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Driver for HD44780 LCDs (#246)

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Driver for HD44780 LCDs connected directly to GPIO / to I2C by PCF8574-like GPIO expanders (#246)
This commit is contained in:
Ruslan V. Uss 2016-10-26 19:21:55 +06:00 committed by sheinz
parent 698f7424eb
commit 574f944fbb
9 changed files with 457 additions and 0 deletions
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6
examples/hd44780_lcd/Makefile Normal file
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PROGRAM = hd44780_lcd
EXTRA_COMPONENTS = extras/hd44780
HD44780_I2C = 0
include ../../common.mk

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examples/hd44780_lcd/main.c Normal file
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/*
* Example of using HD44780 driver with LCD
* connected directly to GPIO pins
*
* Part of esp-open-rtos
* Copyright (C) 2016 Ruslan V. Uss <unclerus@gmail.com>
* BSD Licensed as described in the file LICENSE
*/
#include <esp/uart.h>
#include <espressif/esp_common.h>
#include <stdio.h>
#include <hd44780/hd44780.h>
static const uint8_t char_data[] = {
0x04, 0x0e, 0x0e, 0x0e, 0x1f, 0x00, 0x04, 0x00,
0x1f, 0x11, 0x0a, 0x04, 0x0a, 0x11, 0x1f, 0x00
};
void user_init(void)
{
uart_set_baud(0, 115200);
printf("SDK version:%s\n", sdk_system_get_sdk_version());
hd44780_t lcd = {
.font = HD44780_FONT_5X8,
.lines = 2,
.pins = {
.rs = 5,
.e = 4,
.d4 = 0,
.d5 = 2,
.d6 = 14,
.d7 = 12,
.bl = HD44780_NOT_USED
}
};
hd44780_init(&lcd);
hd44780_upload_character(&lcd, 0, char_data);
hd44780_upload_character(&lcd, 1, char_data + 8);
hd44780_gotoxy(&lcd, 0, 0);
hd44780_puts(&lcd, "\x08 Hello world!");
hd44780_gotoxy(&lcd, 0, 1);
hd44780_puts(&lcd, "\x09 ");
char time[16];
while (true)
{
hd44780_gotoxy(&lcd, 2, 1);
snprintf(time, 7, "%u ", sdk_system_get_time() / 1000000);
time[sizeof(time) - 1] = 0;
hd44780_puts(&lcd, time);
for (uint32_t i = 0; i < 1000; i++)
sdk_os_delay_us(1000);
}
}

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6
examples/i2c_lcd_test/Makefile Normal file
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PROGRAM = i2c_lcd_test
EXTRA_COMPONENTS = extras/i2c extras/pcf8574 extras/hd44780
HD44780_I2C = 1
include ../../common.mk

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examples/i2c_lcd_test/main.c Normal file
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/*
* Example of using driver for text LCD
* connected to I2C by PCF8574
*
* Part of esp-open-rtos
* Copyright (C) 2016 Ruslan V. Uss <unclerus@gmail.com>
* BSD Licensed as described in the file LICENSE
*/
#include <esp/uart.h>
#include <espressif/esp_common.h>
#include <i2c/i2c.h>
#include <stdio.h>
#include <hd44780/hd44780.h>
#define SCL_PIN 5
#define SDA_PIN 4
#define ADDR 0x27
static const uint8_t char_data[] = {
0x04, 0x0e, 0x0e, 0x0e, 0x1f, 0x00, 0x04, 0x00,
0x1f, 0x11, 0x0a, 0x04, 0x0a, 0x11, 0x1f, 0x00
};
void user_init(void)
{
uart_set_baud(0, 115200);
printf("SDK version:%s\n", sdk_system_get_sdk_version());
i2c_init(SCL_PIN, SDA_PIN);
hd44780_t lcd = {
.addr = ADDR,
.font = HD44780_FONT_5X8,
.lines = 2,
.pins = {
.rs = 0,
.e = 2,
.d4 = 4,
.d5 = 5,
.d6 = 6,
.d7 = 7,
.bl = 3
},
.backlight = true
};
hd44780_init(&lcd);
hd44780_upload_character(&lcd, 0, char_data);
hd44780_upload_character(&lcd, 1, char_data + 8);
hd44780_gotoxy(&lcd, 0, 0);
hd44780_puts(&lcd, "\x08 Hello world!");
hd44780_gotoxy(&lcd, 0, 1);
hd44780_puts(&lcd, "\x09 ");
char time[16];
while (true)
{
hd44780_gotoxy(&lcd, 2, 1);
snprintf(time, 7, "%u ", sdk_system_get_time() / 1000000);
time[sizeof(time) - 1] = 0;
hd44780_puts(&lcd, time);
for (uint32_t i = 0; i < 1000; i++)
sdk_os_delay_us(1000);
}
}

