current data byte from the LCD. */ #define hd44780_indata() hd44780_inbyte(1) /* Clear LCD display command. */ #define HD44780_CLR \ 0x01 /* Home cursor command. */ #define HD44780_HOME \ 0x02 /* * Select the entry mode. inc determines whether the address counter * auto-increments, shift selects an automatic display shift. */ #define HD44780_ENTMODE(inc, shift) \ (0x04 | ((inc)? 0x02: 0) | ((shift)? 1: 0)) /* * Selects disp[lay] on/off, cursor on/off, cursor blink[ing] * on/off. */ #define HD44780_DISPCTL(disp, cursor, blink) \ (0x08 | ((disp)? 0x04: 0) | ((cursor)? 0x02: 0) | ((blink)? 1: 0)) /* * With shift = 1, shift display right or left. * With shift = 0, move cursor right or left. */ #define HD44780_SHIFT(shift, right) \ (0x10 | ((shift)? 0x08: 0) | ((right)? 0x04: 0)) /* * Function set. if8bit selects an 8-bit data path, twoline arranges * for a two-line display, font5x10 selects the 5x10 dot font (5x8 * dots if clear). */ #define HD44780_FNSET(if8bit, twoline, font5x10) \ (0x20 | ((if8bit)? 0x10: 0) | ((twoline)? 0x08: 0) | \ ((font5x10)? 0x04: 0)) /* * Set the next character generator address to addr. */ #define HD44780_CGADDR(addr) \ (0x40 | ((addr) & 0x3f)) /* * Set the next display address to addr. */ #define HD44780_DDADDR(addr) \ (0x80 | ((addr) & 0x7f))