010 – ESP32 MicroPython: 0.96 OLED in MicroPython
In this tutorial, we will learn to use the 0.96 inch OLED display with monochrome display. This is useful for displaying something for the end user.
Its easy to use, we just need 4 wires. 2 wires for the power and another 2 wires for the i2c comunication protocol for controlling the display.
Circuit Diagram:
Instruction:
1. Connect the OLED VCC pin to 3V3 supply pin of ESP32.
2. Connect the OLED GND pin to ESP32 GND pin.
3. Connect the OLED SCL pin to ESP32 GPIO D22 pin (SCL dedicated pin).
4. Connect the OLED SDA pin to ESP32 GPIO D21 pin (SDA dedicated pin).
Video Demonstration:
I hope you find this tutorial as helpful. If you have any question regarding this tutorial, please do not hesitate to write it in the comment box provided.
Please also consider supporting me in my Youtube channel by Subscribing. Please click this to Subscribe and confirm.
Thank you and have a good days ahead.
Source Code:
SSD1306 Library:
Original copy of library (but with missing functions)
https://github.com/adafruit/micropython-adafruit-ssd1306/blob/master/ssd1306.py
#MicroPython SSD1306 OLED driver, I2C and SPI interfaces created by Adafruit
import time
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)
class SSD1306:
def __init__(self, width, height, external_vcc):
self.width = width
self.height = height
self.external_vcc = external_vcc
self.pages = self.height // 8
# Note the subclass must initialize self.framebuf to a framebuffer.
# This is necessary because the underlying data buffer is different
# between I2C and SPI implementations (I2C needs an extra byte).
self.poweron()
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.height == 32 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 poweroff(self):
self.write_cmd(SET_DISP | 0x00)
def contrast(self, contrast):
self.write_cmd(SET_CONTRAST)
self.write_cmd(contrast)
def invert(self, invert):
self.write_cmd(SET_NORM_INV | (invert & 1))
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_framebuf()
def fill(self, col):
self.framebuf.fill(col)
def pixel(self, x, y, col):
self.framebuf.pixel(x, y, col)
def scroll(self, dx, dy):
self.framebuf.scroll(dx, dy)
def text(self, string, x, y, col=1):
self.framebuf.text(string, x, y, col)
# Missing from current files in github:
# https://github.com/adafruit/micropython-adafruit-ssd1306/blob/master/ssd1306.py
def hline(self, x, y, w, col):
self.framebuf.hline(x, y, w, col)
def vline(self, x, y, h, col):
self.framebuf.vline(x, y, h, col)
def line(self, x1, y1, x2, y2, col):
self.framebuf.line(x1, y1, x2, y2, col)
def rect(self, x, y, w, h, col):
self.framebuf.rect(x, y, w, h, col)
def fill_rect(self, x, y, w, h, col):
self.framebuf.fill_rect(x, y, w, h, col)
def blit(self, fbuf, x, y):
self.framebuf.blit(fbuf, x, y)
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)
# Add an extra byte to the data buffer to hold an I2C data/command byte
# to use hardware-compatible I2C transactions. A memoryview of the
# buffer is used to mask this byte from the framebuffer operations
# (without a major memory hit as memoryview doesn't copy to a separate
# buffer).
self.buffer = bytearray(((height // 8) * width) + 1)
self.buffer[0] = 0x40 # Set first byte of data buffer to Co=0, D/C=1
self.framebuf = framebuf.FrameBuffer1(memoryview(self.buffer)[1:], width, height)
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_framebuf(self):
# Blast out the frame buffer using a single I2C transaction to support
# hardware I2C interfaces.
self.i2c.writeto(self.addr, self.buffer)
def poweron(self):
pass
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
self.buffer = bytearray((height // 8) * width)
self.framebuf = framebuf.FrameBuffer1(self.buffer, width, height)
super().__init__(width, height, external_vcc)
def write_cmd(self, cmd):
self.spi.init(baudrate=self.rate, polarity=0, phase=0)
self.cs.high()
self.dc.low()
self.cs.low()
self.spi.write(bytearray([cmd]))
self.cs.high()
def write_framebuf(self):
self.spi.init(baudrate=self.rate, polarity=0, phase=0)
self.cs.high()
self.dc.high()
self.cs.low()
self.spi.write(self.buffer)
self.cs.high()
def poweron(self):
self.res.high()
time.sleep_ms(1)
self.res.low()
time.sleep_ms(10)
self.res.high()
Example 1, Simple OLED demo:
# Simple demonstration of 0.96 OLED in MicroPython
# Author: George Bantique, TechToTinker
# Date: September 30, 2020
import ssd1306
import machine
scl = machine.Pin(22, machine.Pin.OUT, machine.Pin.PULL_UP)
sda = machine.Pin(21, machine.Pin.OUT, machine.Pin.PULL_UP)
i2c = machine.I2C(scl=scl, sda=sda, freq=400000)
oled = ssd1306.SSD1306_I2C(128, 64, i2c, addr=0x3C)
def print_text(msg, x, y, clr):
if clr:
oled.fill(0)
oled.text(msg, x, y)
oled.show()
print_text('Hello', 10, 10, 0)
print_text('Welcome', 20, 20, 0)
print_text('TechToTinker', 20, 20, 1)