ssd1351.py

"""SSD1351 OLED module."""
from time import sleep
from math import cos, sin, pi, radians
from sys import implementation


def color565(r, g, b):
    """Return RGB565 color value.

    Args:
        r (int): Red value.
        g (int): Green value.
        b (int): Blue value.
    """
    return (r & 0xf8) << 8 | (g & 0xfc) << 3 | b >> 3


class Display(object):
    """Serial interface for 16-bit color (5-6-5 RGB) SSD1351 OLED display.

    Note:  All coordinates are zero based.
    """

    # Command constants from SSD1351 datasheet
    SET_COLUMN = const(0x15)
    SET_ROW = const(0x75)
    WRITE_RAM = const(0x5C)
    READ_RAM = const(0x5D)
    SET_REMAP = const(0xA0)
    START_LINE = const(0xA1)
    DISPLAY_OFFSET = const(0xA2)
    DISPLAY_ALL_OFF = const(0xA4)
    DISPLAY_ALL_ON = const(0xA5)
    NORMAL_DISPLAY = const(0xA6)
    INVERT_DISPLAY = const(0xA7)
    FUNCTION_SELECT = const(0xAB)
    DISPLAY_OFF = const(0xAE)
    DISPLAY_ON = const(0xAF)
    PRECHARGE = const(0xB1)
    DISPLAY_ENHANCEMENT = const(0xB2)
    CLOCK_DIV = const(0xB3)
    SET_VSL = const(0xB4)
    SET_GPIO = const(0xB5)
    PRECHARGE2 = const(0xB6)
    SET_GRAY = const(0xB8)
    USE_LUT = const(0xB9)
    PRECHARGE_LEVEL = const(0xBB)
    VCOMH = const(0xBE)
    CONTRAST_ABC = const(0xC1)
    CONTRAST_MASTER = const(0xC7)
    MUX_RATIO = const(0xCA)
    COMMAND_LOCK = const(0xFD)
    HORIZ_SCROLL = const(0x96)
    STOP_SCROLL = const(0x9E)
    START_SCROLL = const(0x9F)

    def __init__(self, spi, cs, dc, rst, width=128, height=128):
        """Initialize OLED.

        Args:
            spi (Class Spi):  SPI interface for OLED
            cs (Class Pin):  Chip select pin
            dc (Class Pin):  Data/Command pin
            rst (Class Pin):  Reset pin
            width (Optional int): Screen width (default 128)
            height (Optional int): Screen height (default 128)
        """
        self.spi = spi
        self.cs = cs
        self.dc = dc
        self.rst = rst
        self.width = width
        self.height = height
        # Initialize GPIO pins and set implementation specific methods
        if implementation.name == 'circuitpython':
            self.cs.switch_to_output(value=True)
            self.dc.switch_to_output(value=False)
            self.rst.switch_to_output(value=True)
            self.reset = self.reset_cpy
            self.write_cmd = self.write_cmd_cpy
            self.write_data = self.write_data_cpy
        else:
            self.cs.init(self.cs.OUT, value=1)
            self.dc.init(self.dc.OUT, value=0)
            self.rst.init(self.rst.OUT, value=1)
            self.reset = self.reset_mpy
            self.write_cmd = self.write_cmd_mpy
            self.write_data = self.write_data_mpy
        self.reset()
        # Send initialization commands
        self.write_cmd(self.COMMAND_LOCK, 0x12)  # Unlock IC MCU interface
        self.write_cmd(self.COMMAND_LOCK, 0xB1)  # A2,B1,B3,BB,BE,C1
        self.write_cmd(self.DISPLAY_OFF)  # Display off
        self.write_cmd(self.DISPLAY_ENHANCEMENT, 0xA4, 0x00, 0x00)
        self.write_cmd(self.CLOCK_DIV, 0xF0)  # Clock divider F1 or F0
        self.write_cmd(self.MUX_RATIO, 0x7F)  # Mux ratio
        self.write_cmd(self.SET_REMAP, 0x74)  # Segment remapping
        self.write_cmd(self.START_LINE, 0x00)  # Set Display start line
        self.write_cmd(self.DISPLAY_OFFSET, 0x00)  # Set display offset
        self.write_cmd(self.SET_GPIO, 0x00)  # Set GPIO
        self.write_cmd(self.FUNCTION_SELECT, 0x01)  # Function select
        self.write_cmd(self.PRECHARGE, 0x32),  # Precharge
        self.write_cmd(self.PRECHARGE_LEVEL, 0x1F)  # Precharge level
        self.write_cmd(self.VCOMH, 0x05)  # Set VcomH voltage
        self.write_cmd(self.NORMAL_DISPLAY)  # Normal Display
        self.write_cmd(self.CONTRAST_MASTER, 0x0A)  # Contrast master
        self.write_cmd(self.CONTRAST_ABC, 0xFF, 0xFF, 0xFF)  # Contrast RGB
        self.write_cmd(self.SET_VSL, 0xA0, 0xB5, 0x55)  # Set segment low volt.
        self.write_cmd(self.PRECHARGE2, 0x01)  # Precharge2
        self.write_cmd(self.DISPLAY_ON)  # Display on
        self.clear()

