drivers_4in2.py

#     Copyright (c) 2020 Guido Kraemer
#     Copyright (c) 2018 Jouko Strömmer
#     Copyright (c) 2017 Waveshare
#
#     This program is free software: you can redistribute it and/or modify
#     it under the terms of the GNU General Public License as published by
#     the Free Software Foundation, either version 3 of the License, or
#     (at your option) any later version.
#
#     This program is distributed in the hope that it will be useful,
#     but WITHOUT ANY WARRANTY; without even the implied warranty of
#     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#     GNU General Public License for more details.
#
#     You should have received a copy of the GNU General Public License
#     along with this program.  If not, see <https://www.gnu.org/licenses/>.

from PIL import Image

from papertty.drivers.drivers_base import GPIO
from papertty.drivers.drivers_consts import EPD4in2const
from papertty.drivers.drivers_partial import WavesharePartial

# The driver works as follows:
#
# This driver is for the following display:
#     400x300, 4.2inch E-Ink display module
#     SKU: 13353
#     Part Number: 4.2inch e-Paper Module
#     Brand: Waveshare
#     UPC: 614961950887
#
# When rotating the display with side of the connector of the display (not the
# module) at the bottom, the display width is 400 and the height is 300. The
# letters on the module and the connector of the module point to the right.
#
# The origin of the display is in the top left corner and filling happens by
# line.
#
# The frame buffer is an array of bytes of size 400 * 300 / 8, each bit is one
# pixel 0 is white, 1 is black
#
# The framebuffer should always contain the entire image, redrawing happens
# only on the canged area.
#
# The properties width and height of the incoming image correspond to the
# properties of the display, access to the pixels of the image is:
# image.load[width, height]


class EPD4in2(WavesharePartial, EPD4in2const):
    """WaveShare 4.2" """

    # code adapted from  epd_4in2.c
    # https://github.com/waveshare/e-paper/blob/8973995e53cb78bac6d1f8a66c2d398c18392f71/raspberrypi%26jetsonnano/c/lib/e-paper/epd_4in2.c

    # note: this works differently (at least in the c code): there is a memory
    # buffer, the same size as the display. we partially refresh the memory
    # buffer with the image at a position and the do self.partial_refresh with
    # the entire memory buffer and the area to be refreshed.

    # note: this code is outside of drivers_partial.py because the class has to
    # override many methdos and therefore is way to long

    def __init__(self):
        super(WavesharePartial, self).__init__(name='4.2"',
                                               width=400,
                                               height=300)
        self.supports_partial = True

        # this is the memory buffer that will be updated!
        self.frame_buffer = [0x00] * (self.width * self.height // 8)

    # TODO: universal?
    def set_setting(self, command, data):
        self.send_command(command)
        self.send_data(data)
        # for d in data:
        #     self.send_data(d)

    # TODO: universal?
    def set_resolution(self):
        self.set_setting(self.RESOLUTION_SETTING,
                         [(self.width >> 8) & 0xff,
                          self.width & 0xff,
                          (self.height >> 8) & 0xff,
                          self.height & 0xff])

    def reset(self):
        self.digital_write(self.RST_PIN, GPIO.HIGH)
        self.delay_ms(200)
        self.digital_write(self.RST_PIN, GPIO.LOW)
        self.delay_ms(200)
        self.digital_write(self.RST_PIN, GPIO.HIGH)
        self.delay_ms(200)

    def send_command(self, command):
        self.digital_write(self.DC_PIN, GPIO.LOW)
        self.digital_write(self.CS_PIN, GPIO.LOW)
        self.spi_transfer([command])
        self.digital_write(self.CS_PIN, GPIO.HIGH)

    def send_data(self, data):
        self.digital_write(self.DC_PIN, GPIO.HIGH)
        self.digital_write(self.CS_PIN, GPIO.LOW)
        if type(data) == list:
            self.spi_transfer(data)
        else:
            self.spi_transfer([data])
        self.digital_write(self.CS_PIN, GPIO.HIGH)

