import time

time.sleep(0.2)
print('Welcome to Pingpong!')

main.py

diagram.json

"""
# Button.py - Object-Oriented implementation of a Button
# Also added a simple implementation of a single analog Joystick
# Author: Arijit Sengupta
"""

from machine import Pin, ADC
import time
from Log import *

class Button:
    """
    A simple Button class
    Create the button using Button(pinnumber, name, handler)
    handler is typically self, and create two methods buttonPressed and buttonReleased
    to handle the push and release of the button.
    The name of the button will be passed back to the handler to identify
    which button was pressed/released
    """
    
    def __init__(self, pin, name, *, handler=None, lowActive=True):
        """
        Constructor - set up attributes hardware pin, and the IRQ
        """
        
        self._pinNo = pin
        self._name = name
        Log.i(f'Button constructor: create button {name} at pin {pin}')
        if lowActive:
            self._pin = Pin(pin, Pin.IN, Pin.PULL_UP)
        else:
            self._pin = Pin(pin, Pin.IN, Pin.PULL_DOWN)
        self._debounce_time = 0
        self._lowActive = lowActive
        self._lastStatus = None
        self._handler = handler
        self._pin.irq(trigger = Pin.IRQ_FALLING | Pin.IRQ_RISING, handler = self._callback)

    def isPressed(self):
        """ Check if the button is pressed or not - useful if polling """
        
        return (self._lowActive and self._pin.value() ==0) or (not self._lowActive and self._pin.value() == 1)
    
    def setHandler(self, handler):
        """ A class that has buttonPressed(name) and buttonReleased(name) methods """
        
        self._handler = handler
        
    def _callback(self, pin):
        """ The private interrupt handler - will call appropriate handlers """
        
        t = time.ticks_ms()
        v = self._pin.value()
        if ((self._lastStatus == None or self._lastStatus != v) and t-self._debounce_time) > 50:
            self._debounce_time=t
            self._lastStatus = v
            if self._handler is not None:
                if self.isPressed():
                    self._handler.buttonPressed(self._name)
                else:
                    self._handler.buttonReleased(self._name)
        #self._debounce_time=t

class Joystick(Button):
    """
    A joystick is technically more than a Button, but this is an example
    of using a subclass to inherit some functionality, and adding other
    functions as needed. 

    So we implement a Joystick as a subclass of a button, with the internal
    button inherited from the Button class, and the horizontal and vertical
    axes implemented as ADC pin implementations. 

    Interestingly, we may have looked into AnalogSensor as well, but there is
    no tripping of a Joystick so we don't need that.
    """
    
    # Some constants to store some basic conditions
    LOW = 0
    HIGH = 65535
    MID = 32760

    # Joystick status codes
    CENTER = 0
    UP = 1
    DOWN = 2
    LEFT = 3
    RIGHT = 4
    MOVING = 5
    
    # Status text
    statuscodes = ['Center', 'Up', 'Down', 'Left', 'Right', 'Moving']

    def __init__(self, vpin, hpin, swpin, name, *, handler=None, delta=1000):
        # Let the superclass handle all button functionality
        super().__init__(swpin, name, handler=handler, lowActive=True)
        Log.i(f'Joystick constructor: create joystick at v:{vpin}, h:{hpin}')

        # H and V axis pins must be standard ADC supporting
        if vpin <26 or vpin > 28 or hpin < 26 or hpin > 28:
            raise ValueError("Joystick Error: must connect v/h to ADC pins")

        self._v = ADC(vpin)
        self._h = ADC(hpin)
        self._delta = delta

    def getData(self):
        """
        A simple method to return the x and y values
        """

        return (self._h.read_u16(), self._v.read_u16())

    def getStatusCode(self):
        """
        Return the status code of the joystick
        0 - center, 1 left 2 right 3 up 4 down
        5 if it is not quite in any distinct position
        """

        (x,y) = self.getData()

        if x < self.LOW + self._delta:
            return self.RIGHT
        if x > self.HIGH - self._delta:
            return self.LEFT
        if y < self.LOW + self._delta:
            return self.DOWN
        if y > self.HIGH - self._delta:
            return self.UP
        if x > self.MID - self._delta and x < self.MID + self._delta and y > self.MID - self._delta and y < self.MID + self._delta:
            return self.CENTER
        return self.MOVING

    def getStatus(self):
        """
        Get the status of the joystick in text
        center, left, right, up, down, moving
        """
    
        return Joystick.statuscodes[self.getStatusCode()]


Button.py

"""
# Buzzer.py - Object-oriented implementation of active and passive buzzers
# Author: Arijit Sengupta
"""

import time
from machine import Pin, PWM
from Log import *

class Buzzer:
    """
    A simple buzzer class - use it to play and pause different sounds
    ranging from fequencies 10 through 10000
    default volume is half volume - set it between 0 and 10
    """
    
    def __init__(self, pin, name='Buzzer'):
        """
        Base class init - we don't do anything with the pin here
        """
        
        self._name = name
        
    def beep(self, tone=500, duration=150):
        """
        Beep the buzzer with the given tone for duration ms
        """
        
        Log.i(f"Beeping {self._name} at {tone}hz for {duration} ms")
        self.play(tone)
        time.sleep(duration / 1000)
        self.stop()
    
class ActiveBuzzer(Buzzer):
    """
    An active buzzer has an internal oscillator that plays a fixed tone when power is applied
    Cannot control the tone. Only turn on and off.
    """
    
    def __init__(self, pin, name='Buzzer'):
        super().__init__(pin, name)
        self._buz = Pin(pin, Pin.OUT)
   
    def play(self, tone=500):
        """ Play sound. Tone is ignored. """
        
        Log.i(f"Start playing {self._name}")
        self._buz.value(1)
        
    def stop(self):
        """ Stop the sound. """
        
