Read from Ultrasonic Module

In this project, we use ultrasonic sensors to measure distance and display the readings on the I2C LCD1602.

Steps

1. In this project, an I2C LCD1602 is used, so it’s necessary to download the relevant libraries to make it work.

   cd ~/
   wget https://github.com/sunfounder/raphael-kit/blob/master/python/LCD1602.py
   

2. Install smbus2 for I2C.

   sudo pip3 install smbus2
   

3. Save the following code to your Raspberry Pi and give it a name, for example, ultrasonic.ty.

   from robot_hat import ADC, Ultrasonic, Pin
   import LCD1602
   import time
   
   # Create ADC object for photoresistor
   a0 = ADC(0)
   
   # Create Ultrasonic object
   us = Ultrasonic(Pin("D2"), Pin("D3")) //Trig to digital pin 2, echo to pin 3
   
   def setup():
       # Initialize LCD1602
       LCD1602.init(0x27, 1)
       # Initial message on LCD
       LCD1602.write(0, 0, 'Measuring...')
       time.sleep(2)
   
   def destroy():
       # Clear the LCD display
       LCD1602.clear()
   
   def loop():
       while True:
           # Read distance from ultrasonic sensor
           distance = us.read()
           # Display the distance on the LCD
           if distance != -1:
               # Display the valid distance on the LCD
               LCD1602.write(0, 0, 'Dist: %.2f cm   ' % distance)
   
           # Update every 0.5 seconds
           time.sleep(0.2)
   
   if __name__ == '__main__':
       setup()
       try:
           loop()
       except KeyboardInterrupt:
           destroy()
       except Exception as e:
           # Clear the LCD and print error message in case of an exception
           destroy()
           print("Error:", e)
   

4. Use the command sudo python3 ultrasonic.ty to run this code.