quad color

adafruit_epd/jd79661.py

@@ -0,0 +1,610 @@
+# SPDX-FileCopyrightText: 2024
+#
+# SPDX-License-Identifier: MIT
+
+"""
+`adafruit_epd.jd79661` - Adafruit JD79661 - quad-color ePaper display driver
+====================================================================================
+CircuitPython driver for Adafruit JD79661 quad-color display breakouts
+* Author(s): [Your name here]
+
+**Hardware:**
+* JD79661 Quad-Color ePaper Display
+
+**Notes on Architecture:**
+This is the first quad-color display in the CircuitPython EPD library. Unlike tri-color
+displays that use separate buffers for black and red/yellow, the JD79661 uses a single
+buffer with 2 bits per pixel to represent 4 colors (black, white, yellow, red).
+
+This driver overrides the parent class's dual-buffer architecture to accommodate the
+quad-color packed pixel format. All drawing operations are reimplemented to work with
+the 2-bit color depth.
+"""
+
+import time
+
+import adafruit_framebuf
+from micropython import const
+
+from adafruit_epd.epd import Adafruit_EPD
+
+try:
+    """Needed for type annotations"""
+    import typing
+
+    from busio import SPI
+    from digitalio import DigitalInOut
+    from typing_extensions import Literal
+
+except ImportError:
+    pass
+
+__version__ = "0.0.0+auto.0"
+__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_EPD.git"
+
+# Command constants
+_JD79661_PANEL_SETTING = const(0x00)
+_JD79661_POWER_SETTING = const(0x01)
+_JD79661_POWER_OFF = const(0x02)
+_JD79661_POWER_ON = const(0x04)
+_JD79661_BOOSTER_SOFTSTART = const(0x06)
+_JD79661_DEEP_SLEEP = const(0x07)
+_JD79661_DATA_START_XMIT = const(0x10)
+_JD79661_DISPLAY_REFRESH = const(0x12)
+_JD79661_PLL_CONTROL = const(0x30)
+_JD79661_CDI = const(0x50)
+_JD79661_RESOLUTION = const(0x61)
+
+# Color constants for internal use (2-bit values)
+_JD79661_BLACK = const(0b00)
+_JD79661_WHITE = const(0b01)
+_JD79661_YELLOW = const(0b10)
+_JD79661_RED = const(0b11)
+
+# Other command constants from init sequence
+_JD79661_POFS = const(0x03)
+_JD79661_TCON = const(0x60)
+_JD79661_CMD_E7 = const(0xE7)
+_JD79661_CMD_E3 = const(0xE3)
+_JD79661_CMD_B4 = const(0xB4)
+_JD79661_CMD_B5 = const(0xB5)
+_JD79661_CMD_E9 = const(0xE9)
+_JD79661_CMD_4D = const(0x4D)
+
+
+class Adafruit_JD79661(Adafruit_EPD):
+    """driver class for Adafruit JD79661 quad-color ePaper display breakouts
+    
+    This driver implements a quad-color display with a single buffer using 2 bits
+    per pixel. This differs from the parent class architecture which assumes
+    separate buffers for black and color pixels in tri-color displays.
+    
+    **Color Architecture:**
+    - Uses a single buffer with 2 bits per pixel
+    - Supports 4 colors: BLACK (0b00), WHITE (0b01), YELLOW (0b10), RED (0b11)
+    - All drawing methods are overridden to handle the 2-bit packed pixel format
+    - The parent class's dual-buffer methods (_blackframebuf/_colorframebuf) are
+      set to the same buffer for compatibility but are not used directly
+    """
+
+    # Add color constants for convenience - these match parent class where applicable
+    BLACK = const(0)   # 0b00 in the display buffer
+    WHITE = const(1)   # 0b01 in the display buffer
+    YELLOW = const(2)  # 0b10 in the display buffer  
+    RED = const(3)     # 0b11 in the display buffer
+
+    def __init__(
+        self,
+        width: int,
+        height: int,
+        spi: SPI,
+        *,
+        cs_pin: DigitalInOut,
+        dc_pin: DigitalInOut,
+        sramcs_pin: DigitalInOut,
+        rst_pin: DigitalInOut,
+        busy_pin: DigitalInOut,
+    ) -> None:
+        """Initialize the quad-color display driver.