    def block(self, x0, y0, x1, y1, data):
        """Write a block of data to display.

        Args:
            x0 (int):  Starting X position.
            y0 (int):  Starting Y position.
            x1 (int):  Ending X position.
            y1 (int):  Ending Y position.
            data (bytes): Data buffer to write.
        """
        self.write_cmd(self.SET_COLUMN, x0, x1)
        self.write_cmd(self.SET_ROW, y0, y1)
        self.write_cmd(self.WRITE_RAM)
        self.write_data(data)

    def cleanup(self):
        """Clean up resources."""
        self.clear()
        self.display_off()
        self.spi.deinit()
        print('display off')

    def clear(self, color=0):
        """Clear display.

        Args:
            color (Optional int): RGB565 color value (Default: 0 = Black).
        """
        w = self.width
        h = self.height
        # Clear display in 1024 byte blocks
        if color:
            line = color.to_bytes(2, 'big') * 1024
        else:
            line = bytearray(2048)
        for x in range(0, w, 8):
            self.block(x, 0, x + 7, h - 1, line)

    def contrast(self, level):
        """Set display contrast to specified level.

        Args:
            level (int): Contrast level (0 - 15).
        Note:
            Can pass list to specifiy
        """
        assert(0 <= level < 16)
        self.write_cmd(self.CONTRAST_MASTER, level)

    def display_off(self):
        """Turn display off."""
        self.write_cmd(self.DISPLAY_OFF)

    def display_on(self):
        """Turn display on."""
        self.write_cmd(self.DISPLAY_ON)

    def draw_circle(self, x0, y0, r, color):
        """Draw a circle.

        Args:
            x0 (int): X coordinate of center point.
            y0 (int): Y coordinate of center point.
            r (int): Radius.
            color (int): RGB565 color value.
        """
        f = 1 - r
        dx = 1
        dy = -r - r
        x = 0
        y = r
        self.draw_pixel(x0, y0 + r, color)
        self.draw_pixel(x0, y0 - r, color)
        self.draw_pixel(x0 + r, y0, color)
        self.draw_pixel(x0 - r, y0, color)
        while x < y:
            if f >= 0:
                y -= 1
                dy += 2
                f += dy
            x += 1
            dx += 2
            f += dx
            self.draw_pixel(x0 + x, y0 + y, color)
            self.draw_pixel(x0 - x, y0 + y, color)
            self.draw_pixel(x0 + x, y0 - y, color)
            self.draw_pixel(x0 - x, y0 - y, color)
            self.draw_pixel(x0 + y, y0 + x, color)
            self.draw_pixel(x0 - y, y0 + x, color)
            self.draw_pixel(x0 + y, y0 - x, color)
            self.draw_pixel(x0 - y, y0 - x, color)

    def draw_ellipse(self, x0, y0, a, b, color):
        """Draw an ellipse.

