For me, ‘oled.invert(1)’ gives me inverted text/background colors.
‘oled.invert(0)’ returns the display to normal (light text/dark background)

Jerry

MicroPython SSD1306 OLED driver, I2C and SPI interfaces

from micropython import const
import framebuf

register definitions

SET_CONTRAST = const(0x81)
SET_ENTIRE_ON = const(0xA4)
SET_NORM_INV = const(0xA6)
SET_DISP = const(0xAE)
SET_MEM_ADDR = const(0x20)
SET_COL_ADDR = const(0x21)
SET_PAGE_ADDR = const(0x22)
SET_DISP_START_LINE = const(0x40)
SET_SEG_REMAP = const(0xA0)
SET_MUX_RATIO = const(0xA8)
SET_COM_OUT_DIR = const(0xC0)
SET_DISP_OFFSET = const(0xD3)
SET_COM_PIN_CFG = const(0xDA)
SET_DISP_CLK_DIV = const(0xD5)
SET_PRECHARGE = const(0xD9)
SET_VCOM_DESEL = const(0xDB)
SET_CHARGE_PUMP = const(0x8D)

Subclassing FrameBuffer provides support for graphics primitives

http://docs.micropython.org/en/latest/pyboard/library/framebuf.html

class SSD1306(framebuf.FrameBuffer):
def init(self, width, height, external_vcc):
self.width = width
self.height = height
self.external_vcc = external_vcc
self.pages = self.height // 8
self.buffer = bytearray(self.pages * self.width)
super().init(self.buffer, self.width, self.height, framebuf.MONO_VLSB)
self.init_display()

def init_display(self):
for cmd in (
SET_DISP | 0x00, # off
# address setting
SET_MEM_ADDR,
0x00, # horizontal
# resolution and layout
SET_DISP_START_LINE | 0x00,
SET_SEG_REMAP | 0x01, # column addr 127 mapped to SEG0
SET_MUX_RATIO,
self.height - 1,
SET_COM_OUT_DIR | 0x08, # scan from COM[N] to COM0
SET_DISP_OFFSET,
0x00,
SET_COM_PIN_CFG,
0x02 if self.width > 2 * self.height else 0x12,
# timing and driving scheme
SET_DISP_CLK_DIV,
0x80,
SET_PRECHARGE,
0x22 if self.external_vcc else 0xF1,
SET_VCOM_DESEL,
0x30, # 0.83*Vcc
# display
SET_CONTRAST,
0xFF, # maximum
SET_ENTIRE_ON, # output follows RAM contents
SET_NORM_INV, # not inverted
# charge pump
SET_CHARGE_PUMP,
0x10 if self.external_vcc else 0x14,
SET_DISP | 0x01,
): # on
self.write_cmd(cmd)
self.fill(0)
self.show()

def show(self):
x0 = 0
x1 = self.width - 1
if self.width == 64:
# displays with width of 64 pixels are shifted by 32
x0 += 32
x1 += 32
self.write_cmd(SET_COL_ADDR)
self.write_cmd(x0)
self.write_cmd(x1)
self.write_cmd(SET_PAGE_ADDR)
self.write_cmd(0)
self.write_cmd(self.pages - 1)
self.write_data(self.buffer)


class SSD1306_I2C(SSD1306):
def init(self, width, height, i2c, addr=0x3C, external_vcc=False):
self.i2c = i2c
self.addr = addr
self.temp = bytearray(2)
self.write_list = [b”\x40″, None] # Co=0, D/C#=1
super().init(width, height, external_vcc)

def write_cmd(self, cmd):
self.temp[0] = 0x80 # Co=1, D/C#=0
self.temp[1] = cmd
self.i2c.writeto(self.addr, self.temp)

def write_data(self, buf):
self.write_list[1] = buf
self.i2c.writevto(self.addr, self.write_list)


class SSD1306_SPI(SSD1306):
def init(self, width, height, spi, dc, res, cs, external_vcc=False):
self.rate = 10 * 1024 * 1024
dc.init(dc.OUT, value=0)
res.init(res.OUT, value=0)
cs.init(cs.OUT, value=1)
self.spi = spi
self.dc = dc
self.res = res
self.cs = cs
import time

self.res(1)
time.sleep_ms(1)
self.res(0)
time.sleep_ms(10)
self.res(1)
super().__init__(width, height, external_vcc)

def write_data(self, buf):
self.spi.init(baudrate=self.rate, polarity=0, phase=0)
self.cs(1)
self.dc(1)
self.cs(0)
self.spi.write(buf)
self.cs(1)


program to load with Thonny:

