FREE SIMULATOR EXAMPLE · INTERMEDIATE

Raspberry Pi Pico: SSD1306 OLED (4-pin I2C)

This example drives a cheap 4-pin SSD1306 OLED module (GND/VCC/SCL/SDA) from the Raspberry Pi Pico over I2C — SDA on GP4, SCL on GP5. It shows “Hello sensbench!” in large text with a live counter, using the same Adafruit SSD1306 + GFX library stack you would use on real hardware.

Board	Raspberry Pi Pico (RP2040 dual-core Cortex-M0+, 133 MHz)
Difficulty	intermediate
Category	displays
Libraries	Adafruit SSD1306, Adafruit GFX Library
Runs in	Sensbench browser simulator — free, no account

The exact circuit you get when you open this example — already wired, ready to run.

The sketch

// Raspberry Pi Pico — SSD1306 128x64 OLED (4-pin I2C module)
// Wiring: SDA -> GP4  |  SCL -> GP5  |  VCC -> 3V3  |  GND -> GND
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

Adafruit_SSD1306 display(128, 64, &Wire, -1);
int n = 0;

void setup() {
  Serial.begin(115200);
  Wire.setSDA(4);
  Wire.setSCL(5);
  Wire.begin();
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println("SSD1306 not found!");
    while (true) delay(10);
  }
  display.clearDisplay();
  Serial.println("OLED ready");
}

void loop() {
  n++;
  display.clearDisplay();
  display.setTextSize(2);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.println("Hello");
  display.println("sensbench!");
  display.setTextSize(1);
  display.setCursor(0, 48);
  display.print("Count: ");
  display.print(n);
  display.display();
  delay(500);
}

How it works

The sketch explicitly sets the I2C pins with Wire.setSDA(4) and Wire.setSCL(5) before Wire.begin() — on the Pico the default I2C0 pins are GP4/GP5 anyway, but being explicit makes the wiring unambiguous. Then display.begin(SSD1306_SWITCHCAPVCC, 0x3C) initializes the 128×64 panel at the standard address.

The loop clears the display, prints “Hello” and “sensbench!” in 2x text, draws a 1x “Count: N” line that increments every 500 ms, and calls display.display() to push the buffer to the panel. The count is the visual proof that the loop is live — the OLED updates in place without flicker because the whole frame is rendered off-screen and blitted at once.

Before you build it for real

Get the parts

Related examples

FAQ

Why do I need the Adafruit GFX library?

The Adafruit_SSD1306 library drives the OLED controller, but it depends on Adafruit_GFX for the drawing primitives — text, lines, circles, rectangles. Together they are the de-facto standard stack for SSD1306 displays, and the same code runs on Arduino, ESP32, and Pico alike.

What does SSD1306_SWITCHCAPVCC mean?

It tells the library how the display is powered: SSD1306_SWITCHCAPVCC is the normal 3.3 V supply mode with the internal charge pump on. The display.begin() call fails — and the sketch hangs in the not-found loop — if the wiring or the address (0x3C here) is wrong.