+        
+        Note: This driver uses a different buffer architecture than the parent class.
+        Instead of separate black and color buffers, it uses a single buffer with
+        2 bits per pixel to represent 4 colors.
+        """
+        super().__init__(width, height, spi, cs_pin, dc_pin, sramcs_pin, rst_pin, busy_pin)
+
+        # Adjust width to be divisible by 8 for proper byte alignment
+        stride = width
+        if stride % 8 != 0:
+            stride += 8 - stride % 8
+
+        # For quad-color display, we need 2 bits per pixel
+        # So buffer size is width * height / 4 bytes
+        self._buffer1_size = int(stride * height / 4)
+        self._buffer2_size = 0  # No second buffer for this display
+
+        if sramcs_pin:
+            self._buffer1 = self.sram.get_view(0)
+            # IMPORTANT: Both buffers point to the same memory for compatibility
+            # with parent class, but only _buffer1 is actually used
+            self._buffer2 = self._buffer1
+        else:
+            self._buffer1 = bytearray(self._buffer1_size)
+            # IMPORTANT: Both buffers point to the same memory for compatibility
+            # with parent class, but only _buffer1 is actually used
+            self._buffer2 = self._buffer1
+
+        # Create framebuffers for API compatibility with parent class
+        # NOTE: These framebuffers are not used for actual drawing operations
+        # since they don't support 2-bit color depth. All drawing is done
+        # through overridden methods that directly manipulate the buffer.
+        self._framebuf1 = adafruit_framebuf.FrameBuffer(
+            self._buffer1,
+            width,
+            height,
+            stride=stride,
+            buf_format=adafruit_framebuf.MHMSB,
+        )
+        self._framebuf2 = self._framebuf1  # Same framebuffer for compatibility
+        
+        # Set single byte transactions
+        self._single_byte_tx = True
+        
+        # Set up buffer references for parent class compatibility
+        # Both point to the same buffer since we don't have separate color planes
+        self.set_black_buffer(0, False)
+        self.set_color_buffer(0, False)
+        
+        # Initialize with default fill
+        self.fill(Adafruit_JD79661.WHITE)
+
+    def begin(self, reset: bool = True) -> None:
+        """Begin communication with the display and set basic settings"""
+        if reset:
+            self.hardware_reset()
+        time.sleep(0.1)
+        self.power_down()
+
+    def busy_wait(self) -> None:
+        """Wait for display to be done with current task, either by polling the
+        busy pin, or pausing. Note: JD79661 busy is HIGH when busy"""
+        if self._busy:
+            while not self._busy.value:  # Wait for busy HIGH
+                time.sleep(0.01)
+        else:
+            time.sleep(0.5)
+
+    def power_up(self) -> None:
+        """Power up the display in preparation for writing RAM and updating"""
+        self.hardware_reset()
+        self.busy_wait()
+        
+        # Send initialization sequence
+        time.sleep(0.01)  # Wait 10ms
+        
+        self.command(_JD79661_CMD_4D, bytearray([0x78]))
+        self.command(_JD79661_PANEL_SETTING, bytearray([0x8F, 0x29]))  # PSR, Display resolution is 128x250
+        self.command(_JD79661_POWER_SETTING, bytearray([0x07, 0x00]))  # PWR
+        self.command(_JD79661_POFS, bytearray([0x10, 0x54, 0x44]))  # POFS
+        self.command(_JD79661_BOOSTER_SOFTSTART, bytearray([0x05, 0x00, 0x3F, 0x0A, 0x25, 0x12, 0x1A]))
+        self.command(_JD79661_CDI, bytearray([0x37]))  # CDI
+        self.command(_JD79661_TCON, bytearray([0x02, 0x02]))  # TCON
+        self.command(_JD79661_RESOLUTION, bytearray([0, 128, 0, 250]))  # TRES
+        self.command(_JD79661_CMD_E7, bytearray([0x1C]))
+        self.command(_JD79661_CMD_E3, bytearray([0x22]))
+        self.command(_JD79661_CMD_B4, bytearray([0xD0]))
+        self.command(_JD79661_CMD_B5, bytearray([0x03]))
+        self.command(_JD79661_CMD_E9, bytearray([0x01]))
+        self.command(_JD79661_PLL_CONTROL, bytearray([0x08]))
+        self.command(_JD79661_POWER_ON)
+        
+        self.busy_wait()
+
+    def power_down(self) -> None:
+        """Power down the display - required when not actively displaying!"""