Display Image & text on I2C driven ssd1306 OLED display

from machine import Pin, I2C
from ssd1306 import SSD1306_I2C
import framebuf

WIDTH = 128 # oled display width
HEIGHT = 64 # oled display height

i2c = I2C(0, scl=Pin(5), sda=Pin(4), freq=200000) # Init I2C using pins GP4& GP5 (default I2C0 pins)
print(“I2C Address : “+hex(i2c.scan()[0]).upper()) # Display device address
print(“I2C Configuration: “+str(i2c)) # Display I2C config

oled = SSD1306_I2C(WIDTH, HEIGHT, i2c) # Init oled display

Raspberry Pi logo as 32×32 bytearray

buffer = bytearray(b”\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00|?\x00\x01\x86@\x80\x01\x01\x80\x80\x01\x11\x88\x80\x01\x05\xa0\x80\x00\x83\xc1\x00\x00C\xe3\x00\x00~\xfc\x00\x00L’\x00\x00\x9c\x11\x00\x00\xbf\xfd\x00\x00\xe1\x87\x00\x01\xc1\x83\x80\x02A\x82@\x02A\x82@\x02\xc1\xc2@\x02\xf6>\xc0\x01\xfc=\x80\x01\x18\x18\x80\x01\x88\x10\x80\x00\x8c!\x00\x00\x87\xf1\x00\x00\x7f\xf6\x00\x008\x1c\x00\x00\x0c \x00\x00\x03\xc0\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00”)

Load the raspberry pi logo into the framebuffer (the image is 32×32)

fb = framebuf.FrameBuffer(buffer, 32, 32, framebuf.MONO_HLSB)

Clear the oled display in case it has junk on it.

oled.fill(0)

Blit the image from the framebuffer to the oled display

oled.blit(fb, 96, 0)

Add some text

oled.text(“Raspberry Pi”,5,5)
oled.text(“Pico”,5,15)

Finally update the oled display so the image & text is displayed

oled.show()

Hi.
Are you sure you have an SSD1306? Some OLED displays come with a different driver..
Regards,
Sara

My I2C scanner keeps reporting that its on 60 (0x3c), but this address doesn’t work, and returns the “OSError: [Errno 5] EIO”. I even set up a script to try to initialize the oled object with every hex address from 0 to 5000 (arbitrary number, I have no idea how many addresses are even capable of supporting the oled), but none worked. I’m combing through the ssd1306 module to see if something’s misconfigured in it now.

Hi.
I’ll add a note about that.
My display works well with 3.3V, but other models might require 5V.
Thanks for your contribution.
Regards,
Sara

Sara, I have an additional tip. I have been using a 128 X64 OLED display by Adafruit. After much frustration, I discovered that the only way to get consistent response is to use the 5 volt VBus on the pico. I have read about 25 tutorials, stackover threads, MicroPython threads and none of them mentioned that. I was receiving both errno 15, errno 8 and the no device error aa well as a wide range of errors messages referring to the ssd1306 library. 5 Volts fixed them all !!

Hi.
Check your I2C connections.
Additionally, double-check your OLED I2C address.
I’ve just added a section about it after realizing some people were having issues with it.
Regards,
Sara

Hi.
Please send me an email with your issue.
Make sure to be specific.
https://randomnerdtutorials.com/contact/
Regards,
Sara

Thanks for sharing the solution. I’ll add a note on the tutorial about finding the I2C address of the OLED.
Regards,
Sara

Hi.
I found two similar issues.
Take a look to see if any of the suggestions help:
forums.raspberrypi.com/viewtopic.php?t=343639
forums.raspberrypi.com/viewtopic.php?p=2046466&hilit=1306#p2046466

Regards,
Sara