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extras/hd44780/component.mk Normal file
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INC_DIRS += $(hd44780_ROOT)..
hd44780_SRC_DIR = $(hd44780_ROOT)
HD44780_I2C ?= 1
hd44780_CFLAGS = -DHD44780_I2C=${HD44780_I2C} $(CFLAGS)
$(eval $(call component_compile_rules,hd44780))

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extras/hd44780/hd44780.c Normal file
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#include "hd44780.h"
#if (HD44780_I2C)
#include <pcf8574/pcf8574.h>
#else
#include <esp/gpio.h>
#endif
#include <espressif/esp_common.h>
#define MS 1000
#define DELAY_CMD_LONG (3 * MS) // >1.53ms according to datasheet
#define DELAY_CMD_SHORT (60) // >39us according to datasheet
#define DELAY_TOGGLE (10)
#define DELAY_INIT (5 * MS)
#define CMD_CLEAR 0x01
#define CMD_RETURN_HOME 0x02
#define CMD_ENTRY_MODE 0x04
#define CMD_DISPLAY_CTRL 0x08
#define CMD_SHIFT 0x10
#define CMD_FUNC_SET 0x20
#define CMD_CGRAM_ADDR 0x40
#define CMD_DDRAM_ADDR 0x80
// CMD_ENTRY_MODE
#define ARG_EM_INCREMENT (1 << 1)
#define ARG_EM_SHIFT (1)
// CMD_DISPLAY_CTRL
#define ARG_DC_DISPLAY_ON (1 << 2)
#define ARG_DC_CURSOR_ON (1 << 1)
#define ARG_DC_CURSOR_BLINK (1)
// CMD_FUNC_SET
#define ARG_FS_8_BIT (1 << 4)
#define ARG_FS_2_LINES (1 << 3)
#define ARG_FS_FONT_5X10 (1 << 2)
#if (HD44780_I2C)
#define init_delay() do { sdk_os_delay_us(DELAY_INIT); } while (0)
#define short_delay()
#define long_delay() do { sdk_os_delay_us(DELAY_CMD_LONG); } while (0)
#else
#define init_delay() do { sdk_os_delay_us(DELAY_INIT); } while (0)
#define short_delay() do { sdk_os_delay_us(DELAY_CMD_SHORT); } while (0)
#define long_delay() do { sdk_os_delay_us(DELAY_CMD_LONG); } while (0)
#define toggle_delay() do { sdk_os_delay_us(DELAY_TOGGLE); } while (0)
#endif
static const uint8_t line_addr[] = { 0x00, 0x40, 0x14, 0x54 };
static void write_nibble(const hd44780_t *lcd, uint8_t b, bool rs)
{
#if (HD44780_I2C)
uint8_t data = (((b >> 3) & 1) << lcd->pins.d7)
| (((b >> 2) & 1) << lcd->pins.d6)
| (((b >> 1) & 1) << lcd->pins.d5)
| ((b & 1) << lcd->pins.d4)
| (rs ? 1 << lcd->pins.rs : 0)
| (lcd->backlight ? 1 << lcd->pins.bl : 0);
pcf8574_port_write(lcd->addr, data | (1 << lcd->pins.e));
pcf8574_port_write(lcd->addr, data);
#else
gpio_write(lcd->pins.d7, (b >> 3) & 1);
gpio_write(lcd->pins.d6, (b >> 2) & 1);
gpio_write(lcd->pins.d5, (b >> 1) & 1);
gpio_write(lcd->pins.d4, b & 1);
gpio_write(lcd->pins.rs, rs);
gpio_write(lcd->pins.e, true);
toggle_delay();
gpio_write(lcd->pins.e, false);
