/********************************************************************************************
*Filename      : i2c_lcd.cpp
*Description   : test iic 1602 lcd
*Author        : Alan
*Website       : www.osoyoo.com
*Update        : 2017/07/03->2019/5/21 cpp update
********************************************************************************************/
#include <iostream>
#include <wiringPi.h>
#include <wiringPiI2C.h>
#include <cstring>
using namespace std;

int LCDAddr = 0x27;//IIc LCD address
int BLEN = 1;//1--open backlight.0--close backlight
int fd;//linux file descriptor

//writ a word(16 bits) to LCD
void write_word(int data){
    int temp = data;
    if ( BLEN == 1 )
        temp |= 0x08;
    else
        temp &= 0xF7;
    wiringPiI2CWrite(fd, temp);
}

//send command to lcd
void send_command(int comm){
    int buf;
    // Send bit7-4 firstly
    buf = comm & 0xF0;
    buf |= 0x04;            // RS = 0, RW = 0, EN = 1
    write_word(buf);
    delay(2);
    buf &= 0xFB;            // Make EN = 0
    write_word(buf);

    // Send bit3-0 secondly
    buf = (comm & 0x0F) << 4;
    buf |= 0x04;            // RS = 0, RW = 0, EN = 1
    write_word(buf);
    delay(2);
    buf &= 0xFB;            // Make EN = 0
    write_word(buf);
}

//send data to lcd
void send_data(int data){
    int buf;
    // Send bit7-4 firstly
    buf = data & 0xF0;
    buf |= 0x05;            // RS = 1, RW = 0, EN = 1
    write_word(buf);
    delay(2);
    buf &= 0xFB;            // Make EN = 0
    write_word(buf);

    // Send bit3-0 secondly
    buf = (data & 0x0F) << 4;
    buf |= 0x05;            // RS = 1, RW = 0, EN = 1
    write_word(buf);
    delay(2);
    buf &= 0xFB;            // Make EN = 0
    write_word(buf);
}

//initialize the lcd
void init(){
    send_command(0x33); // Must initialize to 8-line mode at first
    delay(5);
    send_command(0x32); // Then initialize to 4-line mode
    delay(5);
    send_command(0x28); // 2 Lines & 5*7 dots
    delay(5);
    send_command(0x0C); // Enable display without cursor
    delay(5);
    send_command(0x01); // Clear Screen
    wiringPiI2CWrite(fd, 0x08);
}

//clear screen
void clear(){
    send_command(0x01); //clear Screen
}

//Print the message on the lcd
void write(int x, int y, char* data){
    int addr, i;
    int tmp;
    if (x < 0)  x = 0;
    if (x > 15) x = 15;
    if (y < 0)  y = 0;
    if (y > 1)  y = 1;

    // Move cursor
    addr = 0x80 + 0x40 * y + x;
    send_command(addr);

    //tmp = strlen(data);
    for (; *data != '\0'; data++){
        send_data(*data);
    }
}

//Print the message on the lcd
void writekana(int x, int y, char* data){
    int addr, i;
    int tmp;
    if (x < 0)  x = 0;
    if (x > 15) x = 15;
    if (y < 0)  y = 0;
    if (y > 1)  y = 1;

    // Move cursor
    addr = 0x80 + 0x40 * y + x;
    send_command(addr);

    //tmp = strlen(data);
    for (; *data != '\0'; data++){
        *data |= 0x80;
        send_data(*data);
    }
}

void print_info()
{
    cout << "\n";
    cout << "|***************************|\n";
    cout << "|    I2C 1602 LCD test      |\n";
    cout << "| --------------------------|\n";
    cout << "| | LCD |            | Pi   |\n";
    cout << "| --------------------------|\n";
    cout << "| | GND | connect to | GND  |\n";
    cout << "| | VCC | connect to | 5V   |\n";
    cout << "| | SDA | connect to | SDA.1|\n";
    cout << "| | SCL | connect to | SCL.1|\n";
    cout << "| --------------------------|\n";
    cout << "|                     OSOYOO|\n";
    cout << "|***************************|\n";
    cout << "Program is running...\n";
    cout << "Press Ctrl+C to end the program\n";
}
int main(){
    //init I2C
    char sdata[100];
    fd = wiringPiI2CSetup(LCDAddr);
    init();
    print_info();
    strcpy(sdata,"6@6E");
    writekana(0, 0, sdata);
    strcpy(sdata,"VRY6E");
    writekana(0, 1, sdata);
    delay(3000);
    clear();
    while(1){
        strcpy(sdata,"This is Lesson13"); 
        write(0,0,sdata);
        strcpy(sdata,"IIC LCD Test");
        write(0,1,sdata);
        delay(1000);
    }
    return 0;
}