+        # Only deep sleep if we have a reset pin
+        if self._rst:
+            self.command(_JD79661_POWER_OFF, bytearray([0x00]))
+            self.busy_wait()
+            self.command(_JD79661_DEEP_SLEEP, bytearray([0xA5]))
+            time.sleep(0.1)
+
+    def update(self) -> None:
+        """Update the display from internal memory"""
+        self.command(_JD79661_DISPLAY_REFRESH, bytearray([0x00]))
+        self.busy_wait()
+        if not self._busy:
+            time.sleep(1)  # Wait 1 second if no busy pin
+
+    def write_ram(self, index: Literal[0, 1]) -> int:
+        """Send the one byte command for starting the RAM write process.
+        
+        Note: The index parameter is ignored since JD79661 uses a single buffer.
+        This parameter exists for API compatibility with the parent class.
+        """
+        # JD79661 uses same command for all data
+        return self.command(_JD79661_DATA_START_XMIT, end=False)
+
+    def set_ram_address(self, x: int, y: int) -> None:
+        """Set the RAM address location.
+        
+        Note: Not used on JD79661 chipset. Exists for API compatibility.
+        """
+        # Not used for JD79661
+        pass
+
+    def fill(self, color: int) -> None:
+        """Fill the entire display with the specified color.
+        
+        This method is overridden to handle the 2-bit packed pixel format
+        used by the quad-color display.
+        
+        Args:
+            color: Color value (BLACK, WHITE, YELLOW, or RED)
+        
+        Raises:
+            ValueError: If an invalid color is specified
+        """
+        # Map colors to fill patterns (4 pixels per byte)
+        color_map = {
+            Adafruit_JD79661.BLACK: 0x00,   # 0b00000000 - all pixels black
+            Adafruit_JD79661.WHITE: 0x55,   # 0b01010101 - all pixels white
+            Adafruit_JD79661.YELLOW: 0xAA,  # 0b10101010 - all pixels yellow
+            Adafruit_JD79661.RED: 0xFF,     # 0b11111111 - all pixels red
+        }
+        
+        if color not in color_map:
+            raise ValueError(f"Invalid color: {color}. Use BLACK (0), WHITE (1), YELLOW (2), or RED (3).")
+        
+        fill_byte = color_map[color]
+        
+        if self.sram:
+            self.sram.erase(0x00, self._buffer1_size, fill_byte)
+        else:
+            for i in range(self._buffer1_size):
+                self._buffer1[i] = fill_byte
+
+    def pixel(self, x: int, y: int, color: int) -> None:
+        """Draw a single pixel in the display buffer.
+        
+        This method is overridden to handle the 2-bit packed pixel format.
+        Each byte contains 4 pixels, with 2 bits per pixel.