        Log.i(f"Stop playing {self._name}")
        self._buz.value(0)
    
class PassiveBuzzer(Buzzer):
    """
    A passive buzzer does not have an internal oscillator. MC needs to send a PWM signal
    to play tones. The tone is controlled by the frequency of the PWM, and the volume level
    is controlled by the duty cycle. Setting duty cycle to 0 stops sound.
    """
    
    def __init__(self, pin, name='Buzzer'):
        Log.i("PassiveBuzzer: constructor")
        super().__init__(pin, name)
        self._buz = PWM(Pin(pin))
        self._volume = 5
        self._playing = False
        self.stop()

    def play(self, tone=500):
        """ play the supplied tone. """
        
        Log.i(f"{self._name}: playing tone {tone}")
        self._buz.freq(tone)
        self._buz.duty_u16(self._volume * 100)
        self._playing = True

    def stop(self):
        """ Stop playing sound """
        
        Log.i(f"{self._name}: stopping tone")
        self._buz.duty_u16(0)
        self._playing = False

    def setVolume(self, volume=5):
        """ Change the volume of the sound currently playing and future plays """
        
        Log.i(f"{self._name}: changing volume to {volume}")
        self._volume = volume
        if (self._playing):
            self._buz.duty_u16(self._volume * 100)

# Known tones from https://github.com/james1236/buzzer_music
tones = {
    'C0':16,
    'C#0':17,
    'D0':18,
    'D#0':19,
    'E0':21,
    'F0':22,
    'F#0':23,
    'G0':24,
    'G#0':26,
    'A0':28,
    'A#0':29,
    'B0':31,
    'C1':33,
    'C#1':35,
    'D1':37,
    'D#1':39,
    'E1':41,
    'F1':44,
    'F#1':46,
    'G1':49,
    'G#1':52,
    'A1':55,
    'A#1':58,
    'B1':62,
    'C2':65,
    'C#2':69,
    'D2':73,
    'D#2':78,
    'E2':82,
    'F2':87,
    'F#2':92,
    'G2':98,
    'G#2':104,
    'A2':110,
    'A#2':117,
    'B2':123,
    'C3':131,
    'C#3':139,
    'D3':147,
    'D#3':156,
    'E3':165,
    'F3':175,
    'F#3':185,
    'G3':196,
    'G#3':208,
    'A3':220,
    'A#3':233,
    'B3':247,
    'C4':262,
    'C#4':277,
    'D4':294,
    'D#4':311,
    'E4':330,
    'F4':349,
    'F#4':370,
    'G4':392,
    'G#4':415,
    'A4':440,
    'A#4':466,
    'B4':494,
    'C5':523,
    'C#5':554,
    'D5':587,
    'D#5':622,
    'E5':659,
    'F5':698,
    'F#5':740,
    'G5':784,
    'G#5':831,
    'A5':880,
    'A#5':932,
    'B5':988,
    'C6':1047,
    'C#6':1109,
    'D6':1175,
    'D#6':1245,
    'E6':1319,
    'F6':1397,
    'F#6':1480,
    'G6':1568,
    'G#6':1661,
    'A6':1760,
    'A#6':1865,
    'B6':1976,
    'C7':2093,
    'C#7':2217,
    'D7':2349,
    'D#7':2489,
    'E7':2637,
    'F7':2794,
    'F#7':2960,
    'G7':3136,
    'G#7':3322,
    'A7':3520,
    'A#7':3729,
    'B7':3951,
    'C8':4186,
    'C#8':4435,
    'D8':4699,
    'D#8':4978,
    'E8':5274,
    'F8':5588,
    'F#8':5920,
    'G8':6272,
    'G#8':6645,
    'A8':7040,
    'A#8':7459,
    'B8':7902,
    'C9':8372,
    'C#9':8870,
    'D9':9397,
    'D#9':9956,
    'E9':10548,
    'F9':11175,
    'F#9':11840,
    'G9':12544,
    'G#9':13290,
    'A9':14080,
    'A#9':14917,
    'B9':15804
}

# Some basic do re mi tones
DO = tones['C4']
RE = tones['D4']
MI = tones['E4']
FA = tones['F4']
SO = tones['G4']
LA = tones['A4']
TI = tones['B4']
DO2 = tones['C5']


Buzzer.py

"""
# Displays.py
# A collection of various text-based displays
# Note - as of 7/31/24 only the LCDDisplay is implemented in this module
# Use OtherDisplays.py, GraphicDisplays.py and GraphicLCD.py for the rest
# Supports LCD 1602 displays - both using an i2c backpack as well as GPIO
# Only supports number and basic text displays 
# Author: Arijit Sengupta
"""

from machine import Pin, I2C, SPI
import time
from Log import *
from gpio_lcd import *
from pico_i2c_lcd import I2cLcd

class Display:
    """
    The Display Base class - might not actually be needed
    But here to ensure we do not have a duckTyping problem
    """

    def reset(self):
        Log.e(f"reset NOT IMPLEMENTED in {type(self).__name__}")
        
    def clear(self):
        self.reset()

    def showNumber(self, number):
        Log.e(f"showNumber NOT IMPLEMENTED! in {type(self).__name__}")

    def showText(self, text):
        Log.e(f"showText NOT IMPLEMENTED! in {type(self).__name__}")

    def scroll(self, text, speed=250):
        Log.e(f"Scroll NOT IMPLEMENTED! in {type(self).__name__}")

class LCDDisplay(Display):
    """
    LCD Display class - currently supports displays with an I2C backpack
    as well as displays directly driven via the d4-d7 pins
    
