diagram.json

import network
import time
from machine import Pin, I2C
from umqtt.simple import MQTTClient

import ssd1306

MQTT_CLIENT_ID = "micropython-tic-tac-toe"
MQTT_BROKER = "broker.mqttdashboard.com"
MQTT_TIC_TAC_TOE_TOPIC = "elsys/tic-tac-toe/board"
MQTT_TIC_TAC_TOE_PLAYER_TOPIC = "elsys/tic-tac-toe/player"

class Board:
    def __init__(self, display):
        self.display = display
        self.board = [[0, 0, 0], [0, 0, 0], [0, 0, 0]]
        self.current_player = 2

    def display_board(self):
        self.display.fill(0)

        for row in range(3):
            for col in range(3):
                x = col * 42
                y = row * 21
                value = self.board[row][col]
                if value == 1:
                    self.display.text("X", x + 10, y + 5)
                elif value == 2:
                    self.display.text("O", x + 10, y + 5)
                else:
                    self.display.text("-", x + 10, y + 5)

        self.display.show()
                
    def move_valid(self, row, col):
        return 0 <= row <= 2 and 0 <= col <= 2 and self.board[row][col] == 0

    def make_move(self, row, col, player_name):
        player_name = 1 if player_name == 'x' else 2

        if player_name == self.current_player:
            validation = self.move_valid(row, col)

            if validation:
                self.board[row][col] = self.current_player
                self.current_player = 2 if self.current_player == 1 else 1
                self.display_board()

                winner = self.check_for_winner()
                if winner != 0:
                    return winner
                elif self.check_board_full():
                    return 3
                else:
                    return 0
            
            return 4

        return 5

    def check_for_winner(self):
        for i in range(3):
            if self.board[i][0] == self.board[i][1] == self.board[i][2] != 0:
                return self.board[i][0]
            if self.board[0][i] == self.board[1][i] == self.board[2][i] != 0:
                return self.board[0][i]
        if self.board[0][0] == self.board[1][1] == self.board[2][2] != 0:
            return self.board[0][0]
        if self.board[0][2] == self.board[1][1] == self.board[2][0] != 0:
            return self.board[0][2]
        return 0

    def check_board_full(self):
        return all(self.board[row][col] != 0 
                  for row in range(3) for col in range(3))

    def reset_board(self):
        self.board = [[0, 0, 0], [0, 0, 0], [0, 0, 0]]
        self.display_board()


def connect_to_wifi():
    print("Connecting to Wi-Fi", end="")
    sta_if = network.WLAN(network.STA_IF)
    sta_if.active(True)
    sta_if.connect('Wokwi-GUEST', '')
    while not sta_if.isconnected():
        print(".", end="")
        time.sleep(0.1)
    print(" Connected!")

def connect_to_mqtt_broker():
    connect_to_wifi()
    print("Connecting to MQTT server... ", end="")
    client.connect()
    print("Connected!")
    client.subscribe(MQTT_TIC_TAC_TOE_TOPIC)
    print("Subscribed to {}".format(MQTT_TIC_TAC_TOE_TOPIC))

def on_message(topic, message):
    topic = topic.decode("utf-8")
    message = message.decode("utf-8")
    print("Received from MQTT topic: {} - message: {}".format(topic, message))

    player_name, row, col = message.split(",")
    row, col = int(row), int(col)

    move_code = board.make_move(row, col, player_name)

    print(player_name)

    msg = 0

    if move_code == 4:
        msg = "Invalid move."
        client.publish(MQTT_TIC_TAC_TOE_PLAYER_TOPIC + "/" + player_name,
                      msg)
        print("Published to: {} - message: {}"
        .format(MQTT_TIC_TAC_TOE_PLAYER_TOPIC + "/" + player_name, msg))

    elif move_code == 5:
        msg = "Not your turn."
        client.publish(MQTT_TIC_TAC_TOE_PLAYER_TOPIC + "/" + player_name,
                      msg)
        print("Published to: {} - message: {}"
        .format(MQTT_TIC_TAC_TOE_PLAYER_TOPIC + "/" + player_name, msg))

    elif move_code == 3:
        publish_to_both_clients("No more empty squares - it's a tie.")
        publish_to_both_clients("Cleaning up board.")