+        
+        Args:
+            x: X coordinate
+            y: Y coordinate  
+            color: Color value (BLACK, WHITE, YELLOW, or RED)
+        """
+        if (x < 0) or (x >= self.width) or (y < 0) or (y >= self.height):
+            return
+
+        # Handle rotation
+        if self.rotation == 1:
+            x, y = y, x
+            x = self._width - x - 1
+            if self._width % 8 != 0:
+                x -= self._width % 8
+        elif self.rotation == 2:
+            x = self._width - x - 1
+            y = self._height - y - 1
+            if self._width % 8 != 0:
+                x += self._width % 8
+        elif self.rotation == 3:
+            x, y = y, x
+            y = self._height - y - 1
+
+        # Calculate stride (width adjusted to be divisible by 8)
+        stride = self._width
+        if stride % 8 != 0:
+            stride += 8 - stride % 8
+
+        # Map color constants to 2-bit values
+        color_map = {
+            Adafruit_JD79661.BLACK: _JD79661_BLACK,
+            Adafruit_JD79661.WHITE: _JD79661_WHITE,
+            Adafruit_JD79661.YELLOW: _JD79661_YELLOW,
+            Adafruit_JD79661.RED: _JD79661_RED,
+        }
+        
+        if color not in color_map:
+            # Default to white for invalid colors
+            pixel_color = _JD79661_WHITE
+        else:
+            pixel_color = color_map[color]
+
+        # Calculate byte address (4 pixels per byte)
+        addr = (x + y * stride) // 4
+        
+        # Calculate bit offset within byte (2 bits per pixel)
+        # Pixels are packed left-to-right, MSB first
+        bit_offset = (3 - (x % 4)) * 2
+        
+        # Create masks
+        byte_mask = 0x3 << bit_offset
+        byte_value = (pixel_color & 0x3) << bit_offset
+        
+        # Read, modify, write
+        if self.sram:
+            current = self.sram.read8(addr)
+            current &= ~byte_mask
+            current |= byte_value
+            self.sram.write8(addr, current)
+        else:
+            self._buffer1[addr] &= ~byte_mask
+            self._buffer1[addr] |= byte_value
+
+    # Override these methods to handle quad-color properly
+    def rect(self, x: int, y: int, width: int, height: int, color: int) -> None:
+        """Draw a rectangle.
+        
+        Overridden to use the quad-color pixel method.
+        """
+        for i in range(x, x + width):
+            self.pixel(i, y, color)
+            self.pixel(i, y + height - 1, color)
+        for j in range(y + 1, y + height - 1):
+            self.pixel(x, j, color)
+            self.pixel(x + width - 1, j, color)
+
+    def fill_rect(self, x: int, y: int, width: int, height: int, color: int) -> None:
+        """Fill a rectangle with the passed color.
+        
+        Overridden to use the quad-color pixel method.
+        """
+        for i in range(x, x + width):
+            for j in range(y, y + height):
+                self.pixel(i, j, color)
+
+    def line(self, x_0: int, y_0: int, x_1: int, y_1: int, color: int) -> None:
+        """Draw a line from (x_0, y_0) to (x_1, y_1) in passed color.
+        
+        Overridden to use the quad-color pixel method.
+        """
+        # Bresenham's line algorithm
+        dx = abs(x_1 - x_0)
+        dy = abs(y_1 - y_0)
+        sx = 1 if x_0 < x_1 else -1
+        sy = 1 if y_0 < y_1 else -1
+        err = dx - dy
+        
+        while True:
+            self.pixel(x_0, y_0, color)
+            if x_0 == x_1 and y_0 == y_1:
+                break
+            e2 = 2 * err
+            if e2 > -dy:
+                err -= dy
+                x_0 += sx
+            if e2 < dx:
+                err += dx
+                y_0 += sy
+
+    def text(
+        self,
+        string: str,
+        x: int,
+        y: int,
+        color: int,
+        *,
+        font_name: str = "font5x8.bin",
+        size: int = 1,
+    ) -> None:
+        """Write text string at location (x, y) in given color, using font file.
+        
+        This method is for CircuitPython's built-in bitmap fonts only.
+        For TrueType fonts, use PIL/Pillow to draw text on an image and then
+        display the image using the image() method.
+        """
+        # Validate color
+        if color not in [Adafruit_JD79661.BLACK, Adafruit_JD79661.WHITE, 
+                         Adafruit_JD79661.YELLOW, Adafruit_JD79661.RED]:
+            raise ValueError(f"Invalid color: {color}. Use BLACK (0), WHITE (1), YELLOW (2), or RED (3).")