    Parameters
    --------
    This is important since Python does not have method overloading, we have one init
    to do both parallel as well as i2c displays
    pass rs, e, d4, d5, d6, d7 pin numbers for parallel displays
    
    pass sda, scl, i2cid for i2c displays - default is to use parallel so must pass sda/scl/i2cid
    if using i2c
    
    To connect the display to I2C 0 on GPIO pins 0,1
    usage: LCDDisplay(sda=0, scl=1, i2cid=0)
    
    To connect the display to I2C ID 1 on GPIO pins 2,3
    usage: LCDDisplay(sda=2, scl=3, i2cid=1)
    
    To connect via parallel with rs on pin 5, e on pin 4
    and d4,d5,d6,d7 to pins 3,2,1 and 0:
    usage:  LCDDisplay()  # yeah those are the default so you don't need to send
    usage: LCDDisplay(rs=5, e=4, d4=3, d5=2, d6=1, d7=0) # preferred - you can see how its hooked up
    
    """
    
    def __init__(self, rs=5, e=4, d4=3, d5=2, d6=1, d7=0, *, sda=-1, scl=-1):
        """
        Combined constructor for the direct-driven displays
        explicitly pass in the sda and scl if you need to use I2C
        """
        
        if sda < 0:
            Log.i("LCDDisplay Constructor")
            self._lcd = GpioLcd(rs_pin=Pin(rs),
                enable_pin=Pin(e),
                d4_pin=Pin(d4),
                d5_pin=Pin(d5),
                d6_pin=Pin(d6),
                d7_pin=Pin(d7),
                num_lines=2, num_columns=16)
        else:
            Log.i("LCDDisplay (I2C) Constructor")
            """
            Lets determine the i2c id from the sda and scl pins
            """
            i2cid = -1 # lets set an invalid value to start with
            if (sda == 0 and scl == 1) or (sda == 4 and scl == 5) or (sda == 8 and scl == 9) or (sda == 12 and scl == 13) or (sda == 16 and scl == 17) or (sda == 20 and scl == 21):    
                i2cid = 0
            elif (sda == 2 and scl == 3) or (sda == 6 and scl == 7) or (sda == 10 and scl == 11) or (sda == 14 and scl == 15) or (sda == 18 and scl == 19) or (sda == 26 and scl == 27):
                i2cid = 1
            else:
                raise ValueError('Invalid SDA/SCL pins')
            i2c = I2C(i2cid, sda=Pin(sda), scl=Pin(scl), freq=400000)
            try:
                I2C_ADDR = i2c.scan()[0]
                self._lcd = I2cLcd(i2c, I2C_ADDR, 2, 16)
            except:
                raise ValueError('Could not connect to display - check wiring.')
        self._working = False

    def reset(self):
        """ 
        clear the display screen
        """
        
        Log.i("LCDDisplay: reset")
        self._lcd.clear()
        self._working = False

    def showNumber(self, number, row=0, col=0):
        """
        show a single number
        """
        
        if self._working:
            Log.e("LCDDisplay - Display busy")
            return
        self._working = True
        Log.i(f"LCDDisplay - showing number {number} at {row},{col}")
        self._lcd.move_to(col, row)
        self._lcd.putstr(f"{number}")
        self._working = False

    def showNumbers(self, num1, num2, colon=True, row=0, col=0):
        """
        Show two numbers optionally separated by a colon
        by default, the colon is shown
        """
        
        if self._working:
            Log.e("LCDDisplay - Display busy")
            return
        self._working = True
        Log.i(f"LCDDisplay - showing numbers {num1}, {num2} at {row},{col}")
        self._lcd.move_to(col, row)
        colsym = ":" if colon else " "
        self._lcd.putstr(f"{num1}{colsym}{num2}")
        self._working = False

    def showText(self, text, row=0, col=0):
        """
        Show a string - only first 4 characters will be shown
        for anything bigger than 4 characters.
        """
        
        if self._working:
            Log.e("LCDDisplay - Display busy")
            return
        self._working = True
        Log.i(f"LCDDisplay - showing text {text} at {row},{col}")
        self._lcd.move_to(col, row)
        self._lcd.putstr(text)
        self._working = False

    def addShape(self, position, shapearray):
        """
        Add a custom character at a position.
        position must be between 0 and 7
        shapearray needs to be a bytearray that can
        be created by going to
        https://maxpromer.github.io/LCD-Character-Creator/
        and then copying the bytes into a bytearray as a list of hex values
        as in the example below:

        d.addShape(1, [0x00,0x0A,0x0A,0x00,0x11,0x0E,0x04,0x00]) # a smiley face
        d.showText(chr(1), 0,5) # show the smiley face at position 5 of row 0
        """
        
        if position < 0 or position > 7:
            raise ValueError('Position must be between 0 and 7.')
        if len(shapearray) != 8:
            raise ValueError('Make sure array is exactly 8 bytes')
        self._lcd.custom_char(position, shapearray)

    def scroll(self, text, row=0, speed=100, skip=2):
        """
        A very simple scroll implementation
        Scrolls some text right to left in a row

        speed is essentially the delay between refresh - lower the better
        skip is the number of chars to skip for the next refresh
        higher number will be faster but may be jerky. lower will be smooth
        but slower.