        Args:
            x0, y0 (int): Coordinates of center point.
            a (int): Semi axis horizontal.
            b (int): Semi axis vertical.
            color (int): RGB565 color value.
        Note:
            The center point is the center of the x0,y0 pixel.
            Since pixels are not divisible, the axes are integer rounded
            up to complete on a full pixel.  Therefore the major and
            minor axes are increased by 1.
        """
        a2 = a * a
        b2 = b * b
        twoa2 = a2 + a2
        twob2 = b2 + b2
        x = 0
        y = b
        px = 0
        py = twoa2 * y
        # Plot initial points
        self.draw_pixel(x0 + x, y0 + y, color)
        self.draw_pixel(x0 - x, y0 + y, color)
        self.draw_pixel(x0 + x, y0 - y, color)
        self.draw_pixel(x0 - x, y0 - y, color)
        # Region 1
        p = round(b2 - (a2 * b) + (0.25 * a2))
        while px < py:
            x += 1
            px += twob2
            if p < 0:
                p += b2 + px
            else:
                y -= 1
                py -= twoa2
                p += b2 + px - py
            self.draw_pixel(x0 + x, y0 + y, color)
            self.draw_pixel(x0 - x, y0 + y, color)
            self.draw_pixel(x0 + x, y0 - y, color)
            self.draw_pixel(x0 - x, y0 - y, color)
        # Region 2
        p = round(b2 * (x + 0.5) * (x + 0.5) +
                  a2 * (y - 1) * (y - 1) - a2 * b2)
        while y > 0:
            y -= 1
            py -= twoa2
            if p > 0:
                p += a2 - py
            else:
                x += 1
                px += twob2
                p += a2 - py + px
            self.draw_pixel(x0 + x, y0 + y, color)
            self.draw_pixel(x0 - x, y0 + y, color)
            self.draw_pixel(x0 + x, y0 - y, color)
            self.draw_pixel(x0 - x, y0 - y, color)

    def draw_hline(self, x, y, w, color):
        """Draw a horizontal line.

        Args:
            x (int): Starting X position.
            y (int): Starting Y position.
            w (int): Width of line.
            color (int): RGB565 color value.
        """
        if self.is_off_grid(x, y, x + w - 1, y):
            return
        line = color.to_bytes(2, 'big') * w
        self.block(x, y, x + w - 1, y, line)

    def draw_image(self, path, x=0, y=0, w=128, h=128):
        """Draw image from flash.

        Args:
            path (string): Image file path.
            x (int): X coordinate of image left.  Default is 0.
            y (int): Y coordinate of image top.  Default is 0.
            w (int): Width of image.  Default is 128.
            h (int): Height of image.  Default is 128.
        """
        x2 = x + w - 1
        y2 = y + h - 1
        if self.is_off_grid(x, y, x2, y2):
            return
        with open(path, "rb") as f:
            chunk_height = 1024 // w
            chunk_count, remainder = divmod(h, chunk_height)
            chunk_size = chunk_height * w * 2
            chunk_y = y
            if chunk_count:
                for c in range(0, chunk_count):
                    buf = f.read(chunk_size)
                    self.block(x, chunk_y,
                               x2, chunk_y + chunk_height - 1,
                               buf)
                    chunk_y += chunk_height
            if remainder:
                buf = f.read(remainder * w * 2)
                self.block(x, chunk_y,
                           x2, chunk_y + remainder - 1,
                           buf)

    def draw_letter(self, x, y, letter, font, color, background=0,
                    landscape=False):
        """Draw a letter.

        Args:
            x (int): Starting X position.
            y (int): Starting Y position.
            letter (string): Letter to draw.
            font (XglcdFont object): Font.
            color (int): RGB565 color value.
            background (int): RGB565 background color (default: black).
            landscape (bool): Orientation (default: False = portrait)
        """
        buf, w, h = font.get_letter(letter, color, background,
                                    landscape)
        # Check for errors
        if w == 0:
            return w, h

        if landscape:
            y -= w
            if self.is_off_grid(x, y, x + h - 1, y + w - 1):
                return
            self.block(x, y,
                       x + h - 1, y + w - 1,
                       buf)
        else:
            if self.is_off_grid(x, y, x + w - 1, y + h - 1):
                return
            self.write_cmd(self.SET_REMAP, 0x75)  # Vertical address increment
            self.block(x, y,
                       x + w - 1, y + h - 1,
                       buf)
            self.write_cmd(self.SET_REMAP, 0x74)  # Switch back to horizontal
        return w, h

    def draw_line(self, x1, y1, x2, y2, color):
        """Draw a line using Bresenham's algorithm.