#endif
}
static void write_byte(const hd44780_t *lcd, uint8_t b, bool rs)
{
write_nibble(lcd, b >> 4, rs);
write_nibble(lcd, b, rs);
}
void hd44780_init(const hd44780_t *lcd)
{
#if (!HD44780_I2C)
gpio_enable(lcd->pins.rs, GPIO_OUTPUT);
gpio_enable(lcd->pins.e, GPIO_OUTPUT);
gpio_enable(lcd->pins.d4, GPIO_OUTPUT);
gpio_enable(lcd->pins.d5, GPIO_OUTPUT);
gpio_enable(lcd->pins.d6, GPIO_OUTPUT);
gpio_enable(lcd->pins.d7, GPIO_OUTPUT);
if (lcd->pins.bl != HD44780_NOT_USED)
gpio_enable(lcd->pins.bl, GPIO_OUTPUT);
#endif
// switch to 4 bit mode
for (uint8_t i = 0; i < 3; i ++)
{
write_nibble(lcd, (CMD_FUNC_SET | ARG_FS_8_BIT) >> 4, false);
init_delay();
}
write_nibble(lcd, CMD_FUNC_SET >> 4, false);
// Specify the number of display lines and character font
write_byte(lcd,
CMD_FUNC_SET
| (lcd->lines > 1 ? ARG_FS_2_LINES : 0)
| (lcd->font == HD44780_FONT_5X10 ? ARG_FS_FONT_5X10 : 0),
false);
short_delay();
// Display off
hd44780_control(lcd, false, false, false);
// Clear
hd44780_clear(lcd);
// Entry mode set
write_byte(lcd, CMD_ENTRY_MODE | ARG_EM_INCREMENT, false);
short_delay();
// Display on
hd44780_control(lcd, true, false, false);
}
void hd44780_control(const hd44780_t *lcd, bool on, bool cursor, bool cursor_blink)
{
write_byte(lcd,
CMD_DISPLAY_CTRL
| (on ? ARG_DC_DISPLAY_ON : 0)
| (cursor ? ARG_DC_CURSOR_ON : 0)
| (cursor_blink ? ARG_DC_CURSOR_BLINK : 0),
false);
short_delay();
}
void hd44780_clear(const hd44780_t *lcd)
{
write_byte(lcd, CMD_CLEAR, false);
long_delay();
}
void hd44780_gotoxy(const hd44780_t *lcd, uint8_t col, uint8_t line)
{
if (line >= lcd->lines) line = lcd->lines - 1;
uint8_t addr = line < sizeof(line_addr) ? line_addr[line] : 0;
write_byte(lcd, CMD_DDRAM_ADDR + addr + col, false);
short_delay();
}
void hd44780_putc(const hd44780_t *lcd, char c)
{
write_byte(lcd, c, true);
short_delay();
}
void hd44780_puts(const hd44780_t *lcd, const char *s)
{
while (*s)
{
hd44780_putc(lcd, *s);
s++;
}
}
void hd44780_set_backlight(hd44780_t *lcd, bool on)
{
if (lcd->pins.bl == HD44780_NOT_USED)
return;
#if (HD44780_I2C)
pcf8574_gpio_write(lcd->addr, lcd->pins.bl, on);
#else
gpio_write(lcd->pins.bl, on);
#endif
lcd->backlight = on;
}
void hd44780_upload_character(const hd44780_t *lcd, uint8_t num, const uint8_t *data)
{
if (num > 7) return;
uint8_t bytes = lcd->font == HD44780_FONT_5X8 ? 8 : 10;
write_byte(lcd, CMD_CGRAM_ADDR + num * bytes, false);
short_delay();
for (uint8_t i = 0; i < bytes; i ++)
{
write_byte(lcd, data[i], true);
short_delay();
}
hd44780_gotoxy(lcd, 0, 0);
}

