A little intro
Let's Start with OLED Displays
Install Arduino libraries
Wiring the WaveShare OLED Display (SPI Mode) with PH2.0 7pin connector
Testing the OLED display
Ultrasonic Sensor Setup
Logic and Calculations for Ultrasonic Sensor
Helpful Resources

Published May 16, 2024

Arduino OLED Eye Movement with Sensors

Eye movements on an OLED display using an ultrasonic sensor and an Arduino. The setup simulates a pair of eyes that track obj movement

BeginnerFull instructions provided788

Things used in this project

Hardware components

Arduino UNO

WaveShare 1.5inch RGB OLED Display

Breadboard (generic)

Ultrasonic Sensor - HC-SR04 (Generic)

PH2.0 7pin connector

Software apps and online services

Arduino IDE

Story

A little intro:

In an age where interactive technology are becoming increasingly integrated into our daily lives, creating engaging and visually appealing projects can make the learning process both enjoyable and informative. With this in mind, I embarked on building something cute and interactive—a pair of animated eyes that follow the movement of an object using an OLED display and an ultrasonic sensor. The project leverages the power of an Arduino Uno microcontroller, a SSD1351 OLED display, and an HC-SR04 ultrasonic sensor to create a pair of eyes that track the presence and position of an object, such as a finger, in front of the sensor.

Let's Start with OLED Displays

Organic light-emitting diode (OLED) displays are relatively new technology, increasingly used in TVs, computer monitors, smartphones, and handheld game consoles. Unlike LCDs, which require backlighting, each OLED pixel generates its own light providing superior contrast and color control.

We will be using the RGB OLED displays from along with using AdaFruit display control and graphics libraries. To do so, we need to install some libraries.

Install Arduino libraries

To use the OLED display, we need two libraries from Adafruit into our IDE:

#include "Adafruit_GFX.h"

The Adafruit_GFX library is a core graphics library provided by Adafruit. It offers a wide range of graphics functions that simplify drawing shapes, text, and images on various displays. Key features of the Adafruit_GFX library include:

Drawing Shapes: Functions to draw basic shapes like lines, circles, rectangles, and triangles.
Text Rendering: Functions to render text with different fonts, sizes, and colors.
Bitmap Images: Functions to display bitmap images.
Coordinate System: Provides an easy-to-use coordinate system for positioning graphics elements on the screen.

#include "Adafruit_SSD1351.h"

Fortunately, the Arduino IDE makes library installation easy. Take a lookie!

Wiring the WaveShare OLED Display (SPI Mode) with PH2.0 7pin connector

Once you’ve installed the requisite libraries, you’re ready to wire up the display!

The WaveShare 1.5inch RGB OLED Display (SSD1351) uses a SSD1351 driver and the accompanying library provides the SPI (Serial Peripheral Interface) communication method, which requires specific wiring. Here's the general way to wire it up:

For the SPI connection, you’ll need to connect the OLED display to your Arduino as follows:

VCC: Connect to Arduino 5V
GND: Connect to Arduino GND
DIN (MOSI): Connect to Arduino digital pin 11 (MOSI)
CLK (SCK): Connect to Arduino digital pin 13 (SCK)
CS: Connect to Arduino digital pin 10
DC: Connect to Arduino digital pin 7
RST: Connect to Arduino digital pin 8

*please make sure you install the correct driver - had a bit of a hiccup with the display until I realized my errors!* :, )

Testing the OLED display

Once you’ve wired the OLED display, we’re ready to test it with some code!

I ended up going through a tutorial on creating the shapes (resourced below) and getting to learn how the coordinate system works with the pixels + dynamic graphics (gotta love loops). There are examples that iterates through a variety of drawing demonstrations, including: drawing lines, outlining and filling rectangles, circles, rounded rectangles, and triangles, rendering text with different styles, and drawing and animating bitmaps.

