LCD_Shield_Python/Libs/LCD_Shield/__init__.py

"""
Author:     Tobias Müller
Date:       30.06.2023
Version:    0.5

This file contains classes for LCD, Button and Led control.
"""

##############################                Modules                 ##############################

from time import sleep_us
from machine import Pin, PWM, I2C
import re

##############################                  Code                  ##############################

class LCD:

    ##############################           Attributes           ##############################

    __lcd_setting = {"CONTROL_BYTE": 0x80,          # Set Continue Bit
                     "LCD_PARA_FUNC1": 0x3A,        # Function Set 1 (8 Bit, RE = 1, IS = 0)
                     "LCD_PARA_EXT_FUNC": 0x09,     # Extended Function
                     "LCD_PARA_ENTRY_MODE": 0x06,   # Bottom View
                     "LCD_PARA_BIAS_SET": 0x1E,     # Bias Setting
                     "LCD_PARA_FUNC2": 0x39,        # Function Set 2 (8 Bit, RE = 0, IS = 1)
                     "LCD_PARA_INT_OSC": 0x1B,      # Internal OSC (BS0 = 1, Bias = 1/6)
                     "LCD_PARA_FOL_CON": 0x6E,      # Follower Control (Devider on, Set Value)
                     "LCD_PARA_POW_CON": 0x56,      # Power Control (Booster on, Set Contrast)
                     "LCD_PARA_CONTRAST": 0x7A,     # Set Contrast
                     "LCD_PARA_FUNC3": 0x38,        # Function Set 3 (8 Bit, RE = 0, IS = 0)
                     "LCD_PARA_DIS_CON": 0x0C,      # Display on/off Control (Cursor off, Blink off)
                     "LCD_PARA_CLR_DIS": 0x01}      # Clear Display

    __lcd_control = {"CONTROL_BYTE": 0x80,          # Set Continue Bit
                     "CONTROL_BYTE_DCB": 0x40,      # Data/Command Selection Bit set
                     "LCD_PARA_CLR_DIS": 0x01,      # Clear Display
                     "LCD_PARA_DIS_ROW1": 0x80,     # Display Row 1
                     "LCD_PARA_DIS_ROW2": 0xA0,     # Display Row 2
                     "LCD_PARA_DIS_ROW3": 0xC0,     # Display Row 3
                     "LCD_PARA_DIS_ROW4": 0xE0,     # Display Row 4
                     "LCD_PARA_DIS_COLUMN": 0x0A}   # Columns per Display Row

    __i2c_ports = {"I2C0": {"SDA_PINS": [0, 4 ,8 ,12 ,16 ,20],
                            "SCL_PINS": [1, 5, 9, 13, 17, 21]},
                   "I2C1": {"SDA_PINS": [2, 6, 10, 14, 18, 26],
                            "SCL_PINS": [3, 7, 11, 15, 19, 27]}}
    
    __i2c_frequencies = {"STANDARD_MODE": 100000,
                         "FAST_MODE": 400000,
                         "FAST_MODE_PLUS": 1000000}

    __i2c_address = 0x3c

    ##############################           Constructor          ##############################

    def __init__(self,
                 i2c_sda_pin: int|str = 2,
                 i2c_scl_pin: int|str = 3,
                 i2c_frequency: int|str = 400000,
                 lcd_backlight_pin: int|str = 28,
                 lcd_brightness: int = 100):

        # Check and store input values
        self.__I2C_Bus, self.__I2C_SDA_Pin, self.__I2C_SCL_Pin = self.__check_i2c_ports(i2c_sda_pin,
                                                                                        i2c_scl_pin)
        self.__i2c_frequency = self.__check_i2c_speed(i2c_frequency)
        self.__lcd_backlight_pin = self.__check_lcd_backlight_pin(lcd_backlight_pin)
        self.__lcd_brightness = self.__check_lcd_brightness(lcd_brightness)

        # init i2c and backlight
        self.__init_i2c()
        self.__init_backlight_pwm()

    ##############################           Properties           ##############################

    @property
    def lcd_brightness(self):
        return self.__lcd_brightness

    @lcd_brightness.setter
    def lcd_brightness(self, lcd_brightness: int):
        self.__lcd_brightness = self.__check_lcd_brightness(lcd_brightness)
        self.__backlight_pwm.duty_u16(round(65635 * (lcd_brightness / 100)))

    ##############################         Methods private        ##############################

    @staticmethod
    def __reset_pin(pin):
        Pin(pin, Pin.IN, None)