        Args:
            x1, y1 (int): Starting coordinates of the line
            x2, y2 (int): Ending coordinates of the line
            color (int): RGB565 color value.
        """
        # Check for horizontal line
        if y1 == y2:
            if x1 > x2:
                x1, x2 = x2, x1
            self.draw_hline(x1, y1, x2 - x1 + 1, color)
            return
        # Check for vertical line
        if x1 == x2:
            if y1 > y2:
                y1, y2 = y2, y1
            self.draw_vline(x1, y1, y2 - y1 + 1, color)
            return
        # Confirm coordinates in boundary
        if self.is_off_grid(min(x1, x2), min(y1, y2),
                            max(x1, x2), max(y1, y2)):
            return
        # Changes in x, y
        dx = x2 - x1
        dy = y2 - y1
        # Determine how steep the line is
        is_steep = abs(dy) > abs(dx)
        # Rotate line
        if is_steep:
            x1, y1 = y1, x1
            x2, y2 = y2, x2
        # Swap start and end points if necessary
        if x1 > x2:
            x1, x2 = x2, x1
            y1, y2 = y2, y1
        # Recalculate differentials
        dx = x2 - x1
        dy = y2 - y1
        # Calculate error
        error = dx >> 1
        ystep = 1 if y1 < y2 else -1
        y = y1
        for x in range(x1, x2 + 1):
            # Had to reverse HW ????
            if not is_steep:
                self.draw_pixel(x, y, color)
            else:
                self.draw_pixel(y, x, color)
            error -= abs(dy)
            if error < 0:
                y += ystep
                error += dx

    def draw_lines(self, coords, color):
        """Draw multiple lines.

        Args:
            coords ([[int, int],...]): Line coordinate X, Y pairs
            color (int): RGB565 color value.
        """
        # Starting point
        x1, y1 = coords[0]
        # Iterate through coordinates
        for i in range(1, len(coords)):
            x2, y2 = coords[i]
            self.draw_line(x1, y1, x2, y2, color)
            x1, y1 = x2, y2

    def draw_pixel(self, x, y, color):
        """Draw a single pixel.

        Args:
            x (int): X position.
            y (int): Y position.
            color (int): RGB565 color value.
        """
        if self.is_off_grid(x, y, x, y):
            return
        self.block(x, y, x, y, color.to_bytes(2, 'big'))

    def draw_polygon(self, sides, x0, y0, r, color, rotate=0):
        """Draw an n-sided regular polygon.

        Args:
            sides (int): Number of polygon sides.
            x0, y0 (int): Coordinates of center point.
            r (int): Radius.
            color (int): RGB565 color value.
            rotate (Optional float): Rotation in degrees relative to origin.
        Note:
            The center point is the center of the x0,y0 pixel.
            Since pixels are not divisible, the radius is integer rounded
            up to complete on a full pixel.  Therefore diameter = 2 x r + 1.
        """
        coords = []
        theta = radians(rotate)
        n = sides + 1
        for s in range(n):
            t = 2.0 * pi * s / sides + theta
            coords.append([int(r * cos(t) + x0), int(r * sin(t) + y0)])

        # Cast to python float first to fix rounding errors
        self.draw_lines(coords, color=color)

    def draw_rectangle(self, x, y, w, h, color):
        """Draw a rectangle.

        Args:
            x (int): Starting X position.
            y (int): Starting Y position.
            w (int): Width of rectangle.
            h (int): Height of rectangle.
            color (int): RGB565 color value.
        """
        x2 = x + w - 1
        y2 = y + h - 1
        self.draw_hline(x, y, w, color)
        self.draw_hline(x, y2, w, color)
        self.draw_vline(x, y, h, color)
        self.draw_vline(x2, y, h, color)

    def draw_sprite(self, buf, x, y, w, h):
        """Draw a sprite (optimized for horizontal drawing).

        Args:
            buf (bytearray): Buffer to draw.
            x (int): Starting X position.
            y (int): Starting Y position.
            w (int): Width of drawing.
            h (int): Height of drawing.
        """
        x2 = x + w - 1
        y2 = y + h - 1
        if self.is_off_grid(x, y, x2, y2):
            return
        self.block(x, y, x2, y2, buf)

    def draw_text(self, x, y, text, font, color,  background=0,
                  landscape=False, spacing=1):
        """Draw text.

        Args:
            x (int): Starting X position.
            y (int): Starting Y position.
            text (string): Text to draw.
            font (XglcdFont object): Font.
            color (int): RGB565 color value.
            background (int): RGB565 background color (default: black).
            landscape (bool): Orientation (default: False = portrait)
            spacing (int): Pixels between letters (default: 1)
        """
        for letter in text:
            # Get letter array and letter dimensions
            w, h = self.draw_letter(x, y, letter, font, color, background,
                                    landscape)
            # Stop on error
            if w == 0 or h == 0:
                print('Invalid width {0} or height {1}'.format(w, h))
                return

            if landscape:
                # Fill in spacing
                if spacing:
                    self.fill_hrect(x, y - w - spacing, h, spacing, background)
                # Position y for next letter
                y -= (w + spacing)
            else:
                # Fill in spacing
                if spacing:
                    self.fill_vrect(x + w, y, spacing, h, background)
                # Position x for next letter
                x += w + spacing

    def draw_vline(self, x, y, h, color):
        """Draw a vertical line.