+        
+        # Since we can't use the parent's framebuffer text method directly
+        # (it only supports 1-bit depth), we need to render to a temporary buffer
+        # and then copy the pixels in the requested color
+        
+        # Estimate text dimensions
+        text_width = len(string) * 6 * size  # ~6 pixels per char
+        text_height = 8 * size  # 8 pixel high font
+        
+        # Bounds check
+        text_width = min(text_width, self.width - x)
+        text_height = min(text_height, self.height - y)
+        
+        if text_width <= 0 or text_height <= 0:
+            return
+        
+        # Create temporary monochrome buffer
+        temp_buf_width = ((text_width + 7) // 8) * 8
+        temp_buf = bytearray((temp_buf_width * text_height) // 8)
+        
+        # Create temporary framebuffer
+        temp_fb = adafruit_framebuf.FrameBuffer(
+            temp_buf,
+            temp_buf_width,
+            text_height,
+            buf_format=adafruit_framebuf.MHMSB
+        )
+        
+        # Render text
+        temp_fb.fill(0)
+        temp_fb.text(string, 0, 0, 1, font_name=font_name, size=size)
+        
+        # Copy pixels in the requested color
+        for j in range(text_height):
+            for i in range(text_width):
+                byte_index = (j * temp_buf_width + i) // 8
+                bit_index = 7 - ((j * temp_buf_width + i) % 8)
+                
+                if byte_index < len(temp_buf):
+                    if (temp_buf[byte_index] >> bit_index) & 1:
+                        self.pixel(x + i, y + j, color)
+
+    def image(self, image: Image) -> None:
+        """Set buffer to value of Python Imaging Library image.  The image should
+        be in RGB mode and a size equal to the display size.
+        """
+        imwidth, imheight = image.size
+        if imwidth != self.width or imheight != self.height:
+            raise ValueError(
+                f"Image must be same dimensions as display ({self.width}x{self.height})."
+            )
+        if self.sram:
+            raise RuntimeError("PIL image is not for use with SRAM assist")
+        # Grab all the pixels from the image, faster than getpixel.
+        pix = image.load()
+        # clear out any display buffers
+        self.fill(Adafruit_EPD.WHITE)
+
+        if image.mode == "RGB":  # RGB Mode
+            for y in range(image.size[1]):
+                for x in range(image.size[0]):
+                    pixel = pix[x, y]
+                    # Check for yellow first (high red + green, low blue)
+                    if (pixel[0] >= 0x80) and (pixel[1] >= 0x80) and (pixel[2] < 0x80):
+                        # yellowish
+                        self.pixel(x, y, Adafruit_JD79661.YELLOW)
+                    # Then check for red (high red, low green and blue)
+                    elif (pixel[0] >= 0x80) and (pixel[1] < 0x80) and (pixel[2] < 0x80):
+                        # reddish
+                        self.pixel(x, y, Adafruit_JD79661.RED)
+                    # Then black (all low)
+                    elif (pixel[0] < 0x80) and (pixel[1] < 0x80) and (pixel[2] < 0x80):
+                        # dark
+                        self.pixel(x, y, Adafruit_JD79661.BLACK)
+                    # else: remains white (from fill)
+                    
+        elif image.mode == "L":  # Grayscale
+            for y in range(image.size[1]):
+                for x in range(image.size[0]):
+                    pixel = pix[x, y]
+                    if pixel < 0x40:  # 0-63
+                        self.pixel(x, y, Adafruit_JD79661.BLACK)
+                    elif pixel < 0x80:  # 64-127
+                        self.pixel(x, y, Adafruit_JD79661.YELLOW)
+                    elif pixel < 0xC0:  # 128-191
+                        self.pixel(x, y, Adafruit_JD79661.RED)
+                    # else: 192-255 remains white
+        else:
+            raise ValueError("Image must be in mode RGB or mode L.")
+
+    def image_dithered(self, image, dither_type="floyd-steinberg") -> None:
+        """Display an image with dithering to better represent colors/shades.
+        
+        This method converts the image to use only the 4 available colors
+        using error diffusion dithering for better visual quality.