    def wait_until_idle(self):
        self.send_command(self.GET_STATUS)
        while self.digital_read(self.BUSY_PIN) == 0:
            self.send_command(self.GET_STATUS)
            self.delay_ms(100)

    def turn_on_display(self):
        self.send_command(self.DISPLAY_REFRESH)
        self.delay_ms(100)
        self.wait_until_idle()

    def full_set_lut(self):
        self.set_setting(self.VCOM_LUT, self.LUT_VCOM0)
        self.set_setting(self.W2W_LUT, self.LUT_WW)
        self.set_setting(self.B2W_LUT, self.LUT_BW)
        self.set_setting(self.W2B_LUT, self.LUT_WB)
        self.set_setting(self.B2B_LUT, self.LUT_BB)

    def partial_set_lut(self):
        self.set_setting(self.VCOM_LUT, self.PARTIAL_LUT_VCOM1)
        self.set_setting(self.W2W_LUT, self.PARTIAL_LUT_WW1)
        self.set_setting(self.B2W_LUT, self.PARTIAL_LUT_BW1)
        self.set_setting(self.W2B_LUT, self.PARTIAL_LUT_WB1)
        self.set_setting(self.B2B_LUT, self.PARTIAL_LUT_BB1)

    def gray_set_lut(self):
        self.set_setting(self.VCOM_LUT, self.GRAY_LUT_VCOM)
        self.set_setting(self.W2W_LUT, self.GRAY_LUT_WW)
        self.set_setting(self.B2W_LUT, self.GRAY_LUT_BW)
        self.set_setting(self.W2B_LUT, self.GRAY_LUT_WB)
        self.set_setting(self.B2B_LUT, self.GRAY_LUT_BB)

    def init_bw(self):
        self.reset()
        self.set_setting(self.POWER_SETTING, [0x03, 0x00, 0x2b, 0x2b])
        self.set_setting(self.BOOSTER_SOFT_START, [0x17, 0x17, 0x17])
        self.send_command(self.POWER_ON)
        self.wait_until_idle()
        # kw-bf kwr-af bwrotp 0f bwotp 1f
        self.set_setting(self.PANEL_SETTING, [0xbf, 0x0d])
        # 3a 100hz   29 150hz 39 200hz	31 171hz
        self.set_setting(self.PLL_CONTROL, [0x3c])
        self.set_resolution()
        self.set_setting(self.VCM_DC_SETTING, [0x28])
        # wbmode: vbdf 17|d7 vbdw 97 vbdb 57
        # wbrmode:vbdf f7 vbdw 77 vbdb 37 vbdr b7
        self.set_setting(self.VCOM_AND_DATA_INTERVAL_SETTING, [0x97])
        self.full_set_lut()

    def init_gray(self):
        self.reset()
        self.set_setting(self.POWER_SETTING, [0x03, 0x00, 0x2b, 0x2b, 0x13])
        self.set_setting(self.BOOSTER_SOFT_START, [0x17, 0x17, 0x17])
        self.send_command(self.POWER_ON)
        self.wait_until_idle()
        # kw-3f  kwr-2f  bwrotp 0f  bwotp 1f
        self.set_setting(self.PANEL_SETTING, [0x3f])
        # 3a 100hz   29 150hz 39 200hz	31 171hz
        self.set_setting(self.PLL_CONTROL, [0x3c])
        self.set_resolution()
        self.set_setting(self.VCM_DC_SETTING, [0x12])
        # wbmode:vbdf 17|d7 vbdw 97 vbdb 57
        # wbrmode:vbdf f7 vbdw 77 vbdb 37 vbdr b7
        self.set_setting(self.VCOM_AND_DATA_INTERVAL_SETTING, [0x97])

    def init(self, partial=True, gray=False):
        self.partial_refresh = partial
        self.gray = gray

        if self.epd_init() != 0:
            return -1

        if self.gray:
            self.init_gray()
        else:
            self.init_bw()

    def clear(self):
        """Full refresh of the display"""

        width = int(self.width // 8)
        height = int(self.height)

        self.send_command(self.DATA_START_TRANSMISSION_1)
        for i in range(width * height):
            self.send_data(0xff)

        self.send_command(self.DATA_START_TRANSMISSION_2)
        for i in range(width * height):
            self.send_data(0xff)

        self.send_command(self.DISPLAY_REFRESH)
        self.delay_ms(10)
        self.turn_on_display()

