Displaying Malaysia Covid data on I2C LCD using Raspberry Pi

I2C_LCD_driver.py

# -*- coding: utf-8 -*-

# i2c bus (0 — original Pi, 1 — Rev 2 Pi)
I2CBUS = 1

# LCD Address
ADDRESS = 0x27

import smbus
from time import sleep

class i2c_device:
    def __init__(self, addr, port=I2CBUS):
        self.addr = addr
        self.bus = smbus.SMBus(port)

    # Write a single command
    def write_cmd(self, cmd):
        self.bus.write_byte(self.addr, cmd)
        sleep(0.0001)

    # Write a command and argument
    def write_cmd_arg(self, cmd, data):
        self.bus.write_byte_data(self.addr, cmd, data)
        sleep(0.0001)

    # Write a block of data
    def write_block_data(self, cmd, data):
        self.bus.write_block_data(self.addr, cmd, data)
        sleep(0.0001)

    # Read a single byte
    def read(self):
        return self.bus.read_byte(self.addr)

    # Read
    def read_data(self, cmd):
        return self.bus.read_byte_data(self.addr, cmd)

    # Read a block of data
    def read_block_data(self, cmd):
        return self.bus.read_block_data(self.addr, cmd)

# commands
LCD_CLEARDISPLAY = 0x01
LCD_RETURNHOME = 0x02
LCD_ENTRYMODESET = 0x04
LCD_DISPLAYCONTROL = 0x08
LCD_CURSORSHIFT = 0x10
LCD_FUNCTIONSET = 0x20
LCD_SETCGRAMADDR = 0x40
LCD_SETDDRAMADDR = 0x80

# flags for display entry mode
LCD_ENTRYRIGHT = 0x00
LCD_ENTRYLEFT = 0x02
LCD_ENTRYSHIFTINCREMENT = 0x01
LCD_ENTRYSHIFTDECREMENT = 0x00

# flags for display on/off control
LCD_DISPLAYON = 0x04
LCD_DISPLAYOFF = 0x00
LCD_CURSORON = 0x02
LCD_CURSOROFF = 0x00
LCD_BLINKON = 0x01
LCD_BLINKOFF = 0x00

# flags for display/cursor shift
LCD_DISPLAYMOVE = 0x08
LCD_CURSORMOVE = 0x00
LCD_MOVERIGHT = 0x04
LCD_MOVELEFT = 0x00

# flags for function set
LCD_8BITMODE = 0x10
LCD_4BITMODE = 0x00
LCD_2LINE = 0x08
LCD_1LINE = 0x00
LCD_5x10DOTS = 0x04
LCD_5x8DOTS = 0x00

# flags for backlight control
LCD_BACKLIGHT = 0x08
LCD_NOBACKLIGHT = 0x00

En = 0b00000100 # Enable bit
Rw = 0b00000010 # Read/Write bit
Rs = 0b00000001 # Register select bit

class lcd:
    #initializes objects and lcd
    def __init__(self):
        self.lcd_device = i2c_device(ADDRESS)

        self.lcd_write(0x03)
        self.lcd_write(0x03)
        self.lcd_write(0x03)
        self.lcd_write(0x02)

        self.lcd_write(LCD_FUNCTIONSET | LCD_2LINE | LCD_5x8DOTS | LCD_4BITMODE)
        self.lcd_write(LCD_DISPLAYCONTROL | LCD_DISPLAYON)
        self.lcd_write(LCD_CLEARDISPLAY)
        self.lcd_write(LCD_ENTRYMODESET | LCD_ENTRYLEFT)
        sleep(0.2)

    # clocks EN to latch command
    def lcd_strobe(self, data):
        self.lcd_device.write_cmd(data | En | LCD_BACKLIGHT)
        sleep(.0005)
        self.lcd_device.write_cmd(((data & ~En) | LCD_BACKLIGHT))
        sleep(.0001)

    def lcd_write_four_bits(self, data):
        self.lcd_device.write_cmd(data | LCD_BACKLIGHT)
        self.lcd_strobe(data)

    # write a command to lcd
    def lcd_write(self, cmd, mode=0):
        self.lcd_write_four_bits(mode | (cmd & 0xF0))
        self.lcd_write_four_bits(mode | ((cmd << 4) & 0xF0))

    # write a character to lcd (or character rom) 0x09: backlight | RS=DR<
    # works!
    def lcd_write_char(self, charvalue, mode=1):
        self.lcd_write_four_bits(mode | (charvalue & 0xF0))
        self.lcd_write_four_bits(mode | ((charvalue << 4) & 0xF0))
  
    # put string function with optional char positioning
    def lcd_display_string(self, string, line=1, pos=0):
        if line == 1:
            pos_new = pos
        elif line == 2:
            pos_new = 0x40 + pos
        elif line == 3:
            pos_new = 0x14 + pos
        elif line == 4:
            pos_new = 0x54 + pos

        self.lcd_write(0x80 + pos_new)

        for char in string:
            self.lcd_write(ord(char), Rs)

    # clear lcd and set to home
    def lcd_clear(self):
        self.lcd_write(LCD_CLEARDISPLAY)
        self.lcd_write(LCD_RETURNHOME)

    # define backlight on/off (lcd.backlight(1); off= lcd.backlight(0)
    def backlight(self, state): # for state, 1 = on, 0 = off
        if state == 1:
            self.lcd_device.write_cmd(LCD_BACKLIGHT)
        elif state == 0:
            self.lcd_device.write_cmd(LCD_NOBACKLIGHT)

    # add custom characters (0 – 7)
    def lcd_load_custom_chars(self, fontdata):
        self.lcd_write(0x40);
        for char in fontdata:
            for line in char:
                self.lcd_write_char(line)

MalaysiaCovidData.py

"""
Displaying Malaysia Covid data on I2C LCD using Raspberry Pi

Tested with:
- https://my.cytron.io/p-raspberry-pi-400-keyboard-computer-us-layout?tracking=idris
- https://my.cytron.io/p-i2c-1602-serial-lcd-for-arduino-and-rpi?tracking=idris

Last modified:
- 23 July 2021
"""

import time
import requests
import I2C_LCD_driver

URL = "https://jhucoronavirus.azureedge.net/api/v1/regions/my.json"

lcd = I2C_LCD_driver.lcd()

new_case = 0
total = 0
prev_total = 0

while True:
    # Request the URL
    try:
        resp = requests.get(URL)
        #print(resp.json())
        #print()

        new_case = int(resp.json()["confirmed_cases"]["day"])
        total = resp.json()["confirmed_cases"]["all"]
        print("Malaysia new cases: {}, total: {}".format(new_case, total))
    
    except:
        print("{} Retrying...".format(resp))
    
    # Only display new data on LCD
    if total != prev_total:
        prev_total = total
        
        print("Displaying on LCD...")
        
        # Print on LCD
        lcd.lcd_display_string("Kes baru: " + str(new_case), 1, 0)
        lcd.lcd_display_string("Jumlah:  " + str(total), 2, 0)

    time.sleep(60) # Delay for 1 minute