Here's the link for the tutorial: https://learn.adafruit.com/adafruit-gfx-graphics-library/graphics-primitives

Ultrasonic Sensor Setup

you’ll need to connect the sensor to your Arduino as follows:

GND: Arduino GND
Echo: Arduino digital pin 6
TRIG: Arduino digital pin 5
VCC: Arduino 5V

The overall schematic should look like this:

+5V         +---------+
      |          |         |
     OLED Display| Arduino |
     VCC  -------|    5V   |
                -|         |
     GND  -------|    GND  |
                -|         |
    DIN  ------- |   11    |
                -|         |
    CLK  ------- |   13    |
                -|         |
     CS  ------- |   10    |
                -|         |
     DC  ------- |    7    |
                -|         |
    RST  ------- |    8    |
                -|         |
                |         |
                +---------+
                  Ultrasonic
                    Sensor
     +5V        +---------+
      |         |         |
     TRIG  -----|    6   |
                -|         |
     ECHO  -----|    5    |
                -|         |
     GND  ----- |   GND   |
                |         |
                +---------+

Logic and Calculations for Ultrasonic Sensor

Sensor Setup:

The ultrasonic sensor has two main components: a transmitter (trigger) and a receiver (echo). The trigger sends out a sound wave, and the echo receives the wave after it bounces off an object.

Measuring Distance:

To measure the distance, we need to send a pulse from the trigger, wait for the echo to receive the reflected pulse, and calculate the time it took for the round trip.

The formula to calculate the distance is:

Distance=Duration×Speed of Sound / 2

The speed of sound is approximately 343 meters per second or 0.034 cm per microsecond. We divide by 2 to account for the sound traveling to the object and back.

Mapping Distance to Eye Movement:

The distance measured by the ultrasonic sensor is mapped to a range of eye movement. For example, a distance of 0 to 200 cm might correspond to a range of -30 to 30 pixels for the eyes' position.

The map function in Arduino helps to convert the distance to the required range for eye movement:

eyeOffset=map(distance, 0, 200, −30, 30

Make sure the wiring + libraries are correctly installed, you should be able to run and execute the program successfully! :)

Helpful Resources

OLED Arduino Display

AdaFruit GFX Library

SSD1351 Datasheet

SPI Communication Protocal Intro

Code

Main Program

#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1351.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 128

#define SCLK_PIN 13
#define MOSI_PIN 11
#define RST_PIN   8
#define DC_PIN    7
#define CS_PIN    10

#define BLACK 0x0000
#define WHITE 0xFFFF
#define BLUE 0x001F

#define TRIGGER_PIN 6
#define ECHO_PIN 5

unsigned long duration;
int distance;


Adafruit_SSD1351 display = Adafruit_SSD1351(SCREEN_WIDTH, SCREEN_HEIGHT, &SPI, CS_PIN, DC_PIN, RST_PIN);

void setup() {
  Serial.begin(9600);
  pinMode(TRIGGER_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  delay(250);
  display.begin();
  display.fillScreen(BLUE); // Clear the screen
}

void loop() {
  // Ultrasonic sensor code
  digitalWrite(TRIGGER_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIGGER_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIGGER_PIN, LOW);
  duration = pulseIn(ECHO_PIN, HIGH);
  distance = duration * 0.034 / 2;

  // Adjust eye position based on sensor readings
  int eyeOffset = map(distance, 0, 200, -30, 30); // Map sensor range to eye movement range
  int leftEyeX = display.width() / 2 - 25 + eyeOffset;
  int rightEyeX = display.width() / 2 + 25 + eyeOffset;

  Serial.print("Distance: ");
  Serial.println(distance);
  Serial.print("Eye offset: ");
  Serial.println(eyeOffset);

  // Display eyes
  display.fillCircle(leftEyeX, display.height() / 2, 15, WHITE);
  display.fillCircle(rightEyeX, display.height() / 2, 15, WHITE);
  delay(100); // Adjust delay as needed
  display.fillScreen(BLUE); // Clear the screen
}

Arduino OLED Eye Movement with Sensors

Things used in this project

Hardware components

Software apps and online services

Story

A little intro:

Let's Start with OLED Displays

Install Arduino libraries

Wiring the WaveShare OLED Display (SPI Mode) with PH2.0 7pin connector

Testing the OLED display

Ultrasonic Sensor Setup

Logic and Calculations for Ultrasonic Sensor

Helpful Resources

Schematics

Circuit Diagram

Hardware Schematic

Code

Main Program

Credits

Comments

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Arduino OLED Eye Movement with Sensors

Arduino OLED Eye Movement with Sensors

Things used in this project

Hardware components

Software apps and online services

Story

A little intro:

Let's Start with OLED Displays

Install Arduino libraries

Wiring the WaveShare OLED Display (SPI Mode) with PH2.0 7pin connector

Testing the OLED display

Ultrasonic Sensor Setup

Logic and Calculations for Ultrasonic Sensor

Helpful Resources

Schematics

Circuit Diagram

Hardware Schematic

Code

Main Program

Credits

Comments

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