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I2C Interface

Interface Overview​

The I2C (Inter-Integrated Circuit) interface is an efficient, low-cost two-wire serial bus. It uses a clock line (SCL) and a data line (SDA) for communication between a host chip and multiple peripherals. I2C supports multiple devices on the same bus, uses few pins, and is easy to extend. It is widely used with sensors, EEPROM, display modules, and other low-speed peripherals.

Case Objective​

Control a display through the I2C interface.

Required Hardware​

  • RDK X5 development board

  • Female-to-female jumper wires

  • I2C OLED display

Hardware Connection​

Connection diagram

Pin Mapping​

OLED pinBoard pinFunction
VCC1Power
GND39Ground
SDA3I2C data
SCL5I2C clock

40-Pin Header Definition​

40-pin header definition

Sample Code​

Install Dependencies​

# Install the package
pip install luma.oled

Create i2c_display.py​

Create an i2c_display.py file and paste the following code:

#!/usr/bin/env python3

import time

from luma.core.interface.serial import i2c
from luma.oled.device import ssd1306
from PIL import Image, ImageDraw, ImageFont

# 初始化 I2C OLED
serial = i2c(port=5, address=0x3C)
device = ssd1306(serial)
font = ImageFont.load_default()

while True:
    image = Image.new("1", (128, 64))
    draw = ImageDraw.Draw(image)

    draw.text((0, 0), "RDK X5", font=font, fill=255)
    draw.text((0, 18), "I2C OLED Demo", font=font, fill=255)
    draw.text((0, 36), time.strftime("%H:%M:%S"), font=font, fill=255)

    device.display(image)

    time.sleep(1)

Run the Sample​

Run the sample with the following command:

python3 i2c_display.py

After it starts, the screen shows text and the current time.