How to Use OLED Displays with ESP32 Boards
Hello and welcome back! In this tutorial, we will learn how to use the OLED display with an ESP32 board. With this knowledge, you can create OLED-based projects and explore the potential of this technology. For this tutorial, I used the 128*64 OLED display. OLED displays have several advantages over other display technologies, including fast response time, high contrast, high brightness, wide viewing angles, and being thin and flexible. These advantages make OLED displays ideal for a wide range of applications that require high image quality and energy efficiency. Therefore, I believe this tutorial is most important for you. If you want to learn more about OLED displays, please use this link.
Ok, let’s do it step by step. The required components are given below.
- ESP32 board x 1 — Our Store / Amazon
- OLED display x 1 — Our Store / Amazon
- Breadboard x 1 — Our Store / Amazon
- Jumper wires — Our Store / Amazon
Disclosure: These Amazon links are Affiliate links. As an Amazon Associate, I earn from qualifying purchases.
Step 1
Firstly, identify these components.
Step 2
Secondly, place the ESP32 board on the breadboard.
Step 3
Thirdly, connect the OLED display to the ESP32 board. For that, use the circuit diagram below.
Step 4
Now, connect the ESP32 board to the computer using a USB cable.
Step 5
OK, now let’s upload a simple program to the ESP32 board. For that, follow the instructions below.
- First, include the library files to the Arduino IDE.
- For that, open the Arduino IDE and go to Sketch > Include Library > Manage Libraries. Search for “Adafruit GFX” and “Adafruit SSD1306” and install them.
- Now copy and paste the below program into the Arduino IDE.
- Code and circuit diagram — Download
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#define OLED_ADDR 0x3C
Adafruit_SSD1306 display(128, 64, &Wire, -1);
void setup() {
display.begin(SSD1306_SWITCHCAPVCC, OLED_ADDR);
display.clearDisplay();
display.setTextColor(WHITE);
display.setTextSize(2);
display.setCursor(20, 20);
display.println("SriTu Hobby");
display.display();
}
void loop() {}
- Next, select the board and port. And then click the upload button.
- Now, press and hold the boot button for two seconds while the following message is displayed.
Step 6
After the code is uploaded, remove the USB cable and power the ESP32 board using an external power source. But, you can use USB power. Now, you can show text on the display.
Step 7
And then, you can try the code below. It included advanced code patterns.
- Code and circuit diagram — Download
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
#define OLED_RESET 4
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
#define NUMFLAKES 10 // Number of snowflakes in the animation example
#define LOGO_HEIGHT 16
#define LOGO_WIDTH 16
static const unsigned char PROGMEM logo_bmp[] =
{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
};
void setup() {
display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
display.display();
delay(2000);
}
void loop() {
// intro();
testdrawline(); // Draw many lines
testdrawrect(); // Draw rectangles (outlines)
testfillrect(); // Draw rectangles (filled)
testdrawcircle(); // Draw circles (outlines)
testfillcircle(); // Draw circles (filled)
testdrawroundrect(); // Draw rounded rectangles (outlines)
testfillroundrect(); // Draw rounded rectangles (filled)
testdrawtriangle(); // Draw triangles (outlines)
testfilltriangle(); // Draw triangles (filled)
testdrawbitmap(); // Draw a small bitmap image
testanimate(logo_bmp, LOGO_WIDTH, LOGO_HEIGHT); // Animate bitmaps
}
void intro() {
display.clearDisplay();
display.setTextSize(2);
display.setTextColor(SSD1306_WHITE);
display.setCursor(40, 0);
display.println(F("OLED"));
display.setCursor(20, 20);
display.println(F("Display"));
display.setCursor(15, 40);
display.println(F("Tutorial"));
display.display();// Show initial text
delay(100);
// Scroll in various directions, pausing in-between:
display.startscrollright(0x00, 0x0F);
delay(2000);
display.stopscroll();
delay(1000);
display.startscrollleft(0x00, 0x0F);
delay(2000);
display.stopscroll();
delay(1000);
display.startscrolldiagright(0x00, 0x07);
delay(2000);
display.startscrolldiagleft(0x00, 0x07);
delay(2000);
display.stopscroll();
delay(1000);
}
void testdrawline() {
int16_t i;
display.clearDisplay(); // Clear display buffer
for (i = 0; i < display.width(); i += 4) {
display.drawLine(0, 0, i, display.height() - 1, SSD1306_WHITE);
display.display(); // Update screen with each newly-drawn line
delay(1);
}
for (i = 0; i < display.height(); i += 4) {
display.drawLine(0, 0, display.width() - 1, i, SSD1306_WHITE);
display.display();
delay(1);
}
delay(250);
display.clearDisplay();
for (i = 0; i < display.width(); i += 4) {
display.drawLine(0, display.height() - 1, i, 0, SSD1306_WHITE);
display.display();
delay(1);
}
for (i = display.height() - 1; i >= 0; i -= 4) {
display.drawLine(0, display.height() - 1, display.width() - 1, i, SSD1306_WHITE);
display.display();
delay(1);
}
delay(250);
display.clearDisplay();
for (i = display.width() - 1; i >= 0; i -= 4) {
