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 kits:
| 1 | × | DIYables Sensor Kit (30 sensors/displays) | |
| 1 | × | DIYables Sensor Kit (18 sensors/displays) |
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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:
- Raspberry Pi - OLED tutorial
- Raspberry Pi - Ultrasonic Sensor tutorial
Wiring Diagram
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
- Prior to utilizing the OLED display with a Raspberry Pi, we need to enable I2C interface on Raspberry Pi. See How to enable I2C interface on Raspberry Pi
- Install the OLED library by running the following command:
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.