Show pageBacklinksExport to PDFBack to top This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong. ====== ESP8266 MicroPython Project with OLED ====== <wrap lo>Sunday January 12, 2025</wrap> In my [[posts:2025:2025_01_05_uv_esp8266|last post]], we walked through setup of an ESP8266 project managed with UV. Now we’ll construct a more complex project, adding a simple OLED display. ===== Hardware ===== Parts needed: * esp8266 board * OLED 0.96 inch Display * jumper wires * breadboard (All of this is included in the [[https://www.amazon.com/gp/product/B0BVZBTP8V|ESP32 Basic Starter Kit]]). Follow this schematic: {{:posts:2025:es8266-oled_bb-1.jpg|}} Connections: ^ OLED ^ ESP8266 ^ | VCC | 3.3V | | GND | GND | | SCL | GPIO 5 (D1) | | SDA | GPIO 4 (D2) | ===== Software ===== ==== Initialize Project ==== <code bash> mkdir esp8266_oled cd esp8266_oled uv init </code> ==== Add Dependencies ==== <code bash> uv add esptool uv add adafruit-ampy </code> Make sure you can communicate with the esp8266: <code bash> uv tool run --from esptool esptool.py chip_id </code> ==== Flash MicroPython to the ESP8266 ==== <WRAP prewrap> <code bash> wget https://micropython.org/resources/firmware/ESP8266_GENERIC-20241129-v1.24.1.bin uv tool run --from esptool esptool.py erase_flash uv tool run --from esptool esptool.py --baud 460800 write_flash --flash_size=detect 0 ESP8266_GENERIC-20241129-v1.24.1.bin </code> </WRAP> ==== Create Scripts ==== The MicroPython standard library doesn’t include support for the OLED by default. We’ll create a new **ssd1306.py** file and update it with the required code. <code bash> touch ssd1306.py </code> Copy the contents of https://github.com/RuiSantosdotme/ESP-MicroPython/raw/master/code/Others/OLED/ssd1306.py into the file: <WRAP prewrap> <code python> # 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) 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() </code> </WRAP> Create and update **main.py**. This is our entry point. <code bash> touch main.py </code> - Copy contents of https://github.com/RuiSantosdotme/ESP-MicroPython/raw/master/code/Others/OLED/main.py into the file, then - Comment the esp32 pin assignment and uncomment the esp8266 pin assignment Contents should end up like this: <code python> # Complete project details at https://RandomNerdTutorials.com/micropython-programming-with-esp32-and-esp8266/ from machine import Pin, SoftI2C import ssd1306 from time import sleep # ESP32 Pin assignment # i2c = SoftI2C(scl=Pin(22), sda=Pin(21)) # esp32 # ESP8266 Pin assignment i2c = SoftI2C(scl=Pin(5), sda=Pin(4)) oled_width = 128 oled_height = 64 oled = ssd1306.SSD1306_I2C(oled_width, oled_height, i2c) oled.text('Hello, World!', 0, 0) oled.text('Hello, World 2!', 0, 10) oled.text('Hello, World 3!', 0, 20) oled.show() </code> ==== Upload Scripts to ESP3266 ==== <code bash> uv tool run --from adafruit-ampy ampy -p /dev/ttyUSB0 put ssd1306.py uv tool run --from adafruit-ampy ampy -p /dev/ttyUSB0 put main.py uv tool run --from adafruit-ampy ampy -p /dev/ttyUSB0 ls </code> ==== Run the Main Script ==== <code bash> uv tool run --from adafruit-ampy ampy -p /dev/ttyUSB0 run main.py </code> On the OLED display you should see this: <code> Hello, World! Hello, World 2! Hello, World 3! </code> You can learn more about what the code is doing here: https://randomnerdtutorials.com/micropython-oled-display-esp32-esp8266/ posts/2025/2025_01_12_esp8266_oled.txt Last modified: 2025/03/30 10:54by jimc