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6d61381d2a
The expandable GPIO API requires the comparison of structured GPIO types. This means that inline functions must be used instead of direct comparisons. For the migration process, drivers must first be changed so that they use the inline comparison functions.
292 lines
8.0 KiB
C
292 lines
8.0 KiB
C
/*
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* Copyright (C) 2017 HAW Hamburg
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*
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* This file is subject to the terms and conditions of the GNU Lesser
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* General Public License v2.1. See the file LICENSE in the top level
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* directory for more details.
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*/
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/**
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* @ingroup drivers_hd44780
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*
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* @{
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* @file
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* @brief Driver for the HD44780 LCD
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*
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* @note The display is also known as LCM1602C from Arduino kits
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*
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* @author Sebastian Meiling <s@mlng.net>
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*
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* @}
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*/
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#include <assert.h>
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#include <string.h>
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#include "log.h"
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#include "periph/gpio.h"
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#include "xtimer.h"
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#include "hd44780.h"
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#include "hd44780_internal.h"
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static inline void _command(const hd44780_t *dev, uint8_t value);
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static void _pulse(const hd44780_t *dev);
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static void _send(const hd44780_t *dev, uint8_t value, hd44780_state_t state);
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static void _write_bits(const hd44780_t *dev, uint8_t bits, uint8_t value);
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/**
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* @brief Send a command to the display
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*
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* @param[in] dev device descriptor of display to initialize
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* @param[in] value the command
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*/
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static inline void _command(const hd44780_t *dev, uint8_t value)
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{
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_send(dev, value, HD44780_OFF);
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}
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/**
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* @brief Send a pulse to the display to enable new state
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*
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* @param[in] dev device descriptor of display to initialize
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*/
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static void _pulse(const hd44780_t *dev)
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{
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gpio_clear(dev->p.enable);
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xtimer_usleep(HD44780_PULSE_WAIT_SHORT);
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gpio_set(dev->p.enable);
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xtimer_usleep(HD44780_PULSE_WAIT_SHORT);
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gpio_clear(dev->p.enable);
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xtimer_usleep(HD44780_PULSE_WAIT_LONG);
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}
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/**
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* @brief Send a data value to the display
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*
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* @param[in] dev device descriptor of display to initialize
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* @param[in] value the data value, either char or command
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* @param[in] state send state, to distinguish chars and commands
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*/
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static void _send(const hd44780_t *dev, uint8_t value, hd44780_state_t state)
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{
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(state == HD44780_ON) ? gpio_set(dev->p.rs) : gpio_clear(dev->p.rs);
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/* if RW pin is available, set it to LOW */
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if (gpio_is_valid(dev->p.rw)) {
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gpio_clear(dev->p.rw);
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}
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/* write data in 8Bit or 4Bit mode */
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if (dev->flag & HD44780_8BITMODE) {
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_write_bits(dev, 8, value);
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}
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else {
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_write_bits(dev, 4, value>>4);
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_write_bits(dev, 4, value);
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}
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}
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static void _write_bits(const hd44780_t *dev, uint8_t bits, uint8_t value)
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{
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for (unsigned i = 0; i < bits; ++i) {
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if ((value >> i) & 0x01) {
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gpio_set(dev->p.data[i]);
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}
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else {
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gpio_clear(dev->p.data[i]);
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}
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}
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_pulse(dev);
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}
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int hd44780_init(hd44780_t *dev, const hd44780_params_t *params)
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{
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/* write config params to device descriptor */
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dev->p = *params;
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/* verify cols and rows */
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if ((dev->p.cols > HD44780_MAX_COLS) || (dev->p.rows > HD44780_MAX_ROWS)
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|| (dev->p.rows * dev->p.cols > 80)) {
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LOG_ERROR("hd44780_init: invalid LCD size!\n");
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return -1;
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}
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dev->flag = 0;
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/* set mode depending on configured pins */
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if (gpio_is_valid(dev->p.data[4])) {
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dev->flag |= HD44780_8BITMODE;
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}
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else {
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dev->flag |= HD44780_4BITMODE;
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}
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/* set flag for 1 or 2 row mode, 4 rows are 2 rows split half */
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if (dev->p.rows > 1) {
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dev->flag |= HD44780_2LINE;
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}
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else {
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dev->flag |= HD44780_1LINE;
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}
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/* set char size to 5x8 as default, 5x10 is hardly used by LCDs anyway */
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dev->flag |= HD44780_5x8DOTS;
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/* calc and set row offsets, depending on number of columns */
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dev->roff[0] = 0x00;
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dev->roff[1] = 0x40;
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dev->roff[2] = 0x00 + dev->p.cols;
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dev->roff[3] = 0x40 + dev->p.cols;
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gpio_init(dev->p.rs, GPIO_OUT);
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/* RW (read/write) of LCD not required, set it to GPIO_UNDEF */
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if (gpio_is_valid(dev->p.rw)) {
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gpio_init(dev->p.rw, GPIO_OUT);
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}
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gpio_init(dev->p.enable, GPIO_OUT);
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/* configure all data pins as output */