        Args:
            x (int): Starting X position.
            y (int): Starting Y position.
            h (int): Height of line.
            color (int): RGB565 color value.
        """
        # Confirm coordinates in boundary
        if self.is_off_grid(x, y, x, y + h):
            return
        line = color.to_bytes(2, 'big') * h
        self.block(x, y, x, y + h - 1, line)

    def fill_circle(self, x0, y0, r, color):
        """Draw a filled circle.

        Args:
            x0 (int): X coordinate of center point.
            y0 (int): Y coordinate of center point.
            r (int): Radius.
            color (int): RGB565 color value.
        """
        f = 1 - r
        dx = 1
        dy = -r - r
        x = 0
        y = r
        self.draw_vline(x0, y0 - r, 2 * r + 1, color)
        while x < y:
            if f >= 0:
                y -= 1
                dy += 2
                f += dy
            x += 1
            dx += 2
            f += dx
            self.draw_vline(x0 + x, y0 - y, 2 * y + 1, color)
            self.draw_vline(x0 - x, y0 - y, 2 * y + 1, color)
            self.draw_vline(x0 - y, y0 - x, 2 * x + 1, color)
            self.draw_vline(x0 + y, y0 - x, 2 * x + 1, color)

    def fill_ellipse(self, x0, y0, a, b, color):
        """Draw a filled ellipse.

        Args:
            x0, y0 (int): Coordinates of center point.
            a (int): Semi axis horizontal.
            b (int): Semi axis vertical.
            color (int): RGB565 color value.
        Note:
            The center point is the center of the x0,y0 pixel.
            Since pixels are not divisible, the axes are integer rounded
            up to complete on a full pixel.  Therefore the major and
            minor axes are increased by 1.
        """
        a2 = a * a
        b2 = b * b
        twoa2 = a2 + a2
        twob2 = b2 + b2
        x = 0
        y = b
        px = 0
        py = twoa2 * y
        # Plot initial points
        self.draw_line(x0, y0 - y, x0, y0 + y, color)
        # Region 1
        p = round(b2 - (a2 * b) + (0.25 * a2))
        while px < py:
            x += 1
            px += twob2
            if p < 0:
                p += b2 + px
            else:
                y -= 1
                py -= twoa2
                p += b2 + px - py
            self.draw_line(x0 + x, y0 - y, x0 + x, y0 + y, color)
            self.draw_line(x0 - x, y0 - y, x0 - x, y0 + y, color)
        # Region 2
        p = round(b2 * (x + 0.5) * (x + 0.5) +
                  a2 * (y - 1) * (y - 1) - a2 * b2)
        while y > 0:
            y -= 1
            py -= twoa2
            if p > 0:
                p += a2 - py
            else:
                x += 1
                px += twob2
                p += a2 - py + px
            self.draw_line(x0 + x, y0 - y, x0 + x, y0 + y, color)
            self.draw_line(x0 - x, y0 - y, x0 - x, y0 + y, color)

    def fill_hrect(self, x, y, w, h, color):
        """Draw a filled rectangle (optimized for horizontal drawing).

        Args:
            x (int): Starting X position.
            y (int): Starting Y position.
            w (int): Width of rectangle.
            h (int): Height of rectangle.
            color (int): RGB565 color value.
        """
        if self.is_off_grid(x, y, x + w - 1, y + h - 1):
            return
        chunk_height = 1024 // w
        chunk_count, remainder = divmod(h, chunk_height)
        chunk_size = chunk_height * w
        chunk_y = y
        if chunk_count:
            buf = color.to_bytes(2, 'big') * chunk_size
            for c in range(0, chunk_count):
                self.block(x, chunk_y,
                           x + w - 1, chunk_y + chunk_height - 1,
                           buf)
                chunk_y += chunk_height

        if remainder:
            buf = color.to_bytes(2, 'big') * remainder * w
            self.block(x, chunk_y,
                       x + w - 1, chunk_y + remainder - 1,
                       buf)

    def fill_rectangle(self, x, y, w, h, color):
        """Draw a filled rectangle.