+        
+        Args:
+            image: PIL Image object
+            dither_type: Type of dithering - "floyd-steinberg" or "simple"
+            
+        Raises:
+            ValueError: If image dimensions don't match display
+            RuntimeError: If SRAM is being used (not supported)
+        """
+        imwidth, imheight = image.size
+        if imwidth != self.width or imheight != self.height:
+            raise ValueError(
+                f"Image must be same dimensions as display ({self.width}x{self.height})."
+            )
+        if self.sram:
+            raise RuntimeError("PIL image dithering is not supported with SRAM assist")
+        
+        # Convert to RGB if not already
+        if image.mode != "RGB":
+            image = image.convert("RGB")
+        
+        # Define our 4 color palette in RGB
+        palette = [
+            (0, 0, 0),       # BLACK
+            (255, 255, 255), # WHITE
+            (255, 255, 0),   # YELLOW
+            (255, 0, 0),     # RED
+        ]
+        
+        # Create a working copy of the image as a list of lists
+        pixels = []
+        for y in range(imheight):
+            row = []
+            for x in range(imwidth):
+                r, g, b = image.getpixel((x, y))
+                row.append([r, g, b])
+            pixels.append(row)
+        
+        if dither_type == "floyd-steinberg":
+            # Floyd-Steinberg dithering
+            for y in range(imheight):
+                for x in range(imwidth):
+                    old_pixel = pixels[y][x]
+                    
+                    # Find closest color in palette
+                    min_dist = float('inf')
+                    closest_color = 0
+                    closest_rgb = palette[0]
+                    
+                    for i, pal_color in enumerate(palette):
+                        dist = sum((old_pixel[j] - pal_color[j])**2 for j in range(3))
+                        if dist < min_dist:
+                            min_dist = dist
+                            closest_color = i
+                            closest_rgb = pal_color
+                    
+                    # Set pixel to closest color
+                    self.pixel(x, y, closest_color)
+                    
+                    # Calculate error
+                    error = [old_pixel[i] - closest_rgb[i] for i in range(3)]
+                    
+                    # Distribute error to neighboring pixels
+                    if x + 1 < imwidth:
+                        for i in range(3):
+                            pixels[y][x + 1][i] += error[i] * 7 / 16
+                    
+                    if y + 1 < imheight:
+                        if x > 0:
+                            for i in range(3):
+                                pixels[y + 1][x - 1][i] += error[i] * 3 / 16
+                        
+                        for i in range(3):
+                            pixels[y + 1][x][i] += error[i] * 5 / 16
+                        
+                        if x + 1 < imwidth:
+                            for i in range(3):
+                                pixels[y + 1][x + 1][i] += error[i] * 1 / 16
+        
+        else:  # Simple nearest-color mapping
+            for y in range(imheight):
+                for x in range(imwidth):
+                    pixel = pixels[y][x]
+                    
+                    # Find closest color in palette
+                    min_dist = float('inf')
+                    closest_color = 0
+                    
+                    for i, pal_color in enumerate(palette):
+                        dist = sum((pixel[j] - pal_color[j])**2 for j in range(3))
+                        if dist < min_dist:
+                            min_dist = dist
+                            closest_color = i
+                    
+                    self.pixel(x, y, closest_color)
+
+    # Parent class drawing method overrides for documentation
+    def set_black_buffer(self, index: Literal[0, 1], inverted: bool) -> None:
+        """Set the index for the black buffer data.
+        
+        Note: This method exists for API compatibility but has no effect on the
+        JD79661 since it uses a single buffer with 2-bit color depth rather than
+        separate black/color buffers.
+        """
+        super().set_black_buffer(index, inverted)
+
+    def set_color_buffer(self, index: Literal[0, 1], inverted: bool) -> None:
+        """Set the index for the color buffer data.
+        
+        Note: This method exists for API compatibility but has no effect on the
+        JD79661 since it uses a single buffer with 2-bit color depth rather than
+        separate black/color buffers.
+        """
+        super().set_color_buffer(index, inverted)