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/*
* Driver for LCD text displays on LCD connected to I2C by PCF8574
*
* Part of esp-open-rtos
* Copyright (C) 2016 Ruslan V. Uss <unclerus@gmail.com>
* BSD Licensed as described in the file LICENSE
*/
#ifndef _EXTRAS_HD44780_H_
#define _EXTRAS_HD44780_H_
#include <stdint.h>
#include <stdbool.h>
#ifndef HD44780_I2C
#define HD44780_I2C 0
#endif
#ifdef __cplusplus
extern "C" {
#endif
#define HD44780_NOT_USED 0xff
/**
* LCD font type. Please refer to the datasheet
* of your module.
*/
typedef enum
{
HD44780_FONT_5X8 = 0,
HD44780_FONT_5X10
} hd44780_font_t;
/**
* LCD descriptor. Fill it before use.
*/
typedef struct
{
uint8_t addr; //!< PCF8574 address (0b0100<A2><A1><A0>)
struct
{
uint8_t rs; //!< gpio/register bit used for RS pin
uint8_t e; //!< register bit used for E pin
uint8_t d4; //!< register bit used for D4 pin
uint8_t d5; //!< register bit used for D5 pin
uint8_t d6; //!< register bit used for D5 pin
uint8_t d7; //!< register bit used for D5 pin
uint8_t bl; //!< register bit used for backlight, 0xFF if not used
} pins;
hd44780_font_t font; //!< LCD Font type
uint8_t lines; //!< Number of lines for LCD. Many 16x1 LCD has two lines (like 8x2)
bool backlight; //!< Current backlight state
} hd44780_t;
/**
* Init LCD. Set poition to (0, 0)
* \param lcd Pointer to the LCD descriptor
*/
void hd44780_init(const hd44780_t *lcd);
/**
* On/off LCD, show/hide cursor, set cursor blink
* \param lcd Pointer to the LCD descriptor
*/
void hd44780_control(const hd44780_t *lcd, bool on, bool cursor, bool cursor_blink);
/**
* Clear LCD memory and move char position to (0, 0)
* \param lcd Pointer to the LCD descriptor
*/
void hd44780_clear(const hd44780_t *lcd);
/**
* Set current char position
* \param lcd Pointer to the LCD descriptor
* \param col Column
* \param line Line
*/
void hd44780_gotoxy(const hd44780_t *lcd, uint8_t col, uint8_t line);
/**
* Print character
* \param lcd Pointer to the LCD descriptor
* \param c Character
*/
void hd44780_putc(const hd44780_t *lcd, char c);
/**
* Print string
* \param lcd Pointer to the LCD descriptor
* \param s String
*/
void hd44780_puts(const hd44780_t *lcd, const char *s);
/**
* Switch backlight
* \param lcd Pointer to the LCD descriptor
* \param on Turn backlight on if true
*/
void hd44780_set_backlight(hd44780_t *lcd, bool on);
/**
* Upload character data to the CGRAM.
* Current position will be set to (0, 0) after uploading
* \param lcd Pointer to the LCD descriptor
* \param num Character number (0..7)
* \param data Character data: 8 or 10 bytes depending on the font
*/
void hd44780_upload_character(const hd44780_t *lcd, uint8_t num, const uint8_t *data);
#ifdef __cplusplus
}
#endif
#endif /* _EXTRAS_HD44780_H_ */