display.drawLine(display.width() - 1, display.height() - 1, i, 0, SSD1306_WHITE);
display.display();
delay(1);
}
for (i = display.height() - 1; i >= 0; i -= 4) {
display.drawLine(display.width() - 1, display.height() - 1, 0, i, SSD1306_WHITE);
display.display();
delay(1);
}
delay(250);
display.clearDisplay();
for (i = 0; i < display.height(); i += 4) {
display.drawLine(display.width() - 1, 0, 0, i, SSD1306_WHITE);
display.display();
delay(1);
}
for (i = 0; i < display.width(); i += 4) {
display.drawLine(display.width() - 1, 0, i, display.height() - 1, SSD1306_WHITE);
display.display();
delay(1);
}
delay(2000); // Pause for 2 seconds
}
void testdrawrect(void) {
display.clearDisplay();
for (int16_t i = 0; i < display.height() / 2; i += 2) {
display.drawRect(i, i, display.width() - 2 * i, display.height() - 2 * i, SSD1306_WHITE);
display.display(); // Update screen with each newly-drawn rectangle
delay(1);
}
delay(2000);
}
void testfillrect(void) {
display.clearDisplay();
for (int16_t i = 0; i < display.height() / 2; i += 3) {
// The INVERSE color is used so rectangles alternate white/black
display.fillRect(i, i, display.width() - i * 2, display.height() - i * 2, SSD1306_INVERSE);
display.display(); // Update screen with each newly-drawn rectangle
delay(1);
}
delay(2000);
}
void testdrawcircle(void) {
display.clearDisplay();
for (int16_t i = 0; i < max(display.width(), display.height()) / 2; i += 2) {
display.drawCircle(display.width() / 2, display.height() / 2, i, SSD1306_WHITE);
display.display();
delay(1);
}
delay(2000);
}
void testfillcircle(void) {
display.clearDisplay();
for (int16_t i = max(display.width(), display.height()) / 2; i > 0; i -= 3) {
// The INVERSE color is used so circles alternate white/black
display.fillCircle(display.width() / 2, display.height() / 2, i, SSD1306_INVERSE);
display.display(); // Update screen with each newly-drawn circle
delay(1);
}
delay(2000);
}
void testdrawroundrect(void) {
display.clearDisplay();
for (int16_t i = 0; i < display.height() / 2 - 2; i += 2) {
display.drawRoundRect(i, i, display.width() - 2 * i, display.height() - 2 * i,
display.height() / 4, SSD1306_WHITE);
display.display();
delay(1);
}
delay(2000);
}
void testfillroundrect(void) {
display.clearDisplay();
for (int16_t i = 0; i < display.height() / 2 - 2; i += 2) {
// The INVERSE color is used so round-rects alternate white/black
display.fillRoundRect(i, i, display.width() - 2 * i, display.height() - 2 * i,
display.height() / 4, SSD1306_INVERSE);
display.display();
delay(1);
}
delay(2000);
}
void testdrawtriangle(void) {
display.clearDisplay();
for (int16_t i = 0; i < max(display.width(), display.height()) / 2; i += 5) {
display.drawTriangle(
display.width() / 2 , display.height() / 2 - i,
display.width() / 2 - i, display.height() / 2 + i,
display.width() / 2 + i, display.height() / 2 + i, SSD1306_WHITE);
display.display();
delay(1);
}
delay(2000);
}
void testfilltriangle(void) {
display.clearDisplay();
for (int16_t i = max(display.width(), display.height()) / 2; i > 0; i -= 5) {
// The INVERSE color is used so triangles alternate white/black
display.fillTriangle(
display.width() / 2 , display.height() / 2 - i,
display.width() / 2 - i, display.height() / 2 + i,
display.width() / 2 + i, display.height() / 2 + i, SSD1306_INVERSE);
display.display();
delay(1);
}
delay(2000);
}
void testdrawbitmap(void) {
display.clearDisplay();
display.drawBitmap(
(display.width() - LOGO_WIDTH ) / 2,
(display.height() - LOGO_HEIGHT) / 2,
logo_bmp, LOGO_WIDTH, LOGO_HEIGHT, 1);
display.display();
delay(1000);
}
#define XPOS 0 // Indexes into the 'icons' array in function below
#define YPOS 1
#define DELTAY 2
void testanimate(const uint8_t *bitmap, uint8_t w, uint8_t h) {
int8_t f, icons[NUMFLAKES][3];
// Initialize 'snowflake' positions
for (f = 0; f < NUMFLAKES; f++) {
icons[f][XPOS] = random(1 - LOGO_WIDTH, display.width());
icons[f][YPOS] = -LOGO_HEIGHT;
icons[f][DELTAY] = random(1, 6);
Serial.print(F("x: "));
Serial.print(icons[f][XPOS], DEC);
Serial.print(F(" y: "));
Serial.print(icons[f][YPOS], DEC);
Serial.print(F(" dy: "));
Serial.println(icons[f][DELTAY], DEC);
}
for (;;) { // Loop forever...
display.clearDisplay(); // Clear the display buffer
// Draw each snowflake:
for (f = 0; f < NUMFLAKES; f++) {
display.drawBitmap(icons[f][XPOS], icons[f][YPOS], bitmap, w, h, SSD1306_WHITE);
}
display.display(); // Show the display buffer on the screen
delay(200); // Pause for 1/10 second
// Then update coordinates of each flake...
for (f = 0; f < NUMFLAKES; f++) {
icons[f][YPOS] += icons[f][DELTAY];
// If snowflake is off the bottom of the screen...
if (icons[f][YPOS] >= display.height()) {
// Reinitialize to a random position, just off the top
icons[f][XPOS] = random(1 - LOGO_WIDTH, display.width());
icons[f][YPOS] = -LOGO_HEIGHT;
icons[f][DELTAY] = random(1, 6);
}
}
}
}
- Now, select board and port. After, click the upload button.
- Now, press and hold the boot button for two seconds while the following message is displayed.
OK, now you can see the output on the OLED display. The full video guide is below. We hope to see you in our upcoming projects and tutorials.
How to Use OLED Displays with ESP32 Boards