import network
from machine import I2C, Pin
from i2c_lcd import I2cLcd
from time import sleep
from hcsr04 import HCSR04

# Pin definitions
TRIGGER_PIN = 23
ECHO_PIN = 19
BUTTON_PIN = 5
BUTTON_N_PIN = 18
LED_PIN = 4
LED_N_PIN = 2
LED_NN_PIN = 15
LCD_SCL_PIN = 22
LCD_SDA_PIN = 21
LCD_ADDRESS = 0x27

# Initialize hardware objects
sensor = HCSR04(trigger_pin=TRIGGER_PIN, echo_pin=ECHO_PIN)
led = Pin(LED_PIN, Pin.OUT)
led_n = Pin(LED_N_PIN, Pin.OUT)
led_nn = Pin(LED_NN_PIN, Pin.OUT)
button = Pin(BUTTON_PIN, Pin.IN, Pin.PULL_UP)
button_n = Pin(BUTTON_N_PIN, Pin.IN, Pin.PULL_UP)
i2c = I2C(scl=Pin(LCD_SCL_PIN), sda=Pin(LCD_SDA_PIN), freq=400000)
lcd = I2cLcd(i2c, LCD_ADDRESS, 2, 16)

# Initialize LCD screen
lcd.move_to(3, 0)
lcd.putstr('Micropython')
sleep(2)
lcd.move_to(3, 0)
lcd.putstr('cam on ban ')
lcd.move_to(0, 1)
lcd.putstr("hello fschooler")

# Main loop
while True:
	distance = sensor.distance_cm()
	print(distance)
	sleep(0.1)

    # Control LED_NN based on distance
	if distance <= 100:
		led_nn.value(1)
	else:
		led_nn.value(0)

    # Control LED based on button
	button_status = button.value()
	if button_status == 0 and button_status != prev_button_status:
		led.value(not led.value())
	prev_button_status = button_status

    # Control LED_N based on button_n
	button_n_status = button_n.value()
	if button_n_status == 0 and button_n_status != prev_button_n_status:
		led_n.value(not led_n.value())
	prev_button_n_status = button_n_status
	sleep(0.1)



main.py

diagram.json

from machine import Pin, time_pulse_us
from utime import sleep_us

__version__ = '0.2.1'
__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)
    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
        sleep_us(5)
        self.trigger.value(1)
        # Send a 10us pulse.
        sleep_us(10)
        self.trigger.value(0)
        try:
            pulse_time = time_pulse_us(self.echo, 1, self.echo_timeout_us)
            # time_pulse_us returns -2 if there was timeout waiting for condition; and -1 if there was timeout during the main measurement. It DOES NOT raise an exception
            # ...as of MicroPython 1.17: http://docs.micropython.org/en/v1.17/library/machine.html#machine.time_pulse_us
            if pulse_time < 0:
                MAX_RANGE_IN_CM = const(500) # it's really ~400 but I've read people say they see it working up to ~460
                pulse_time = int(MAX_RANGE_IN_CM * 29.1) # 1cm each 29.1us
            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) / 29.1
        return cms

