ssd1306.py

   1 # MicroPython SSD1306 OLED driver, I2C and SPI interfaces
   2
   3 from micropython import const
   4 import framebuf
   5
   6
   7 # register definitions
   8 SET_CONTRAST = const(0x81)
   9 SET_ENTIRE_ON = const(0xA4)
  10 SET_NORM_INV = const(0xA6)
  11 SET_DISP = const(0xAE)
  12 SET_MEM_ADDR = const(0x20)
  13 SET_COL_ADDR = const(0x21)
  14 SET_PAGE_ADDR = const(0x22)
  15 SET_DISP_START_LINE = const(0x40)
  16 SET_SEG_REMAP = const(0xA0)
  17 SET_MUX_RATIO = const(0xA8)
  18 SET_COM_OUT_DIR = const(0xC0)
  19 SET_DISP_OFFSET = const(0xD3)
  20 SET_COM_PIN_CFG = const(0xDA)
  21 SET_DISP_CLK_DIV = const(0xD5)
  22 SET_PRECHARGE = const(0xD9)
  23 SET_VCOM_DESEL = const(0xDB)
  24 SET_CHARGE_PUMP = const(0x8D)
  25
  26 # Subclassing FrameBuffer provides support for graphics primitives
  27 # http://docs.micropython.org/en/latest/pyboard/library/framebuf.html
  28 class SSD1306(framebuf.FrameBuffer):
  29     def __init__(self, width, height, external_vcc):
  30         self.width = width
  31         self.height = height
  32         self.external_vcc = external_vcc
  33         self.pages = self.height // 8
  34         self.buffer = bytearray(self.pages * self.width)
  35         super().__init__(self.buffer, self.width, self.height, framebuf.MONO_VLSB)
  36         self.init_display()
  37
  38     def init_display(self):
  39         for cmd in (
  40             SET_DISP | 0x00,  # off
  41             # address setting
  42             SET_MEM_ADDR,
  43             0x00,  # horizontal
  44             # resolution and layout
  45             SET_DISP_START_LINE | 0x00,
  46             SET_SEG_REMAP | 0x01,  # column addr 127 mapped to SEG0
  47             SET_MUX_RATIO,
  48             self.height - 1,
  49             SET_COM_OUT_DIR | 0x08,  # scan from COM[N] to COM0
  50             SET_DISP_OFFSET,
  51             0x00,
  52             SET_COM_PIN_CFG,
  53             0x02 if self.width > 2 * self.height else 0x12,
  54             # timing and driving scheme
  55             SET_DISP_CLK_DIV,
  56             0x80,
  57             SET_PRECHARGE,
  58             0x22 if self.external_vcc else 0xF1,
  59             SET_VCOM_DESEL,
  60             0x30,  # 0.83*Vcc
  61             # display
  62             SET_CONTRAST,
  63             0xFF,  # maximum
  64             SET_ENTIRE_ON,  # output follows RAM contents
  65             SET_NORM_INV,  # not inverted
  66             # charge pump
  67             SET_CHARGE_PUMP,
  68             0x10 if self.external_vcc else 0x14,
  69             SET_DISP | 0x01,
  70         ):  # on
  71             self.write_cmd(cmd)
  72         self.fill(0)
  73         self.show()
  74
  75     def poweroff(self):
  76         self.write_cmd(SET_DISP | 0x00)
  77
  78     def poweron(self):
  79         self.write_cmd(SET_DISP | 0x01)
  80
  81     def contrast(self, contrast):
  82         self.write_cmd(SET_CONTRAST)
  83         self.write_cmd(contrast)
  84
  85     def invert(self, invert):
  86         self.write_cmd(SET_NORM_INV | (invert & 1))
  87
  88     def show(self):
  89         x0 = 0
  90         x1 = self.width - 1
  91         if self.width == 64:
  92             # displays with width of 64 pixels are shifted by 32
  93             x0 += 32
  94             x1 += 32
  95         self.write_cmd(SET_COL_ADDR)
  96         self.write_cmd(x0)
  97         self.write_cmd(x1)
  98         self.write_cmd(SET_PAGE_ADDR)
  99         self.write_cmd(0)
 100         self.write_cmd(self.pages - 1)
 101         self.write_data(self.buffer)
 102
 103
 104 class SSD1306_I2C(SSD1306):
 105     def __init__(self, width, height, i2c, addr=0x3C, external_vcc=False):
 106         self.i2c = i2c
 107         self.addr = addr
 108         self.temp = bytearray(2)
 109         self.write_list = [b"\x40", None]  # Co=0, D/C#=1
 110         super().__init__(width, height, external_vcc)
 111
 112     def write_cmd(self, cmd):
 113         self.temp[0] = 0x80  # Co=1, D/C#=0
 114         self.temp[1] = cmd
 115         self.i2c.writeto(self.addr, self.temp)
 116
 117     def write_data(self, buf):
 118         self.write_list[1] = buf
 119         self.i2c.writevto(self.addr, self.write_list)
 120
 121
 122 class SSD1306_SPI(SSD1306):
 123     def __init__(self, width, height, spi, dc, res, cs, external_vcc=False):
 124         self.rate = 10 * 1024 * 1024
 125         dc.init(dc.OUT, value=0)
 126         res.init(res.OUT, value=0)
 127         cs.init(cs.OUT, value=1)
 128         self.spi = spi
 129         self.dc = dc
 130         self.res = res
 131         self.cs = cs
 132         import time
 133
 134         self.res(1)
 135         time.sleep_ms(1)
 136         self.res(0)
 137         time.sleep_ms(10)
 138         self.res(1)
 139         super().__init__(width, height, external_vcc)
 140
 141     def write_cmd(self, cmd):
 142         self.spi.init(baudrate=self.rate, polarity=0, phase=0)
 143         self.cs(1)
 144         self.dc(0)
 145         self.cs(0)
 146         self.spi.write(bytearray([cmd]))
 147         self.cs(1)
 148
 149     def write_data(self, buf):
 150         self.spi.init(baudrate=self.rate, polarity=0, phase=0)
 151         self.cs(1)
 152         self.dc(1)
 153         self.cs(0)
 154         self.spi.write(buf)
 155         self.cs(1)