        I2C devices may not have best scrolling performance. Works
        better with GPIO-driven displays
        """

        if self._working:
            Log.e("LCDDisplay - Display busy")
            return
        self._working = True
        Log.i(f"LCDDisplay - scrolling text {text} in row {row}")
        for p in range(0,len(text)+skip, skip):
            curst = (text+' '*(16+skip))[p:p+16]
            for c in range(16,0,-1):
                self._lcd.move_to(c-1, row)
                self._lcd.putchar(curst[c-1])
            time.sleep(speed/1000)
        self._working = False


Displays.py

"""
# LightStrip.py
# Re-implementing the old NeoPixel class into a LightStrip class
# Using the built-in neopixel class in MicroPython now
"""

import time, neopixel, machine
from Lights import *
from Log import *

class LightStrip(Light):
    """
    Although technically a composite light, a neopixel is a PIO-driven set of lights
    using a single output pin. So you do not send it composite lights, but just the pin
    it is connected to. It is a composite light because it has multiple lights, but
    they cannot technically be controlled individually.
    """

    FILLS = 0
    CHASES = 1
    RAINBOW = 2

    def __init__(self, pin=2, name='Neopixel', numleds=16, brightness=0.5):
        """
        Constructor for neopixel will create its own internal statemachine
        Note that if any other state machine is running, this will break the existing
        statemachine. This refers to the Pico PIO statemachine, not any software state
        machines.
        """
        
        self._name = name
        self._pin = pin
        self._numleds = numleds
        self._brightness = brightness
        self._running = False
        
        Log.i(f'Creating a neopixel {name} on pin {pin} with {numleds} LEDs')
        self._np = neopixel.NeoPixel(machine.Pin(pin), numleds)

    def on(self):
        """ Turn all LEDs ON - all white """

        self._fill(WHITE)
        self._np.write()
        Log.i(f'{self._name} ON')
    
    def off(self):
        """ Turn all LEDs OFF - all black """
        
        self._running = False
        time.sleep(0.1)
        self._clear()
        self._np.write()
        Log.i(f'{self._name} OFF')

    def flip(self):
        """ Flip the clors on all the LEDs """
        
        for x in range(0, self._numleds):
            self._np[x] = (255-self._np[x][0], 255-self._np[x][1], 255-self._np[x][2])
        self.show()
        Log.i(f'{self._name} flipped')

    def setColor(self, color, numPixels= -1):
        """ Turn all LEDs up to a set number of pixels to a specific color """
        
        if numPixels < 0 or numPixels > self._numleds:
            numPixels = self._numleds
        for i in range(numPixels):
            self._set_pixel(i, color)
        for i in range(numPixels,self._numleds):
            self._set_pixel(i, BLACK)
        self._np.write()
        Log.i(f'{self._name} set color to {color}')

    def setPixel(self, pixelno, color, show=True):
        """
        Turn a single pixel a specific color
        By default the new color is immediately shown.
        To make multiple changes, you can speed up by setting
        show to False, then calling the show method
        """
        
        self._set_pixel(pixelno, color)
        if show:
            self._np.write()
        Log.i(f'{self._name} set pixel {pixelno} to color {color}')

    def show(self):
        """
        Shows what is in the color buffer. Useful if previous
        setPixel was called without show On
        """
        
        self._np.write()
        
    def setBrightness(self, brightness=0.5):
        """ Change the brightness of the pixel 0-1 range """
        
        self._brightness = brightness
        Log.i(f'{self._name} set brightness to {brightness}')
        
    def run(self, runtype=0):
        """ Run a single cycle of FILLS, CHASES or RAINBOW """
        
        self._running = True
        if runtype == LightStrip.FILLS:
            Log.i(f'{self._name} running fills')
            for color in COLORS:
                if not self._running:
                    break       
                self.setColor(color)
                time.sleep(0.2)
        elif runtype == LightStrip.CHASES:
            Log.i(f'{self._name} running chases')
            for color in COLORS:
                if not self._running:
                    break       
                self.color_chase(color, 0.01)
        else:
            Log.i(f'{self._name} running rainbow')
            self.rainbow_cycle(0)
        self._running = False


    ################# Internal functions should not be used outside here #################
    def _set_pixel(self, p, color):
        modifiedcolor = tuple(int(col*self._brightness) for col in color)
        self._np[p] = modifiedcolor

    def _clear(self):
        self._np.fill(BLACK)
        pass

    def _fill(self, color):
        self._np.fill(color)
        pass


    def color_chase(self, color, wait):
        for i in range(self._numleds):
            if not self._running:
                break
            self._set_pixel(i, color)
            time.sleep(wait)
            self._np.write()
        time.sleep(0.2)
    
    def wheel(self, pos):
        # Input a value 0 to 255 to get a color value.
        # The colours are a transition r - g - b - back to r.
        if pos < 0 or pos > 255:
            return (0, 0, 0)
        if pos < 85:
            return (255 - pos * 3, pos * 3, 0)
        if pos < 170:
            pos -= 85
            return (0, 255 - pos * 3, pos * 3)
        pos -= 170
        return (pos * 3, 0, 255 - pos * 3)
    
    
    def rainbow_cycle(self, wait):
        for j in range(255):
            if not self._running:
                break
            for i in range(self._numleds):
                rc_index = (i * 256 // self._numleds) + j
                self._set_pixel(i, self.wheel(rc_index & 255))
            self._np.write()
            time.sleep(wait)


# Some color definitions
BLACK = (0, 0, 0)
RED = (255, 0, 0)
ORANGE = (255, 140, 0)
YELLOW = (255, 200, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)
PURPLE = (180, 0, 255)
CYAN = (0, 255, 255)
INDIGO = (75, 0, 130)
WHITE = (255, 255, 255)
COLORS = (BLACK, RED, YELLOW, GREEN, CYAN, BLUE, PURPLE, WHITE, ORANGE)



LightStrip.py

"""Source: Instructables, Tom's Hardware and GitHub """
"""Not Authored by Dr. Sengupta """
"""Implements a HD44780 character LCD connected via ESP32/RPi GPIO pins."""

from lcd_api import LcdApi
from machine import Pin
from utime import sleep_ms, sleep_us


class GpioLcd(LcdApi):
    """Implements a HD44780 character LCD connected via ESP32 GPIO pins."""

