# MicroPython SSD1306 OLED driver, I2C and SPI interfaces

import framebuf


# register definitions
SET_CONTRAST = 0x81
SET_ENTIRE_ON = 0xa4
SET_NORM_INV = 0xa6
SET_DISP = 0xae
SET_MEM_ADDR = 0x20
SET_COL_ADDR = 0x21
SET_PAGE_ADDR = 0x22
SET_DISP_START_LINE = 0x40
SET_SEG_REMAP = 0xa0
SET_MUX_RATIO = 0xa8
SET_COM_OUT_DIR = 0xc0
SET_DISP_OFFSET = 0xd3
SET_COM_PIN_CFG = 0xda
SET_DISP_CLK_DIV = 0xd5
SET_PRECHARGE = 0xd9
SET_VCOM_DESEL = 0xdb
SET_CHARGE_PUMP = 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
        self.buffer = bytearray(self.pages * self.width)
        fb = framebuf.FrameBuffer(self.buffer, self.width, self.height, framebuf.MONO_VLSB)
        self.framebuf = fb
        # Provide methods for accessing FrameBuffer graphics primitives. This is a
        # workround because inheritance from a native class is currently unsupported.
        # http://docs.micropython.org/en/latest/pyboard/library/framebuf.html
        self.fill = fb.fill
        self.pixel = fb.pixel
        self.hline = fb.hline
        self.vline = fb.vline
        self.line = fb.line
        self.rect = fb.rect
        self.fill_rect = fb.fill_rect
        self.text = fb.text
        self.scroll = fb.scroll
        self.blit = fb.blit
        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 poweron(self):
        self.write_cmd(SET_DISP | 0x01)


    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_data(self.buffer)



class SSD1306_I2C(SSD1306):

    def __init__(self, width, height, i2c, addr = 0x3c, external_vcc = False):
        self.i2c = i2c
        self.addr = addr
        super().__init__(width, height, external_vcc)


    def write_cmd(self, cmd):
        self.i2c.writeto(self.addr, bytearray([0x80, cmd]))


    def write_data(self, buf):
        self.i2c.writeto(self.addr, bytearray([0x40]), False)
        self.i2c.write(buf)



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
        super().__init__(width, height, external_vcc)


    def write_cmd(self, cmd):
        # self.spi.init(baudrate = self.rate, polarity = 0, phase = 0)
        self.cs(1)
        self.dc(0)
        self.cs(0)
        self.spi.write(bytearray([cmd]))
        self.cs(1)


    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)


    def poweron(self):
        self.res(1)
        # time.sleep(0.001)
        # time.sleep_ms(1)
        self.res(0)
        # time.sleep(0.001)
        # time.sleep_ms(10)
        self.res(1)