hcsr04.py

"""Implements a HD44780 character LCD connected via PCF8574 on I2C. 
   This was tested with: https://www.wemos.cc/product/d1-mini.html""" 
from lcd_api import LcdApi 
from machine import I2C 
from time import sleep_ms 
# The PCF8574 has a jumper selectable address: 0x20 - 0x27 
#DEFAULT_I2C_ADDR = 0x20 
# Defines shifts or masks for the various LCD line attached to the PCF8574 
MASK_RS = 0x01 
MASK_RW = 0x02 
MASK_E = 0x04 
SHIFT_BACKLIGHT = 3 
SHIFT_DATA = 4 
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, bytearray([0])) 
        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) 
        # Put LCD into 4 bit mode 
        self.hal_write_init_nibble(self.LCD_FUNCTION) 
        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) 
    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, bytearray([byte | MASK_E])) 
        self.i2c.writeto(self.i2c_addr, bytearray([byte])) 
    def hal_backlight_on(self): 
        """Allows the hal layer to turn the backlight on.""" 
        self.i2c.writeto(self.i2c_addr, bytearray([1 << SHIFT_BACKLIGHT])) 
    def hal_backlight_off(self): 
        """Allows the hal layer to turn the backlight off.""" 
        self.i2c.writeto(self.i2c_addr, bytearray([0])) 
    def hal_write_command(self, cmd): 
        """Writes 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, bytearray([byte | MASK_E])) 
        self.i2c.writeto(self.i2c_addr, bytearray([byte])) 
        byte = ((self.backlight << SHIFT_BACKLIGHT) | ((cmd & 0x0f) << SHIFT_DATA)) 
        self.i2c.writeto(self.i2c_addr, bytearray([byte | MASK_E])) 
        self.i2c.writeto(self.i2c_addr, bytearray([byte])) 
        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.""" 
        byte = (MASK_RS | (self.backlight << SHIFT_BACKLIGHT) | (((data >> 4) & 0x0f) << SHIFT_DATA)) 
        self.i2c.writeto(self.i2c_addr, bytearray([byte | MASK_E])) 
        self.i2c.writeto(self.i2c_addr, bytearray([byte])) 
        byte = (MASK_RS | (self.backlight << SHIFT_BACKLIGHT) | ((data & 0x0f) << SHIFT_DATA)) 
        self.i2c.writeto(self.i2c_addr, bytearray([byte | MASK_E])) 
        self.i2c.writeto(self.i2c_addr, bytearray([byte]))

i2c_lcd.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 network
from machine import I2C, Pin
from i2c_lcd import I2cLcd
from time import sleep
from hcsr04 import HCSR04

# Pin definitions
TRIGGER_PIN = 23
ECHO_PIN = 19
BUTTON_PIN = 5
BUTTON_N_PIN = 18
LED_PIN = 4
LED_N_PIN = 2
LED_NN_PIN = 15
LCD_SCL_PIN = 22
LCD_SDA_PIN = 21
LCD_ADDRESS = 0x27
BLYNK_AUTH = "UIO29ZvSm8bzYR7KLNeXsDWTJ1K770jn"
blynk = BlynkLib.Blynk(BLYNK_AUTH)

# Initialize hardware objects
sensor = HCSR04(trigger_pin=TRIGGER_PIN, echo_pin=ECHO_PIN)
led = Pin(LED_PIN, Pin.OUT)
led_n = Pin(LED_N_PIN, Pin.OUT)
led_nn = Pin(LED_NN_PIN, Pin.OUT)
button = Pin(BUTTON_PIN, Pin.IN, Pin.PULL_UP)
button_n = Pin(BUTTON_N_PIN, Pin.IN, Pin.PULL_UP)
i2c = I2C(scl=Pin(LCD_SCL_PIN), sda=Pin(LCD_SDA_PIN), freq=400000)
lcd = I2cLcd(i2c, LCD_ADDRESS, 2, 16)

# Initialize LCD screen
lcd.move_to(3, 0)
lcd.putstr('Micropython')
sleep(2)
lcd.move_to(3, 0)
lcd.putstr('cam on ban ')
lcd.move_to(0, 1)
lcd.putstr("hello fschooler")

# Blynk
@blynk.on("V4") #virtual pin V4
def v4_read_handler(value): #read the value
	led.value(int(value[0])) #turn on/off the led based on value


@blynk.on("V5") #virtual pin V5
def v5_read_handler(value): #read the value
	led_n.value(int(value[0])) #turn on/off the led_n based on value


@blynk.on("V0") #virtual pin V0
def v0_read_handler(value): #read the value
	led_nn.value(int(value[0])) #turn on/off the led_nn based on value

# Main loop
while True:
	blynk.run()
	distance = sensor.distance_cm()
	print(distance)
	sleep(0.1)

    # Control LED_NN based on distance
	if distance <= 100:
		led_nn.value(1)
	else:
		led_nn.value(0)

    # Control LED based on button
	button_status = button.value()
	if button_status == 0 and button_status != prev_button_status:
		led.value(not led.value())
		blynk.virtual_write(4,1)
	prev_button_status = button_status

    # Control LED_N based on button_n
	button_n_status = button_n.value()
	if button_n_status == 0 and button_n_status != prev_button_n_status:
		led_n.value(not led_n.value())
		blynk.virtual_write(5,0)
	prev_button_n_status = button_n_status
	sleep(0.1)

