SSD1306 OLED with Arduino Mega 2560 R3

Wiring for the SSD1306 OLED 128x64 (I2C) on the Arduino Mega 2560 R3 (ATmega2560, 5 V logic), chosen with the same pin rules BoardPilot uses: default buses first, and no pins that are used for flash, USB, the debugger or booting.

Wiring

Check before you power it on

• Supply: 5 V from the 5V pin.
• I2C uses the board’s default pins SDA 20 (SDA) and SCL 21 (SCL). Most modules include pull-up resistors; if the part is not found, check them and swap-test SDA/SCL.

Test code (Arduino)

#include <Wire.h>

void setup() {
  Serial.begin(115200);
  Wire.begin();  // SDA = SDA 20, SCL = SCL 21 (the board's default I2C pins)
  Wire.beginTransmission(0x3C);
  bool found = Wire.endTransmission() == 0;
  Serial.println(found ? "SSD1306 OLED 128x64 (I2C) found at 0x3C" : "Not found: check power, GND and SDA/SCL");
}

void loop() {}

Arduino board: arduino:avr:mega.

Questions

Which Arduino Mega 2560 R3 pins do I use for the SSD1306 OLED?

GND → GND, VCC → 5V, SCL → SCL 21 (PD0), SDA → SDA 20 (PD1).

Does the SSD1306 OLED work with the Arduino Mega 2560 R3 at 5 V?

Yes: the SSD1306 OLED runs at 3.3-5 V and the Arduino Mega 2560 R3 uses 5 V signals, so no level shifting is needed.

What is the I2C address of the SSD1306 OLED?

0x3C or 0x3D. An I2C scan (BoardPilot does it for you) shows which one your module uses.

Full Arduino Mega 2560 R3 pinout · SSD1306 OLED 128x64 (I2C): all pins and data

The SSD1306 OLED on other boards

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