        time.sleep(30)
        board.reset_board();

        publish_to_both_clients("New game.")

    elif move_code == 1 or move_code == 2:
        winner = 'x' if move_code == 1 else 'o'
        publish_to_both_clients("Winner is player " + winner)
        publish_to_both_clients("Cleaning up board.")

        time.sleep(30)
        board.reset_board();

        publish_to_both_clients("New game.")

    else:
        msg = "Your turn."
        next_player = 'o' if board.current_player == 2 else 'x'
        client.publish(MQTT_TIC_TAC_TOE_PLAYER_TOPIC + "/" + next_player,
                      msg)
        print("Published to: {} - message: {}"
        .format(MQTT_TIC_TAC_TOE_PLAYER_TOPIC + "/" + next_player, msg))



def publish_to_both_clients(msg):
    client.publish(MQTT_TIC_TAC_TOE_PLAYER_TOPIC + "/x", msg)
    client.publish(MQTT_TIC_TAC_TOE_PLAYER_TOPIC + "/o", msg)

    print("Published to: {} - message: {}"
    .format(MQTT_TIC_TAC_TOE_PLAYER_TOPIC + "/x", msg))

    print("Published to: {} - message: {}"
    .format(MQTT_TIC_TAC_TOE_PLAYER_TOPIC + "/o", msg))



client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER)
client.set_callback(on_message)
connect_to_mqtt_broker()

i2c = I2C(0, scl=Pin(22), sda=Pin(21))

display_width = 128
display_height = 64
display = ssd1306.SSD1306_I2C(display_width, display_height, i2c)

board = Board(display)

try:
    while 1:
        client.wait_msg()
finally:
    client.disconnect()

main.py

#MicroPython SSD1306 OLED driver, I2C and SPI interfaces created by Adafruit

import time
import framebuf

# register definitions
SET_CONTRAST        = const(0x81)
SET_ENTIRE_ON       = const(0xa4)
SET_NORM_INV        = const(0xa6)
SET_DISP            = const(0xae)
SET_MEM_ADDR        = const(0x20)
SET_COL_ADDR        = const(0x21)
SET_PAGE_ADDR       = const(0x22)
SET_DISP_START_LINE = const(0x40)
SET_SEG_REMAP       = const(0xa0)
SET_MUX_RATIO       = const(0xa8)
SET_COM_OUT_DIR     = const(0xc0)
SET_DISP_OFFSET     = const(0xd3)
SET_COM_PIN_CFG     = const(0xda)
SET_DISP_CLK_DIV    = const(0xd5)
SET_PRECHARGE       = const(0xd9)
SET_VCOM_DESEL      = const(0xdb)
SET_CHARGE_PUMP     = const(0x8d)


class SSD1306:
    def __init__(self, width, height, external_vcc):
        self.width = width
        self.height = height
        self.external_vcc = external_vcc
        self.pages = self.height // 8
        # Note the subclass must initialize self.framebuf to a framebuffer.
        # This is necessary because the underlying data buffer is different
        # between I2C and SPI implementations (I2C needs an extra byte).
        self.poweron()
        self.init_display()

    def init_display(self):
        for cmd in (
            SET_DISP | 0x00, # off
            # address setting
            SET_MEM_ADDR, 0x00, # horizontal
            # resolution and layout
            SET_DISP_START_LINE | 0x00,
            SET_SEG_REMAP | 0x01, # column addr 127 mapped to SEG0
            SET_MUX_RATIO, self.height - 1,
            SET_COM_OUT_DIR | 0x08, # scan from COM[N] to COM0
            SET_DISP_OFFSET, 0x00,
            SET_COM_PIN_CFG, 0x02 if self.height == 32 else 0x12,
            # timing and driving scheme
            SET_DISP_CLK_DIV, 0x80,
            SET_PRECHARGE, 0x22 if self.external_vcc else 0xf1,
            SET_VCOM_DESEL, 0x30, # 0.83*Vcc
            # display
            SET_CONTRAST, 0xff, # maximum
            SET_ENTIRE_ON, # output follows RAM contents
            SET_NORM_INV, # not inverted
            # charge pump
            SET_CHARGE_PUMP, 0x10 if self.external_vcc else 0x14,
            SET_DISP | 0x01): # on
            self.write_cmd(cmd)
        self.fill(0)
        self.show()

