reudsh3/ssd1306.py

# MicroPython SSD1306 OLED driver, I2C and SPI interfaces created by Adafruit

import time
import framebuf

from machine import Pin, SPI

# 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:
  framebuf: framebuf.FrameBuffer
  font: dict

  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)

  def blit(self, fbuf, x, y, key=-1, palette=None):
    self.framebuf.blit(fbuf, x, y, key, palette)

  def set_font(self, font):
    self.font = font

  def font_text(self, string, x_axis, y_axis):
    idx = 0
    for k in string:
      buf = self.font[k]
      self.framebuf.blit(buf, x_axis + idx * 16, y_axis)
      idx += 1


class SSD1306_SPI(SSD1306):
  def __init__(self, width, height, spi: SPI, dc: Pin, res: Pin, cs: Pin, 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.on()
    self.dc.off()
    self.cs.off()
    self.spi.write(bytearray([cmd]))
    self.cs.on()

  def write_framebuf(self):
    self.spi.init(baudrate=self.rate, polarity=0, phase=0)
    self.cs.on()
    self.dc.on()
    self.cs.off()
    self.spi.write(self.buffer)
    self.cs.on()

  def poweron(self):
    self.res.on()
    time.sleep_ms(1)
    self.res.off()
    time.sleep_ms(10)
    self.res.on()

def init_spi(width, height, spi, dc, res, cs, external_vcc=False) -> SSD1306_SPI:
  return SSD1306_SPI(width, height, spi, dc, res, cs, external_vcc)