    @staticmethod
    def __check_lcd_brightness(lcd_brightness):
        if not isinstance(lcd_brightness, int):
            raise ValueError(f"Value \"{lcd_brightness}\" of \"lcd_brightness\" is not type \"int\"!")
        elif lcd_brightness < 0 or lcd_brightness > 100:
            raise ValueError(f"Value \"{lcd_brightness}\" of \"lcd_brightness\" is out of range!")
        else:
            return lcd_brightness

    @staticmethod
    def __check_lcd_backlight_pin(lcd_backlight_pin):
        if not isinstance(lcd_backlight_pin, int) and not isinstance(lcd_backlight_pin, str):
            raise ValueError(f"Value \"{lcd_backlight_pin}\" of \"lcd_backlight_pin\" is not type" +
                             " \"int\" or \"str\"!")
        elif isinstance(lcd_backlight_pin, str) and not re.match(r"^GP\d\d?$",lcd_backlight_pin):
            raise ValueError(f"String value \"{lcd_backlight_pin}\" of \"lcd_backlight_pin\" has" +
                             "  wrong format!")
        else:
            return lcd_backlight_pin

    def __check_i2c_ports(self, i2c_sda_pin, i2c_scl_pin):
        if not isinstance(i2c_sda_pin, int) and not isinstance(i2c_sda_pin, str):
            raise ValueError(f"Value \"{i2c_sda_pin}\" of \"i2c_sda_pin\" is not type \"int\"" +
                             " or \"str\"!")
        elif not isinstance(i2c_scl_pin, int) and not isinstance(i2c_scl_pin, str):
            raise ValueError(f"Value \"{i2c_scl_pin}\" of \"i2c_scl_pin\" is not type \"int\"" +
                             " or \"str\"!")
        elif isinstance(i2c_sda_pin, str) and not re.match(r"^GP\d\d?$",i2c_sda_pin):
            raise ValueError(f"String value \"{i2c_sda_pin}\" of \"i2c_sda_pin\" has wrong format!")
        elif isinstance(i2c_scl_pin, str) and not re.match(r"^GP\d\d?$",i2c_scl_pin):
            raise ValueError(f"String value \"{i2c_scl_pin}\" of \"i2c_scl_pin\" has wrong format!")
        elif ((isinstance(i2c_sda_pin, int) and
               not i2c_sda_pin in self.__i2c_ports["I2C0"]["SDA_PINS"] and
               not i2c_sda_pin in self.__i2c_ports["I2C1"]["SDA_PINS"]) or
              (isinstance(i2c_sda_pin, str) and
               not int(i2c_sda_pin[2:]) in self.__i2c_ports["I2C0"]["SDA_PINS"] and
               not int(i2c_sda_pin[2:]) in self.__i2c_ports["I2C1"]["SDA_PINS"])):
            raise ValueError(f"Value \"{i2c_sda_pin}\" of \"i2c_sda_pin\" is not an I2C SDA-Pin!")
        elif ((isinstance(i2c_scl_pin, int) and
               not i2c_scl_pin in self.__i2c_ports["I2C0"]["SCL_PINS"] and
               not i2c_scl_pin in self.__i2c_ports["I2C1"]["SCL_PINS"]) or
              (isinstance(i2c_scl_pin, str) and
               not int(i2c_scl_pin[2:]) in self.__i2c_ports["I2C0"]["SCL_PINS"] and
               not int(i2c_scl_pin[2:]) in self.__i2c_ports["I2C1"]["SCL_PINS"])):
            raise ValueError(f"Value \"{i2c_scl_pin}\" of \"i2c_scl_pin\" is not an I2C SCL-Pin!")
        elif ((((isinstance(i2c_sda_pin, int) and 
                 i2c_sda_pin in self.__i2c_ports["I2C0"]["SDA_PINS"]) or
                (isinstance(i2c_sda_pin, str) and 
                 int(i2c_sda_pin[2:]) in self.__i2c_ports["I2C0"]["SDA_PINS"])) and not
               ((isinstance(i2c_scl_pin, int) and 
                 i2c_scl_pin in self.__i2c_ports["I2C0"]["SCL_PINS"]) or
                (isinstance(i2c_scl_pin, str) and 
                 int(i2c_scl_pin[2:]) in self.__i2c_ports["I2C0"]["SCL_PINS"]))) or
              (((isinstance(i2c_sda_pin, int) and 
                 i2c_sda_pin in self.__i2c_ports["I2C1"]["SDA_PINS"]) or
                (isinstance(i2c_sda_pin, str) and 
                 int(i2c_sda_pin[2:]) in self.__i2c_ports["I2C1"]["SDA_PINS"])) and not
               ((isinstance(i2c_scl_pin, int) and 
                 i2c_scl_pin in self.__i2c_ports["I2C1"]["SCL_PINS"]) or
                (isinstance(i2c_scl_pin, str) and 
                 int(i2c_scl_pin[2:]) in self.__i2c_ports["I2C1"]["SCL_PINS"])))):
            raise ValueError(f"Value \"{i2c_scl_pin}\" of \"i2c_scl_pin\" and " +
                             f"Value \"{i2c_sda_pin}\" of \"i2c_sda_pin\" " +
                             "are not part of the same I2C Bus!")
        else:
            if ((isinstance(i2c_sda_pin, int) and 
                 i2c_sda_pin in self.__i2c_ports["I2C0"]["SDA_PINS"]) or
                (isinstance(i2c_sda_pin, str) and 
                 int(i2c_sda_pin[2:]) in self.__i2c_ports["I2C0"]["SDA_PINS"])):
                return 0, i2c_sda_pin, i2c_scl_pin
            else:
                return 1, i2c_sda_pin, i2c_scl_pin