    def __init__(self, rs_pin, enable_pin, d0_pin=None, d1_pin=None,
                 d2_pin=None, d3_pin=None, d4_pin=None, d5_pin=None,
                 d6_pin=None, d7_pin=None, rw_pin=None, backlight_pin=None,
                 num_lines=2, num_columns=16):
        """Constructs the GpioLcd object. All of the arguments must be machine.Pin
        objects which describe which pin the given line from the LCD is
        connected to.
        When used in 4-bit mode, only D4, D5, D6, and D7 are physically
        connected to the LCD panel. This function allows you call it like
        GpioLcd(rs, enable, D4, D5, D6, D7) and it will interpret that as
        if you had actually called:
        GpioLcd(rs, enable, d4=D4, d5=D5, d6=D6, d7=D7)
        The enable 8-bit mode, you need pass d0 through d7.
        The rw pin isn't used by this library, but if you specify it, then
        it will be set low.
        """
        self.rs_pin = rs_pin
        self.enable_pin = enable_pin
        self.rw_pin = rw_pin
        self.backlight_pin = backlight_pin
        self._4bit = True
        if d4_pin and d5_pin and d6_pin and d7_pin:
            self.d0_pin = d0_pin
            self.d1_pin = d1_pin
            self.d2_pin = d2_pin
            self.d3_pin = d3_pin
            self.d4_pin = d4_pin
            self.d5_pin = d5_pin
            self.d6_pin = d6_pin
            self.d7_pin = d7_pin
            if self.d0_pin and self.d1_pin and self.d2_pin and self.d3_pin:
                self._4bit = False
        else:
            # This is really 4-bit mode, and the 4 data pins were just
            # passed as the first 4 arguments, so we switch things around.
            self.d0_pin = None
            self.d1_pin = None
            self.d2_pin = None
            self.d3_pin = None
            self.d4_pin = d0_pin
            self.d5_pin = d1_pin
            self.d6_pin = d2_pin
            self.d7_pin = d3_pin
        self.rs_pin.init(Pin.OUT)
        self.rs_pin.value(0)
        if self.rw_pin:
            self.rw_pin.init(Pin.OUT)
            self.rw_pin.value(0)
        self.enable_pin.init(Pin.OUT)
        self.enable_pin.value(0)
        self.d4_pin.init(Pin.OUT)
        self.d5_pin.init(Pin.OUT)
        self.d6_pin.init(Pin.OUT)
        self.d7_pin.init(Pin.OUT)
        self.d4_pin.value(0)
        self.d5_pin.value(0)
        self.d6_pin.value(0)
        self.d7_pin.value(0)
        if not self._4bit:
            self.d0_pin.init(Pin.OUT)
            self.d1_pin.init(Pin.OUT)
            self.d2_pin.init(Pin.OUT)
            self.d3_pin.init(Pin.OUT)
            self.d0_pin.value(0)
            self.d1_pin.value(0)
            self.d2_pin.value(0)
            self.d3_pin.value(0)
        if self.backlight_pin is not None:
            self.backlight_pin.init(Pin.OUT)
            self.backlight_pin.value(0)

        # See about splitting this into begin

        sleep_ms(20)   # Allow LCD time to powerup
        # Send reset 3 times
        self.hal_write_init_nibble(self.LCD_FUNCTION_RESET)
        sleep_ms(5)    # need to delay at least 4.1 msec
        self.hal_write_init_nibble(self.LCD_FUNCTION_RESET)
        sleep_ms(1)
        self.hal_write_init_nibble(self.LCD_FUNCTION_RESET)
        sleep_ms(1)
        cmd = self.LCD_FUNCTION
        if not self._4bit:
            cmd |= self.LCD_FUNCTION_8BIT
        self.hal_write_init_nibble(cmd)
        sleep_ms(1)
        LcdApi.__init__(self, num_lines, num_columns)
        if num_lines > 1:
            cmd |= self.LCD_FUNCTION_2LINES
        self.hal_write_command(cmd)

    def hal_pulse_enable(self):
        """Pulse the enable line high, and then low again."""
        self.enable_pin.value(0)
        sleep_us(1)
        self.enable_pin.value(1)
        sleep_us(1)       # Enable pulse needs to be > 450 nsec
        self.enable_pin.value(0)
        sleep_us(100)     # Commands need > 37us to settle

    def hal_write_init_nibble(self, nibble):
        """Writes an initialization nibble to the LCD.
        This particular function is only used during initialization.
        """
        self.hal_write_4bits(nibble >> 4)

    def hal_backlight_on(self):
        """Allows the hal layer to turn the backlight on."""
        if self.backlight_pin:
            self.backlight_pin.value(1)

    def hal_backlight_off(self):
        """Allows the hal layer to turn the backlight off."""
        if self.backlight_pin:
            self.backlight_pin.value(0)

    def hal_write_command(self, cmd):
        """Writes a command to the LCD.
        Data is latched on the falling edge of E.
        """
        self.rs_pin.value(0)
        self.hal_write_8bits(cmd)
        if cmd <= 3:
            # The home and clear commands require a worst
            # case delay of 4.1 msec
            sleep_ms(5)

    def hal_write_data(self, data):
        """Write data to the LCD."""
        self.rs_pin.value(1)
        self.hal_write_8bits(data)

    def hal_write_8bits(self, value):
        """Writes 8 bits of data to the LCD."""
        if self.rw_pin:
            self.rw_pin.value(0)
        if self._4bit:
            self.hal_write_4bits(value >> 4)
            self.hal_write_4bits(value)
        else:
            self.d3_pin.value(value & 0x08)
            self.d2_pin.value(value & 0x04)
            self.d1_pin.value(value & 0x02)
            self.d0_pin.value(value & 0x01)
            self.hal_write_4bits(value >> 4)

    def hal_write_4bits(self, nibble):
        """Writes 4 bits of data to the LCD."""
        self.d7_pin.value(nibble & 0x08)
        self.d6_pin.value(nibble & 0x04)
        self.d5_pin.value(nibble & 0x02)
        self.d4_pin.value(nibble & 0x01)
        self.hal_pulse_enable()

gpio_lcd.py

"""Source: Instructables, Tom's Hardware and GitHub """
"""Not Authored by Dr. Sengupta """
"""Provides an API for talking to HD44780 compatible character LCDs."""

