oled_i2c.py
The 128x64 SSD1306 OLED wires to the I2C bus (GPIO2/GPIO3, pins 3 and 5) and boots with a command sequence. The script brings the bus up, clears the framebuffer, then hands over. On the model-5, enable I2C in raspi-config or config.txt first.
Hardware
A Raspberry Pi 5 (quad-core BCM2712 at 2.4 GHz, RP1 I/O chip, 40-pin GPIO, recommended 5 V/5 A USB-C power, two CSI camera ports). One 4-pin SSD1306 I2C OLED module, dupont wires.
Wiring
VCC to 3.3 V, GND to GND, SDA to GPIO2 (pin 3), SCL to GPIO3 (pin 5). The J8 40-pin header groups these pins at the corner.
How it works
smbus writes control byte 0x00 (command) or 0x40 (data) then payload bytes to address 0x3C; the sequence sets pump charge, contrast and scan.
Running it
Copy the script to the board (scp), then run it with python3. On Bookworm, gpiozero 2.x drives the pins through the RP1 chip; keep gpiozero and python3-rpi.gpio updated (sudo apt full-upgrade). A 5 V/5 A supply is advised.
Variants
Use luma.oled for text and fonts; two displays via a TCA9548A multiplexer. A 27 W (5 V/5 A) supply is recommended; without it USB output is capped at 600 mA total.
oled_i2c.py
# oled_i2c.py — affiche texte et courbe sur OLED SSD1306 en I2C.
# Deps: sudo apt install python3-smbus i2c-tools (activer i2c_arm)
import time
import smbus
ADDR = 0x3C
bus = smbus.SMBus(1)
def cmd(c):
bus.write_byte_data(ADDR, 0x00, c)
def data(buf):
bus.write_i2c_block_data(ADDR, 0x40, buf)
for c in [0xAE, 0xD5, 0x80, 0xA8, 0x3F, 0xD3, 0x00, 0x40, 0x8D, 0x14,
0xA1, 0xC8, 0xDA, 0x12, 0x81, 0xFF, 0xD9, 0xF1, 0xDB, 0x40,
0xA4, 0xA6, 0xAF]:
cmd(c)
data([0xF0] * 1024) # efface le framebuffer 128x64
print("OLED initialise, i2cdetect -y 1 pour verifier")