    def __check_i2c_speed(self, i2c_frequency):
        if not isinstance(i2c_frequency, int) and not isinstance(i2c_frequency, str):
            raise ValueError(f"Value \"{i2c_frequency}\" of \"i2c_frequency\" is not type \"int\"" +
                             " or \"str\"!")
        elif (isinstance(i2c_frequency, int) and not i2c_frequency in self.__i2c_frequencies.values() or
              isinstance(i2c_frequency, str) and not i2c_frequency in self.__i2c_frequencies.keys()):
            raise ValueError(f"Value \"{i2c_frequency}\" of \"i2c_frequency\" is not supported!")
        else:
            return i2c_frequency
    

    def __init_i2c(self):
        self.__i2c = I2C(self.__I2C_Bus,
                         sda=Pin(self.__I2C_SDA_Pin),
                         scl=Pin(self.__I2C_SCL_Pin),
                         freq=(self.__i2c_frequency if isinstance(self.__i2c_frequency, int) else
                               self.__i2c_frequencies[self.__i2c_frequency]))
        self.__i2c.writeto(self.__i2c_address, bytes(self.__lcd_setting.values()))

    def __deinit_i2c(self):
        self.__reset_pin(self.__I2C_SCL_Pin)
        self.__reset_pin(self.__I2C_SDA_Pin)

    def __init_backlight_pwm(self):
        self.__backlight_pwm = PWM(Pin(self.__lcd_backlight_pin))
        self.__backlight_pwm.freq(1000)
        self.__backlight_pwm.duty_u16(round(65635 * (self.lcd_brightness / 100)))

    def __deinit_backlight_pwm(self):
        self.__backlight_pwm.deinit()
        self.__reset_pin(self.__lcd_backlight_pin)

    ##############################         Methods public         ##############################

    def change_i2c_port(self, i2c_sda_pin: int|str, i2c_scl_pin: int|str):    
        self.__I2C_Bus, i2c_sda_pin, i2c_scl_pin = self.__check_i2c_ports(i2c_sda_pin, i2c_scl_pin)
        self.__deinit_i2c()
        self.__I2C_SCL_Pin = i2c_scl_pin
        self.__I2C_SDA_Pin = i2c_sda_pin
        self.__init_i2c()

    def print(self, text: str, **keywords):
        if not isinstance(text, str):
            raise ValueError(f"Value \"{text}\" of \"text\" is not type \"str\"!")
        elif len(keywords) == 0:
            self.clear()
            buffer = [self.__lcd_control["CONTROL_BYTE"]]
            buffer.append(self.__lcd_control["LCD_PARA_DIS_ROW1"])
            buffer.append(self.__lcd_control["CONTROL_BYTE_DCB"])
            for i in range(0, self.__lcd_control["LCD_PARA_DIS_COLUMN"] if
                           len(text) > self.__lcd_control["LCD_PARA_DIS_COLUMN"] else len(text)):
                buffer.append(ord(text[i]))
            print(bytes(buffer))
            self.__i2c.writeto(self.__i2c_address, bytes(buffer))

    def clear(self):
        buffer = [self.__lcd_control["CONTROL_BYTE"], self.__lcd_control["LCD_PARA_CLR_DIS"]]
        self.__i2c.writeto(self.__i2c_address, bytes(buffer))

if __name__ == "__main__":
    lcd = LCD(i2c_scl_pin="GP3", i2c_sda_pin=2, i2c_frequency=100000)
    lcd.print("Hallo")