import time

class LcdApi:
    """Implements the API for talking with HD44780 compatible character LCDs.
    This class only knows what commands to send to the LCD, and not how to get
    them to the LCD.
    It is expected that a derived class will implement the hal_xxx functions.
    """

    # The following constant names were lifted from the avrlib lcd.h
    # header file, however, I changed the definitions from bit numbers
    # to bit masks.
    #
    # HD44780 LCD controller command set

    LCD_CLR = 0x01              # DB0: clear display
    LCD_HOME = 0x02             # DB1: return to home position

    LCD_ENTRY_MODE = 0x04       # DB2: set entry mode
    LCD_ENTRY_INC = 0x02        # --DB1: increment
    LCD_ENTRY_SHIFT = 0x01      # --DB0: shift

    LCD_ON_CTRL = 0x08          # DB3: turn lcd/cursor on
    LCD_ON_DISPLAY = 0x04       # --DB2: turn display on
    LCD_ON_CURSOR = 0x02        # --DB1: turn cursor on
    LCD_ON_BLINK = 0x01         # --DB0: blinking cursor

    LCD_MOVE = 0x10             # DB4: move cursor/display
    LCD_MOVE_DISP = 0x08        # --DB3: move display (0-> move cursor)
    LCD_MOVE_RIGHT = 0x04       # --DB2: move right (0-> left)

    LCD_FUNCTION = 0x20         # DB5: function set
    LCD_FUNCTION_8BIT = 0x10    # --DB4: set 8BIT mode (0->4BIT mode)
    LCD_FUNCTION_2LINES = 0x08  # --DB3: two lines (0->one line)
    LCD_FUNCTION_10DOTS = 0x04  # --DB2: 5x10 font (0->5x7 font)
    LCD_FUNCTION_RESET = 0x30   # See "Initializing by Instruction" section

    LCD_CGRAM = 0x40            # DB6: set CG RAM address
    LCD_DDRAM = 0x80            # DB7: set DD RAM address

    LCD_RS_CMD = 0
    LCD_RS_DATA = 1

    LCD_RW_WRITE = 0
    LCD_RW_READ = 1

    def __init__(self, num_lines, num_columns):
        self.num_lines = num_lines
        if self.num_lines > 4:
            self.num_lines = 4
        self.num_columns = num_columns
        if self.num_columns > 40:
            self.num_columns = 40
        self.cursor_x = 0
        self.cursor_y = 0
        self.implied_newline = False
        self.backlight = True
        self.display_off()
        self.backlight_on()
        self.clear()
        self.hal_write_command(self.LCD_ENTRY_MODE | self.LCD_ENTRY_INC)
        self.hide_cursor()
        self.display_on()

    def clear(self):
        """Clears the LCD display and moves the cursor to the top left
        corner.
        """
        self.hal_write_command(self.LCD_CLR)
        self.hal_write_command(self.LCD_HOME)
        self.cursor_x = 0
        self.cursor_y = 0

    def show_cursor(self):
        """Causes the cursor to be made visible."""
        self.hal_write_command(self.LCD_ON_CTRL | self.LCD_ON_DISPLAY |
                               self.LCD_ON_CURSOR)

    def hide_cursor(self):
        """Causes the cursor to be hidden."""
        self.hal_write_command(self.LCD_ON_CTRL | self.LCD_ON_DISPLAY)

    def blink_cursor_on(self):
        """Turns on the cursor, and makes it blink."""
        self.hal_write_command(self.LCD_ON_CTRL | self.LCD_ON_DISPLAY |
                               self.LCD_ON_CURSOR | self.LCD_ON_BLINK)

    def blink_cursor_off(self):
        """Turns on the cursor, and makes it no blink (i.e. be solid)."""
        self.hal_write_command(self.LCD_ON_CTRL | self.LCD_ON_DISPLAY |
                               self.LCD_ON_CURSOR)

    def display_on(self):
        """Turns on (i.e. unblanks) the LCD."""
        self.hal_write_command(self.LCD_ON_CTRL | self.LCD_ON_DISPLAY)

    def display_off(self):
        """Turns off (i.e. blanks) the LCD."""
        self.hal_write_command(self.LCD_ON_CTRL)

    def backlight_on(self):
        """Turns the backlight on.
        This isn't really an LCD command, but some modules have backlight
        controls, so this allows the hal to pass through the command.
        """
        self.backlight = True
        self.hal_backlight_on()

    def backlight_off(self):
        """Turns the backlight off.
        This isn't really an LCD command, but some modules have backlight
        controls, so this allows the hal to pass through the command.
        """
        self.backlight = False
        self.hal_backlight_off()

    def move_to(self, cursor_x, cursor_y):
        """Moves the cursor position to the indicated position. The cursor
        position is zero based (i.e. cursor_x == 0 indicates first column).
        """
        self.cursor_x = cursor_x
        self.cursor_y = cursor_y
        addr = cursor_x & 0x3f
        if cursor_y & 1:
            addr += 0x40    # Lines 1 & 3 add 0x40
        if cursor_y & 2:    # Lines 2 & 3 add number of columns
            addr += self.num_columns
        self.hal_write_command(self.LCD_DDRAM | addr)