    def poweroff(self):
        self.write_cmd(SET_DISP | 0x00)

    def contrast(self, contrast):
        self.write_cmd(SET_CONTRAST)
        self.write_cmd(contrast)

    def invert(self, invert):
        self.write_cmd(SET_NORM_INV | (invert & 1))

    def show(self):
        x0 = 0
        x1 = self.width - 1
        if self.width == 64:
            # displays with width of 64 pixels are shifted by 32
            x0 += 32
            x1 += 32
        self.write_cmd(SET_COL_ADDR)
        self.write_cmd(x0)
        self.write_cmd(x1)
        self.write_cmd(SET_PAGE_ADDR)
        self.write_cmd(0)
        self.write_cmd(self.pages - 1)
        self.write_framebuf()

    def fill(self, col):
        self.framebuf.fill(col)

    def pixel(self, x, y, col):
        self.framebuf.pixel(x, y, col)

    def scroll(self, dx, dy):
        self.framebuf.scroll(dx, dy)

    def text(self, string, x, y, col=1):
        self.framebuf.text(string, x, y, col)


class SSD1306_I2C(SSD1306):
    def __init__(self, width, height, i2c, addr=0x3c, external_vcc=False):
        self.i2c = i2c
        self.addr = addr
        self.temp = bytearray(2)
        # Add an extra byte to the data buffer to hold an I2C data/command byte
        # to use hardware-compatible I2C transactions.  A memoryview of the
        # buffer is used to mask this byte from the framebuffer operations
        # (without a major memory hit as memoryview doesn't copy to a separate
        # buffer).
        self.buffer = bytearray(((height // 8) * width) + 1)
        self.buffer[0] = 0x40  # Set first byte of data buffer to Co=0, D/C=1
        self.framebuf = framebuf.FrameBuffer1(memoryview(self.buffer)[1:], width, height)
        super().__init__(width, height, external_vcc)

    def write_cmd(self, cmd):
        self.temp[0] = 0x80 # Co=1, D/C#=0
        self.temp[1] = cmd
        self.i2c.writeto(self.addr, self.temp)

    def write_framebuf(self):
        # Blast out the frame buffer using a single I2C transaction to support
        # hardware I2C interfaces.
        self.i2c.writeto(self.addr, self.buffer)

    def poweron(self):
        pass


class SSD1306_SPI(SSD1306):
    def __init__(self, width, height, spi, dc, res, cs, external_vcc=False):
        self.rate = 10 * 1024 * 1024
        dc.init(dc.OUT, value=0)
        res.init(res.OUT, value=0)
        cs.init(cs.OUT, value=1)
        self.spi = spi
        self.dc = dc
        self.res = res
        self.cs = cs
        self.buffer = bytearray((height // 8) * width)
        self.framebuf = framebuf.FrameBuffer1(self.buffer, width, height)
        super().__init__(width, height, external_vcc)

    def write_cmd(self, cmd):
        self.spi.init(baudrate=self.rate, polarity=0, phase=0)
        self.cs.high()
        self.dc.low()
        self.cs.low()
        self.spi.write(bytearray([cmd]))
        self.cs.high()

    def write_framebuf(self):
        self.spi.init(baudrate=self.rate, polarity=0, phase=0)
        self.cs.high()
        self.dc.high()
        self.cs.low()
        self.spi.write(self.buffer)
        self.cs.high()

    def poweron(self):
        self.res.high()
        time.sleep_ms(1)
        self.res.low()
        time.sleep_ms(10)
        self.res.high()
