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
Or you can buy the following sensor kits:
| 1 | × | DIYables Sensor Kit (30 sensors/displays) | |
| 1 | × | DIYables Sensor Kit (18 sensors/displays) |
Disclosure: Some of the links provided in this section are Amazon affiliate links. We may receive a commission for any purchases made through these links at no additional cost to you.
Additionally, some of these links are for products from our own brand, DIYables.
Additionally, some of these links are for products from our own brand, DIYables.
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
To simplify and organize your wiring setup, we recommend using a Screw Terminal Block Shield for Raspberry Pi. This shield ensures more secure and manageable connections, as shown below:
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.