    def putchar(self, char):
        """Writes the indicated character to the LCD at the current cursor
        position, and advances the cursor by one position.
        """
        if char == '\n':
            if self.implied_newline:
                # self.implied_newline means we advanced due to a wraparound,
                # so if we get a newline right after that we ignore it.
                pass
            else:
                self.cursor_x = self.num_columns
        else:
            self.hal_write_data(ord(char))
            self.cursor_x += 1
        if self.cursor_x >= self.num_columns:
            self.cursor_x = 0
            self.cursor_y += 1
            self.implied_newline = (char != '\n')
        if self.cursor_y >= self.num_lines:
            self.cursor_y = 0
        self.move_to(self.cursor_x, self.cursor_y)

    def putstr(self, string):
        """Write the indicated string to the LCD at the current cursor
        position and advances the cursor position appropriately.
        """
        for char in string:
            self.putchar(char)

    def custom_char(self, location, charmap):
        """Write a character to one of the 8 CGRAM locations, available
        as chr(0) through chr(7).
        """
        location &= 0x7
        self.hal_write_command(self.LCD_CGRAM | (location << 3))
        self.hal_sleep_us(40)
        for i in range(8):
            self.hal_write_data(charmap[i])
            self.hal_sleep_us(40)
        self.move_to(self.cursor_x, self.cursor_y)

    def hal_backlight_on(self):
        """Allows the hal layer to turn the backlight on.
        If desired, a derived HAL class will implement this function.
        """
        pass

    def hal_backlight_off(self):
        """Allows the hal layer to turn the backlight off.
        If desired, a derived HAL class will implement this function.
        """
        pass

    def hal_write_command(self, cmd):
        """Write a command to the LCD.
        It is expected that a derived HAL class will implement this
        function.
        """
        raise NotImplementedError

    def hal_write_data(self, data):
        """Write data to the LCD.
        It is expected that a derived HAL class will implement this
        function.
        """
        raise NotImplementedError

    def hal_sleep_us(self, usecs):
        """Sleep for some time (given in microseconds)."""
        time.sleep_us(usecs)

lcd_api.py

"""
Log.py - a simplistic Logging process. Built to kind of mimic the
Android Logging process, but at the same time having a global level
set to see the types of logs being displayed.

Basic usage:

Log.level = DEBUG  # set global log level

# Options are: ALL/INFO (everything) DEBUG (debug and higher), ERRO (only errors)
Log.i(f'help')     # Info message: f-strings recommended for showing variables
Log.d(f'value: {v}') # Debug message
Log.e(f'Exception: {x}') # Error message
Log.name('Myproject') # Set a global project name
"""

""" Debug levels """
ALL = 4  # All messages are displayed
INFO = 3  # Basically the same as ALL - for future-proofing
DEBUG = 2  # Info is hidden - debug and higher shown
ERROR = 1  # Only error messages shown
NONE = 0  # No messages are shown from log classes


class Log:

    name = ''
    level = ALL

    @classmethod
    def i(cls, message):
        if (cls.level >= INFO):
            Log.pr(message)

    @classmethod
    def d(cls, message):
        if (cls.level >= DEBUG):
            Log.pr(message)

    @classmethod
    def e(cls, message):
        if (cls.level >= ERROR):
            Log.pr(message)

    @classmethod
    def pr(cls, message):
        if cls.name:
            m = cls.name + ": " + message
        else:
            m = message
        print(m)


if __name__ == '__main__':
    print("Hello")
    Log.level = ALL
    Log.name = 'Test'
    Log.i(f'This should print (level: {Log.level})')
    
    Log.level = ERROR
    Log.i(f'This should NOT print (level: {Log.level})')
    Log.e(f'This should print (level: {Log.level})')
    



Log.py

"""Source: Instructables, Tom's Hardware and GitHub """
"""Not Authored by Dr. Sengupta """

import utime
import gc

from lcd_api import LcdApi
from machine import I2C

# PCF8574 pin definitions
MASK_RS = 0x01       # P0
MASK_RW = 0x02       # P1
MASK_E  = 0x04       # P2

SHIFT_BACKLIGHT = 3  # P3
SHIFT_DATA      = 4  # P4-P7

class I2cLcd(LcdApi):
    
    #Implements a HD44780 character LCD connected via PCF8574 on I2C

    def __init__(self, i2c, i2c_addr, num_lines, num_columns):
        self.i2c = i2c
        self.i2c_addr = i2c_addr
        self.i2c.writeto(self.i2c_addr, bytes([0]))
        utime.sleep_ms(20)   # Allow LCD time to powerup
        # Send reset 3 times
        self.hal_write_init_nibble(self.LCD_FUNCTION_RESET)
        utime.sleep_ms(5)    # Need to delay at least 4.1 msec
        self.hal_write_init_nibble(self.LCD_FUNCTION_RESET)
        utime.sleep_ms(1)
        self.hal_write_init_nibble(self.LCD_FUNCTION_RESET)
        utime.sleep_ms(1)
        # Put LCD into 4-bit mode
        self.hal_write_init_nibble(self.LCD_FUNCTION)
        utime.sleep_ms(1)
        LcdApi.__init__(self, num_lines, num_columns)
        cmd = self.LCD_FUNCTION
        if num_lines > 1:
            cmd |= self.LCD_FUNCTION_2LINES
        self.hal_write_command(cmd)
        gc.collect()

    def hal_write_init_nibble(self, nibble):
        # Writes an initialization nibble to the LCD.
        # This particular function is only used during initialization.
        byte = ((nibble >> 4) & 0x0f) << SHIFT_DATA
        self.i2c.writeto(self.i2c_addr, bytes([byte | MASK_E]))
        self.i2c.writeto(self.i2c_addr, bytes([byte]))
        gc.collect()
        
    def hal_backlight_on(self):
        # Allows the hal layer to turn the backlight on
        self.i2c.writeto(self.i2c_addr, bytes([1 << SHIFT_BACKLIGHT]))
        gc.collect()
        
