Scroll a mirrored script

main.py

@@ -0,0 +1,71 @@
+from machine import Pin, SoftI2C
+import framebuf
+import json
+import machine
+import network
+import ubinascii
+import utime
+
+import ssd1306
+
+
+last_update = 0
+
+i2c = SoftI2C(sda=Pin(14), scl=Pin(15))
+oled_width = const(128)
+oled_height = const(32)
+oled = ssd1306.SSD1306_I2C(oled_width, oled_height, i2c)
+buf = bytearray((oled_height // 8) * oled_width)
+fbuf = framebuf.FrameBuffer(buf, oled_width, oled_height, framebuf.MONO_VLSB)
+
+
+SCRIPT = """
+Hello!
+
+This is a sample
+script!
+This is even more
+text to show!
+"""
+
+
+def flipx(buf: bytearray, width: int, height: int) -> None:
+    view = memoryview(buf)
+    for y in range(height):
+        start = y * width
+        view[start : start + width] = bytearray(reversed(view[start : start + width]))
+
+
+def linebuffers(text):
+    buf = bytearray(oled_width)
+    fbuf = framebuf.FrameBuffer(
+        buf,
+        oled_width,
+        8,
+        framebuf.MONO_VLSB,
+    )
+    for line in text:
+        fbuf.fill(0)
+        fbuf.text(line, 0, 0)
+        flipx(buf, oled_width, 1)
+        yield fbuf
+
+
+def loop():
+    lines = SCRIPT.strip().splitlines()
+    # Pad out the ending with blank lines
+    lines += [""] * (oled_height // 8)
+    # Start out with a blank screen
+    oled.framebuf.fill(0)
+    oled.show()
+    for line in linebuffers(lines):
+        for i in range(8):
+            utime.sleep(0.1)
+            oled.framebuf.scroll(0, -1)
+            oled.framebuf.blit(line, 0, oled_height - i)
+            oled.show()
+    oled.framebuf.fill(0)
+    oled.show()
+
+
+loop()

ssd1306.py

@@ -0,0 +1,167 @@
+#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()