import machine 
from machine import SoftI2C, Pin 
from lcd_api import LcdApi 
from i2c_lcd import I2cLcd
from ssd1306 import SSD1306_I2C
from hcsr04 import HCSR04
from time import sleep


sensor = HCSR04(trigger_pin=5, echo_pin=18, echo_timeout_us=10000)

I2C_ADDR_LCD = 0x27
I2C_ADDR_OLED = 0x3c
oled_width = 128
oled_height = 64 
lcd_Rows = 2 
lcd_Columns = 16

i2c = SoftI2C(scl=Pin(22), sda=Pin(21), freq=10000) 	#initializing the I2C method for ESP32 

lcd = I2cLcd(i2c, I2C_ADDR_LCD, lcd_Rows, lcd_Columns)
oled = SSD1306_I2C(oled_width, oled_height, i2c, I2C_ADDR_OLED)

lcd.move_to(1,0)
lcd.putstr("ESP32 with LCD")

oled.text('ESP32 with OLED', 3, 6, 1)
oled.show()

while True:
    distance = sensor.distance_cm()
    print('Distance:', distance, 'cm')
    lcd.move_to(0,1)
    lcd.putstr('Distance: '+str(distance))
    oled.text('distance:'+str(distance), 0, 26, 1)
    oled.show()
    oled.fill(0)    #to clear the screen

    sleep(1)

main.py

diagram.json

import machine, time
from machine import Pin

__version__ = '0.2.0'
__author__ = 'Roberto Sánchez'
__license__ = "Apache License 2.0. https://www.apache.org/licenses/LICENSE-2.0"

class HCSR04:
    """
    Driver to use the untrasonic sensor HC-SR04.
    The sensor range is between 2cm and 4m.
    The timeouts received listening to echo pin are converted to OSError('Out of range')
    """
    # echo_timeout_us is based in chip range limit (400cm)
    #500*2*30
    def __init__(self, trigger_pin, echo_pin, echo_timeout_us=500*2*30):
        """
        trigger_pin: Output pin to send pulses
        echo_pin: Readonly pin to measure the distance. The pin should be protected with 1k resistor
        echo_timeout_us: Timeout in microseconds to listen to echo pin. 
        By default is based in sensor limit range (4m)
        """
        self.echo_timeout_us = echo_timeout_us
        # Init trigger pin (out)
        self.trigger = Pin(trigger_pin, mode=Pin.OUT, pull=None)
        self.trigger.value(0)

        # Init echo pin (in)
        self.echo = Pin(echo_pin, mode=Pin.IN, pull=None)

    def _send_pulse_and_wait(self):
        """
        Send the pulse to trigger and listen on echo pin.
        We use the method `machine.time_pulse_us()` to get the microseconds until the echo is received.
        """
        self.trigger.value(0) # Stabilize the sensor
        time.sleep_us(5)
        self.trigger.value(1)
        # Send a 10us pulse.
        time.sleep_us(10)
        self.trigger.value(0)
        try:
            pulse_time = machine.time_pulse_us(self.echo, 1, self.echo_timeout_us)
            return pulse_time
        except OSError as ex:
            if ex.args[0] == 110: # 110 = ETIMEDOUT
                raise OSError('Out of range')
            raise ex

    def distance_mm(self):
        """
        Get the distance in milimeters without floating point operations.
        """
        pulse_time = self._send_pulse_and_wait()

        # To calculate the distance we get the pulse_time and divide it by 2 
        # (the pulse walk the distance twice) and by 29.1 becasue
        # the sound speed on air (343.2 m/s), that It's equivalent to
        # 0.34320 mm/us that is 1mm each 2.91us
        # pulse_time // 2 // 2.91 -> pulse_time // 5.82 -> pulse_time * 100 // 582 
        mm = pulse_time * 100 // 582
        return mm

    def distance_cm(self):
        """
        Get the distance in centimeters with floating point operations.
        It returns a float
        """
        pulse_time = self._send_pulse_and_wait()

        # To calculate the distance we get the pulse_time and divide it by 2 
        # (the pulse walk the distance twice) and by 29.1 becasue
        # the sound speed on air (343.2 m/s), that It's equivalent to
        # 0.034320 cm/us that is 1cm each 29.1us
        cms = (pulse_time / 2) / 29.4
        return cms

hcsr04.py

"""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

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()

i2c_lcd.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()