    def hal_backlight_off(self):
        #Allows the hal layer to turn the backlight off
        self.i2c.writeto(self.i2c_addr, bytes([0]))
        gc.collect()
        
    def hal_write_command(self, cmd):
        # Write a command to the LCD. Data is latched on the falling edge of E.
        byte = ((self.backlight << SHIFT_BACKLIGHT) |
                (((cmd >> 4) & 0x0f) << SHIFT_DATA))
        self.i2c.writeto(self.i2c_addr, bytes([byte | MASK_E]))
        self.i2c.writeto(self.i2c_addr, bytes([byte]))
        byte = ((self.backlight << SHIFT_BACKLIGHT) |
                ((cmd & 0x0f) << SHIFT_DATA))
        self.i2c.writeto(self.i2c_addr, bytes([byte | MASK_E]))
        self.i2c.writeto(self.i2c_addr, bytes([byte]))
        if cmd <= 3:
            # The home and clear commands require a worst case delay of 4.1 msec
            utime.sleep_ms(5)
        gc.collect()

    def hal_write_data(self, data):
        # Write data to the LCD. Data is latched on the falling edge of E.
        byte = (MASK_RS |
                (self.backlight << SHIFT_BACKLIGHT) |
                (((data >> 4) & 0x0f) << SHIFT_DATA))
        self.i2c.writeto(self.i2c_addr, bytes([byte | MASK_E]))
        self.i2c.writeto(self.i2c_addr, bytes([byte]))
        byte = (MASK_RS |
                (self.backlight << SHIFT_BACKLIGHT) |
                ((data & 0x0f) << SHIFT_DATA))      
        self.i2c.writeto(self.i2c_addr, bytes([byte | MASK_E]))
        self.i2c.writeto(self.i2c_addr, bytes([byte]))
        gc.collect()

pico_i2c_lcd.py

"""
# Lights.py
# implementation of different types of lights
# both digitally controlled (on/off)
# or PWM-controlled (dimming) to set brightness
# Author: Arijit Sengupta
"""

import utime
from machine import Pin, PWM
from Log import *
import _thread
MAX = 65535

baton = _thread.allocate_lock()

class Light:
    """
    The Light base class - just an LED controlled by a digital IO
    Pin. Save the pin in an instance variable
    """
    
    def __init__(self, pin, name="Unnamed"):
        """
        Light constructor - save the pin and set it to OUTPUT mode
        pin is the NUMBER of the pin that the LED is connected to. So
        if connecting to GP21, pass the value 21 to pin        
        name is an optional name of the light
        """
            
        Log.i(f"Light: constructor")
        self._name = name
        self._pin = pin
        self._blinking = False
        self._led = Pin(self._pin, Pin.OUT)  # We need this to use the IO functions

    def on(self):
        """ on: Turn the light on """
        
        Log.i(f"Light: turning on {self._name} light at pin {self._pin}")
        self._led.value(1)

    def off(self):
        """ off: turn the light off """
        
        Log.i(f"Light: turning off {self._name} light at pin {self._pin}")
        self._led.value(0)

    def flip(self):
        """ flip: turn off if it was on, on if it was off """
        
        Log.i(f"Light: Toggling {self._name} light at pin {self._pin}")
        self._led.toggle()

    def blink(self, delay=0.5, times=1):
        """ blink: turn on for delay sec, off for delay sec [times] times"""

        Log.i(f"Light: Blink {self._name} {times} times for {delay} sec")
        for x in range(0,times):
            self.on()
            utime.sleep(delay)
            self.off()
            utime.sleep(delay)


class DimLight(Light):
    """
    The Dimmable Light subclass - will have the standard on off methods
    and in addition will have the ability to set brightness
    """

    def __init__(self, pin, name="Unnamed"):
        """ Dimmable light constructor """

        Log.i("Dimmable light constructor")
        super().__init__(pin, name)
        self._pwm = PWM(self._led)  # Create an instance of PWM object (pulse-width modulation)
        self._pwm.freq(100000)   # set frequency to 100 khz
        self._onState = False
        self._running = False

    def on(self):
        """ Turn on - full brightness max is 255 """
        
        self._running = False
        self._onState = True
        Log.i(f"Dimlight: turn Light {self._name} on (full brightness)")
        self.setBrightness(MAX)

    def off(self):
        """  Turn off - set brightness to 0 """
        
        self._running = False
        self._onState = False
        Log.i(f"Dimlight - turn Light {self._name} off (brightness 0)")
        self.setBrightness(0)

    def flip(self):
        """ flip: turn off if it was on, on if it was off """
        
        Log.i(f"Light: Toggling {self._name} light at pin {self._pin}")
        if self._onState:
            self.off()
        else:
            self.on()       
        
    def setBrightness(self, brightness):
        """ Set brightness to a specific level 0-255 """

        Log.i(f"Dimlight: setting Light {self._name} brightness to {brightness}")
        if (brightness == MAX):
            self._pwm.duty_u16(MAX)
        else:
            self._pwm.duty_u16(brightness * brightness)
        
        if brightness < 50:
            self._onState = False
        else:
            self._onState = True

    def upDown(self):
        """
        # Do a quick demo of going up and down full brightness levels
        # Here it is better to use ChangeDutyCycle
        """
        
        Log.i(f"Dimlight: do an up-down demo on Light {self._name}")
        self._running = True
        dc = 0
        for i in range (0, 25):
            if not self._running:
                break
            dc += 10
            self.setBrightness(dc)
            utime.sleep_ms(100)

        for i in range (0, 25):
            if not self._running:
                break
            dc -= 10
            self.setBrightness(dc)
            utime.sleep_ms(100)
        self._running = False