        Args:
            x (int): Starting X position.
            y (int): Starting Y position.
            w (int): Width of rectangle.
            h (int): Height of rectangle.
            color (int): RGB565 color value.
        """
        if self.is_off_grid(x, y, x + w - 1, y + h - 1):
            return
        if w > h:
            self.fill_hrect(x, y, w, h, color)
        else:
            self.fill_vrect(x, y, w, h, color)

    def fill_polygon(self, sides, x0, y0, r, color, rotate=0):
        """Draw a filled n-sided regular polygon.

        Args:
            sides (int): Number of polygon sides.
            x0, y0 (int): Coordinates of center point.
            r (int): Radius.
            color (int): RGB565 color value.
            rotate (Optional float): Rotation in degrees relative to origin.
        Note:
            The center point is the center of the x0,y0 pixel.
            Since pixels are not divisible, the radius is integer rounded
            up to complete on a full pixel.  Therefore diameter = 2 x r + 1.
        """
        # Determine side coordinates
        coords = []
        theta = radians(rotate)
        n = sides + 1
        for s in range(n):
            t = 2.0 * pi * s / sides + theta
            coords.append([int(r * cos(t) + x0), int(r * sin(t) + y0)])
        # Starting point
        x1, y1 = coords[0]
        # Minimum Maximum X dict
        xdict = {y1: [x1, x1]}
        # Iterate through coordinates
        for row in coords[1:]:
            x2, y2 = row
            xprev, yprev = x2, y2
            # Calculate perimeter
            # Check for horizontal side
            if y1 == y2:
                if x1 > x2:
                    x1, x2 = x2, x1
                if y1 in xdict:
                    xdict[y1] = [min(x1, xdict[y1][0]), max(x2, xdict[y1][1])]
                else:
                    xdict[y1] = [x1, x2]
                x1, y1 = xprev, yprev
                continue
            # Non horizontal side
            # Changes in x, y
            dx = x2 - x1
            dy = y2 - y1
            # Determine how steep the line is
            is_steep = abs(dy) > abs(dx)
            # Rotate line
            if is_steep:
                x1, y1 = y1, x1
                x2, y2 = y2, x2
            # Swap start and end points if necessary
            if x1 > x2:
                x1, x2 = x2, x1
                y1, y2 = y2, y1
            # Recalculate differentials
            dx = x2 - x1
            dy = y2 - y1
            # Calculate error
            error = dx >> 1
            ystep = 1 if y1 < y2 else -1
            y = y1
            # Calcualte minimum and maximum x values
            for x in range(x1, x2 + 1):
                if is_steep:
                    if x in xdict:
                        xdict[x] = [min(y, xdict[x][0]), max(y, xdict[x][1])]
                    else:
                        xdict[x] = [y, y]
                else:
                    if y in xdict:
                        xdict[y] = [min(x, xdict[y][0]), max(x, xdict[y][1])]
                    else:
                        xdict[y] = [x, x]
                error -= abs(dy)
                if error < 0:
                    y += ystep
                    error += dx
            x1, y1 = xprev, yprev
        # Fill polygon
        for y, x in xdict.items():
            self.draw_hline(x[0], y, x[1] - x[0] + 2, color)

    def fill_vrect(self, x, y, w, h, color):
        """Draw a filled rectangle (optimized for vertical drawing).

        Args:
            x (int): Starting X position.
            y (int): Starting Y position.
            w (int): Width of rectangle.
            h (int): Height of rectangle.
            color (int): RGB565 color value.
        """
        if self.is_off_grid(x, y, x + w - 1, y + h - 1):
            return
        chunk_width = 1024 // h
        chunk_count, remainder = divmod(w, chunk_width)
        chunk_size = chunk_width * h
        chunk_x = x
        if chunk_count:
            buf = color.to_bytes(2, 'big') * chunk_size
            for c in range(0, chunk_count):
                self.block(chunk_x, y,
                           chunk_x + chunk_width - 1, y + h - 1,
                           buf)
                chunk_x += chunk_width

        if remainder:
            buf = color.to_bytes(2, 'big') * remainder * h
            self.block(chunk_x, y,
                       chunk_x + remainder - 1, y + h - 1,
                       buf)

    def is_off_grid(self, xmin, ymin, xmax, ymax):
        """Check if coordinates extend past display boundaries.

