More on LCD class

This commit is contained in:
Martin Brodbeck 2022-05-30 21:33:48 +02:00
parent b084a2df64
commit 0a48d09436
3 changed files with 114 additions and 13 deletions

View file

@ -13,12 +13,9 @@ int main() {
// Enable UART so we can print status output
stdio_init_all();
uint8_t data = 0;
int ret{0};
auto myLCD = LCD(i2c1, I2C_SDA_PIN, I2C_SCL_PIN, I2C_ADDR);
myLCD.backlight_on();
std::cout << "FINISHED!" << std::endl;
myLCD.sendString("Hallo, Welt");
myLCD.clear();
myLCD.sendString("le");
}

99
lcd.cpp
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@ -1,18 +1,104 @@
#include "lcd.h"
constexpr uint8_t SHIFT_BACKLIGHT = 3;
// commands
constexpr int LCD_CLEARDISPLAY = 0x01;
constexpr int LCD_RETURNHOME = 0x02;
constexpr int LCD_ENTRYMODESET = 0x04;
constexpr int LCD_DISPLAYCONTROL = 0x08;
constexpr int LCD_CURSORSHIFT = 0x10;
constexpr int LCD_FUNCTIONSET = 0x20;
constexpr int LCD_SETCGRAMADDR = 0x40;
constexpr int LCD_SETDDRAMADDR = 0x80;
// flags for display entry mode
constexpr int LCD_ENTRYSHIFTINCREMENT = 0x01;
constexpr int LCD_ENTRYLEFT = 0x02;
// flags for display and cursor control
constexpr int LCD_BLINKON = 0x01;
constexpr int LCD_CURSORON = 0x02;
constexpr int LCD_DISPLAYON = 0x04;
// flags for function set
constexpr int LCD_5x10DOTS = 0x04;
constexpr int LCD_2LINE = 0x08;
constexpr int LCD_8BITMODE = 0x10;
constexpr int LCD_BACKLIGHT = 0x08;
constexpr int LCD_ENABLE_BIT = 0x04;
LCD::LCD(i2c_inst_t *i2c, const uint gpio_sda, const uint gpio_scl,
const uint8_t i2c_addr, uint8_t num_cols, uint8_t num_lines)
: i2c_addr{i2c_addr}, num_cols{num_cols}, num_lines{num_lines} {
: i2c{i2c}, i2c_addr{i2c_addr}, num_cols{num_cols}, num_lines{num_lines}
{
i2c_init(i2c1, 100 * 1000);
gpio_set_function(gpio_sda, GPIO_FUNC_I2C);
gpio_set_function(gpio_scl, GPIO_FUNC_I2C);
gpio_pull_up(gpio_sda);
gpio_pull_up(gpio_scl);
sendByte(0x03, Mode::COMMAND);
sendByte(0x03, Mode::COMMAND);
sendByte(0x03, Mode::COMMAND);
sendByte(0x02, Mode::COMMAND);
sendByte(LCD_ENTRYMODESET | LCD_ENTRYLEFT, Mode::COMMAND);
sendByte(LCD_FUNCTIONSET | LCD_2LINE, Mode::COMMAND);
sendByte(LCD_DISPLAYCONTROL | LCD_DISPLAYON, Mode::COMMAND);
clear();
}
int LCD::backlight_off() {
// go to location on LCD
void LCD::setCursor(int line, int position) {
int val = (line == 0) ? 0x80 + position : 0xC0 + position;
sendByte(val, Mode::COMMAND);
}
void LCD::sendChar(char val) {
sendByte(val, Mode::CHARACTER);
}
void LCD::sendString(const std::string &str) {
for (const char &c : str) {
sendChar(c);
}
}
void LCD::clear() {
sendByte(LCD_CLEARDISPLAY, Mode::COMMAND);
}
void LCD::i2cWriteByte(uint8_t val)
{
i2c_write_blocking(i2c, i2c_addr, &val, 1, false);
}
void LCD::toggleEnable(uint8_t val)
{
// Toggle enable pin on LCD display
// We cannot do this too quickly or things don't work
constexpr uint64_t DELAY_US = 600;
sleep_us(DELAY_US);
i2cWriteByte(val | LCD_ENABLE_BIT);
sleep_us(DELAY_US);
i2cWriteByte(val & ~LCD_ENABLE_BIT);
sleep_us(DELAY_US);
}
// The display is sent a byte as two separate nibble transfers
void LCD::sendByte(uint8_t val, Mode mode)
{
uint8_t high = static_cast<int>(mode) | (val & 0xF0) | LCD_BACKLIGHT;
uint8_t low = static_cast<int>(mode) | ((val << 4) & 0xF0) | LCD_BACKLIGHT;
i2cWriteByte(high);
toggleEnable(high);
i2cWriteByte(low);
toggleEnable(low);
}
int LCD::backlight_off()
{
uint8_t data = 0;
int ret{0};
@ -21,11 +107,12 @@ int LCD::backlight_off() {
return ret;
}
int LCD::backlight_on() {
uint8_t data = 1 << SHIFT_BACKLIGHT;
int LCD::backlight_on()
{
int ret{0};
/*uint8_t data = 1 << SHIFT_BACKLIGHT;
ret = i2c_write_blocking(i2c1, i2c_addr, &data, 1, false);
ret = i2c_write_blocking(i2c1, i2c_addr, &data, 1, false);*/
return ret;
}

19
lcd.h
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@ -1,17 +1,34 @@
#ifndef LCD_H
#define LCD_H
#include <string>
#include "hardware/i2c.h"
#include "pico/stdlib.h"
class LCD {
enum class Mode
{
COMMAND,
CHARACTER
};
class LCD
{
public:
LCD(i2c_inst_t *i2c, const uint gpio_sda, const uint gpio_scl,
const uint8_t i2c_addr, uint8_t num_cols = 16, uint8_t num_lines = 2);
int backlight_off();
int backlight_on();
void sendString(const std::string &str);
void setCursor(int line, int position);
void clear();
private:
void sendByte(uint8_t val, Mode mode);
void toggleEnable(uint8_t val);
void i2cWriteByte(uint8_t val);
void sendChar(char val);
i2c_inst_t *i2c;
uint8_t i2c_addr;
uint8_t num_cols;
uint8_t num_lines;