Raspberry Pi - Ultrasonic Sensor - OLED

This tutorial instructs you how to measure the distance using an ultrasonic sensor and then displaying it on an OLED.

Hardware Preparation

1×Raspberry Pi 4 Model B
1×SSD1306 I2C OLED Display 128x64
1×Ultrasonic Sensor
1×Breadboard
1×Jumper Wires
1×(Optional) Screw Terminal Adapter for Raspberry Pi

Or you can buy the following sensor kit:

1×DIYables Sensor Kit 30 types, 69 units
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Overview of OLED and Ultrasonic Sensor

If you are unfamiliar with OLED and Ultrasonic Sensor (including pinout, functioning, programming, etc.), the following tutorials can help:

Wiring Diagram

The wiring diagram between Raspberry Pi and Ultrasonic Sensor OLED

This image is created using Fritzing. Click to enlarge image

Raspberry Pi Code - Ultrasonic Sensor - OLED

Detailed Instructions

  • Make sure you have Raspbian or any other Raspberry Pi compatible operating system installed on your Pi.
  • Make sure your Raspberry Pi is connected to the same local network as your PC.
  • Make sure your Raspberry Pi is connected to the internet if you need to install some libraries.
  • If this is the first time you use Raspberry Pi, See how to set up the Raspberry Pi
  • Connect your PC to the Raspberry Pi via SSH using the built-in SSH client on Linux and macOS or PuTTY on Windows. See to how connect your PC to Raspberry Pi via SSH.
  • Make sure you have the RPi.GPIO library installed. If not, install it using the following command:
sudo apt-get update sudo apt-get install python3-rpi.gpio
pip install Adafruit-SSD1306
  • Create a Python script file ultrasonic_oled.py and add the following code:
# This Raspberry Pi code was developed by newbiely.com # This Raspberry Pi code is made available for public use without any restriction # For comprehensive instructions and wiring diagrams, please visit: # https://newbiely.com/tutorials/raspberry-pi/raspberry-pi-ultrasonic-sensor-oled import time import RPi.GPIO as GPIO import Adafruit_SSD1306 # GPIO pin configuration for the ultrasonic sensor TRIG_PIN = 16 ECHO_PIN = 20 # OLED display configuration OLED_RESET_PIN = None # Set to GPIO pin if your display has a reset pin OLED = Adafruit_SSD1306.SSD1306_128_64(rst=OLED_RESET_PIN) # Initialize the OLED display OLED.begin() # Clear the display OLED.clear() OLED.display() def measure_distance(): # Trigger the ultrasonic sensor GPIO.output(TRIG_PIN, True) time.sleep(0.00001) GPIO.output(TRIG_PIN, False) pulse_start, pulse_end = 0, 0 # Record the time when the ultrasonic wave is transmitted while GPIO.input(ECHO_PIN) == 0: pulse_start = time.time() # Record the time when the reflected wave is received while GPIO.input(ECHO_PIN) == 1: pulse_end = time.time() # Calculate the time duration of the pulse pulse_duration = pulse_end - pulse_start # Calculate the distance using the speed of sound (343 m/s) distance = pulse_duration * 17150 return round(distance, 2) try: # Set up GPIO GPIO.setmode(GPIO.BCM) GPIO.setup(TRIG_PIN, GPIO.OUT) GPIO.setup(ECHO_PIN, GPIO.IN) while True: # Read distance from ultrasonic sensor distance = measure_distance() # Clear the display OLED.clear() # Display distance on OLED OLED.draw.text((0, 0), "Distance:", font=None, fill=255) OLED.draw.text((0, 16), "{} cm".format(distance), font=None, fill=255) # Display on OLED OLED.display() # Print distance to console (optional) print("Distance: {} cm".format(distance)) # Delay for readability time.sleep(1) except KeyboardInterrupt: print("Program terminated by user.") finally: GPIO.cleanup()
  • Save the file and run the Python script by executing the following command in the terminal:
python3 ultrasonic_oled.py

The script runs in an infinite loop continuously until you press Ctrl + C in the terminal.

  • Move your hand in front of the sensor.
  • Check out the result on the OLED and the Serial Monitor.

※ NOTE THAT:

This code will align the text on an OLED display both horizontally and vertically. For more information, please refer to How to vertical/horizontal center on OLED.

Video Tutorial