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for (int i = 0; i < ((dev->flag & HD44780_8BITMODE) ? 8 : 4); ++i) {
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gpio_init(dev->p.data[i], GPIO_OUT);
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}
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/* see hitachi HD44780 datasheet pages 45/46 for init specs */
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xtimer_usleep(HD44780_INIT_WAIT_XXL);
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gpio_clear(dev->p.rs);
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gpio_clear(dev->p.enable);
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if (gpio_is_valid(dev->p.rw)) {
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gpio_clear(dev->p.rw);
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}
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/* put the LCD into 4 bit or 8 bit mode */
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if (!(dev->flag & HD44780_8BITMODE)) {
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/* see hitachi HD44780 datasheet figure 24, pg 46 */
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_write_bits(dev, 4, 0x03);
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xtimer_usleep(HD44780_INIT_WAIT_LONG);
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_write_bits(dev, 4, 0x03);
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xtimer_usleep(HD44780_INIT_WAIT_LONG);
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_write_bits(dev, 4, 0x03);
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xtimer_usleep(HD44780_INIT_WAIT_SHORT);
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_write_bits(dev, 4, 0x02);
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} else {
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/* see hitachi HD44780 datasheet page 45 figure 23 */
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_command(dev, HD44780_FUNCTIONSET | dev->flag);
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xtimer_usleep(HD44780_INIT_WAIT_LONG); /* wait more than 4.1ms */
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_command(dev, HD44780_FUNCTIONSET | dev->flag);
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xtimer_usleep(HD44780_INIT_WAIT_SHORT);
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_command(dev, HD44780_FUNCTIONSET | dev->flag);
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}
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_command(dev, HD44780_FUNCTIONSET | dev->flag);
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/* turn the display on with no cursor or blinking default, and clear */
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dev->ctrl = HD44780_DISPLAYON | HD44780_CURSOROFF | HD44780_BLINKOFF;
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hd44780_display(dev, HD44780_ON);
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hd44780_clear(dev);
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/* Initialize to default text direction for western languages */
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dev->mode = HD44780_ENTRYLEFT | HD44780_ENTRYSHIFTDECREMENT;
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_command(dev, HD44780_ENTRYMODESET | dev->mode);
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return 0;
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}
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void hd44780_clear(const hd44780_t *dev)
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{
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_command(dev, HD44780_CLEARDISPLAY);
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xtimer_usleep(HD44780_CMD_WAIT);
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}
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void hd44780_home(const hd44780_t *dev)
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{
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_command(dev, HD44780_RETURNHOME);
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xtimer_usleep(HD44780_CMD_WAIT);
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}
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void hd44780_set_cursor(const hd44780_t *dev, uint8_t col, uint8_t row)
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{
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if (row >= dev->p.rows) {
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row = dev->p.rows - 1;
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}
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_command(dev, HD44780_SETDDRAMADDR | (col + dev->roff[row]));
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}
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void hd44780_display(hd44780_t *dev, hd44780_state_t state)
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{
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if (state == HD44780_ON) {
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dev->ctrl |= HD44780_DISPLAYON;
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}
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else {
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dev->ctrl &= ~HD44780_DISPLAYON;
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}
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_command(dev, HD44780_DISPLAYCONTROL | dev->ctrl);
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}
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void hd44780_cursor(hd44780_t *dev, hd44780_state_t state)
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{
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if (state == HD44780_ON) {
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dev->ctrl |= HD44780_CURSORON;
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}
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else {
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dev->ctrl &= ~HD44780_CURSORON;
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}
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_command(dev, HD44780_DISPLAYCONTROL | dev->ctrl);
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}
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void hd44780_blink(hd44780_t *dev, hd44780_state_t state)
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{
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if (state == HD44780_ON) {
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dev->ctrl |= HD44780_BLINKON;
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}
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else {
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dev->ctrl &= ~HD44780_BLINKON;
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}
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_command(dev, HD44780_DISPLAYCONTROL | dev->ctrl);
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}
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void hd44780_scroll_left(const hd44780_t *dev)
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{
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_command(dev, HD44780_CURSORSHIFT | HD44780_DISPLAYMOVE | HD44780_MOVELEFT);
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}
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void hd44780_scroll_right(const hd44780_t *dev) {
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_command(dev, HD44780_CURSORSHIFT | HD44780_DISPLAYMOVE | HD44780_MOVERIGHT);
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}
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void hd44780_left2right(hd44780_t *dev)
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{
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dev->mode |= HD44780_ENTRYLEFT;
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_command(dev, HD44780_ENTRYMODESET | dev->mode);
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}
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void hd44780_right2left(hd44780_t *dev)
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{
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dev->mode &= ~HD44780_ENTRYLEFT;
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_command(dev, HD44780_ENTRYMODESET | dev->mode);
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}
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void hd44780_autoscroll(hd44780_t *dev, hd44780_state_t state)
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{
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if (state == HD44780_ON) {
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dev->mode |= HD44780_ENTRYSHIFTINCREMENT;
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}
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else {
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dev->mode &= ~HD44780_ENTRYSHIFTINCREMENT;
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}
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_command(dev, HD44780_ENTRYMODESET | dev->mode);
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}
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void hd44780_create_char(const hd44780_t *dev, uint8_t location, uint8_t charmap[])
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{
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location &= 0x7; /* 8 locations (0-7) possible */
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_command(dev, HD44780_SETCGRAMADDR | (location << 3));
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for (unsigned i = 0; i < HD44780_CGRAM_SIZE; ++i) {
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hd44780_write(dev, charmap[i]);
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}
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}
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void hd44780_write(const hd44780_t *dev, uint8_t value)
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{
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_send(dev, value, HD44780_ON);
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}
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void hd44780_print(const hd44780_t *dev, const char *data )
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{
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while (*data != '\0') {
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hd44780_write(dev, *data++);
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}
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}
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