        Args:
            xmin (int): Minimum horizontal pixel.
            ymin (int): Minimum vertical pixel.
            xmax (int): Maximum horizontal pixel.
            ymax (int): Maximum vertical pixel.
        Returns:
            boolean: False = Coordinates OK, True = Error.
        """
        if xmin < 0:
            print('x-coordinate: {0} below minimum of 0.'.format(xmin))
            return True
        if ymin < 0:
            print('y-coordinate: {0} below minimum of 0.'.format(ymin))
            return True
        if xmax >= self.width:
            print('x-coordinate: {0} above maximum of {1}.'.format(
                xmax, self.width - 1))
            return True
        if ymax >= self.height:
            print('y-coordinate: {0} above maximum of {1}.'.format(
                ymax, self.height - 1))
            return True
        return False

    def load_sprite(self, path, w, h):
        """Load sprite image.

        Args:
            path (string): Image file path.
            w (int): Width of image.
            h (int): Height of image.
        Notes:
            w x h cannot exceed 2048
        """
        buf_size = w * h * 2
        with open(path, "rb") as f:
            return f.read(buf_size)

    def reset_cpy(self):
        """Perform reset: Low=initialization, High=normal operation.
        Notes: CircuitPython implemntation
        """
        self.rst.value = False
        sleep(.05)
        self.rst.value = True
        sleep(.05)

    def reset_mpy(self):
        """Perform reset: Low=initialization, High=normal operation.
        Notes: MicroPython implemntation
        """
        self.rst(0)
        sleep(.05)
        self.rst(1)
        sleep(.05)

    def scroll(self, enable=True):
        """Enable or disable scrolling.

        Args:
            enable (bool): Default True
        Notes:
            It's not advisable to draw to the display during scrolling.
        """
        if enable:
            self.write_cmd(self.START_SCROLL)
        else:
            self.write_cmd(self.STOP_SCROLL)

    def set_scroll(self, horiz_offset, vert_start_row, vert_row_count,
                   vert_offset, speed):
        """Define scrolling area.

        Args:
            horiz_offset (byte): 0=None, 1-63=Left, 64-255=Right
            vert_start_row (byte): First veritcal row to scroll
            vert_row_count (byte): Number of veritical rows to scroll
            vert_offset (byte): 0:None, 1-63=Up, 64-127=Down
            speed (byte): 0=Fastest, 1=Normal, 2=Slow, 3=Slowest
        Notes:
            horiz_offset is only left, right or still (no speed).
            vert_offset controls speed in addition to direction.  1-63 is slow
            to fast (up) and 64-127 is fast to slow (down).
            There is no horizontal start row and count unlike the vertical.
            Once scrolling area is defined, use scroll method to start or stop.
        """
        if vert_start_row + vert_row_count > self.height:
            print('Start row plus row count cannot exceed display height.')
            return
        self.write_cmd(self.HORIZ_SCROLL, horiz_offset, vert_start_row,
                       vert_row_count, vert_offset, speed)

    def write_cmd_mpy(self, command, *args):
        """Write command to OLED (MicroPython).

        Args:
            command (byte): SSD1351 command code.
            *args (optional bytes): Data to transmit.
        """
        self.dc(0)
        self.cs(0)
        self.spi.write(bytearray([command]))
        self.cs(1)
        # Handle any passed data
        if len(args) > 0:
            self.write_data(bytearray(args))

    def write_cmd_cpy(self, command, *args):
        """Write command to OLED (CircuitPython).

        Args:
            command (byte): SSD1351 command code.
            *args (optional bytes): Data to transmit.
        """
        self.dc.value = False
        self.cs.value = False
        # Confirm SPI locked before writing
        while not self.spi.try_lock():
            pass
        self.spi.write(bytearray([command]))
        self.spi.unlock()
        self.cs.value = True
        # Handle any passed data
        if len(args) > 0:
            self.write_data(bytearray(args))

    def write_data_mpy(self, data):
        """Write data to OLED (MicroPython).

        Args:
            data (bytes): Data to transmit.
        """
        self.dc(1)
        self.cs(0)
        self.spi.write(data)
        self.cs(1)

    def write_data_cpy(self, data):
        """Write data to OLED (CircuitPython).

        Args:
            data (bytes): Data to transmit.
        """
        self.dc.value = True
        self.cs.value = False
        # Confirm SPI locked before writing
        while not self.spi.try_lock():
            pass
        self.spi.write(data)
        self.spi.unlock()
        self.cs.value = True