    # Writing outside the range of the display will cause an error.
    def fill(self, color, fillsize):
        """Slow fill routine"""

        div, rem = divmod(self.height, fillsize)
        image = Image.new('1', (self.width, fillsize), color)

        for i in range(div):
            self.draw(0, i * fillsize, image)

        if rem != 0:
            image = Image.new('1', (self.width, rem), color)
            self.draw(0, div * fillsize, image)

    def display_full(self):

        # TODO: optimize this as (needs performance check):
        # self.send_command(self.DATA_START_TRANSMISSION_2, self.frame_buffer)

        width = int(self.width // 8)
        height = int(self.height)

        self.send_command(self.DATA_START_TRANSMISSION_2)
        for i in range(height):
            for j in range(width):
                self.send_data(self.frame_buffer[i * width + j])

        self.turn_on_display()

    def display_partial(self, x_start, y_start, x_end, y_end):

        width = self.width // 8

        # TODO: use x_start // 8 * 9
        x_start = int(x_start if x_start % 8 == 0 else x_start // 8 * 8 + 8)
        x_end = int(x_end if x_end % 8 == 0 else x_end // 8 * 8 + 8)

        self.set_setting(self.VCOM_AND_DATA_INTERVAL_SETTING, [0xf7])
        self.delay_ms(100)

        self.set_setting(self.VCM_DC_SETTING, [0x08])
        self.set_setting(self.VCOM_AND_DATA_INTERVAL_SETTING, [0x47])
        self.partial_set_lut()

        self.send_command(self.PARTIAL_IN)
        self.set_setting(self.PARTIAL_WINDOW,
                         [x_start     // 256, x_start     % 256,
                          (x_end - 1) // 256, (x_end - 1) % 256,
                          y_start     // 256, y_start     % 256,
                          (y_end - 1) // 256, (y_end - 1) % 256,
                          0x28])

        # writes old data to sram for programming
        self.send_command(self.DATA_START_TRANSMISSION_1)
        for j in range(y_end - y_start):
            idx = (y_start + j) * width + x_start // 8
            # TODO: optimize this by using send_data(array[from:to])
            for i in range((x_end - x_start) // 8):
                self.send_data(self.frame_buffer[idx + i])

        # writes new data to sram.
        self.send_command(self.DATA_START_TRANSMISSION_2)
        for j in range(y_end - y_start):
            idx = (y_start + j) * width + x_start // 8
            # TODO: optimize this by using send_data(array[from:to])
            for i in range((x_end - x_start) // 8):
                self.send_data(~self.frame_buffer[idx + i])

        self.send_command(self.DISPLAY_REFRESH)   # display refresh
        self.delay_ms(10)  # the delay here is necessary, 200us at least!!!
        self.turn_on_display()

    def sleep(self):
        """Put the display in deep sleep mode"""

        self.send_command(self.POWER_OFF)
        self.wait_until_idle()
        self.set_setting(self.DEEP_SLEEP, [0xa5])

    def frame_buffer_to_image(self):
        """Returns self.frame_buffer as a PIL.Image"""

        im = Image.new('1', (self.width, self.height), "white")
        pi = im.load()

        for j in range(self.height):
            idxj = j * self.width // 8
            for i in range(self.width):
                idiv, irem = divmod(i, 8)
                mask = 0b10000000 >> irem
                idxi = idiv
                pi[i, j] = self.frame_buffer[idxi + idxj] & mask

        return im

    def set_frame_buffer(self, x, y, image):
        """Updates self.frame_buffer with image at (x, y)"""

        image_monocolor = image.convert('1')
        imwidth, imheight = image_monocolor.size
        pixels = image_monocolor.load()

        for j in range(imheight):
            idxj = (y + j) * self.width // 8
            for i in range(imwidth):
                idiv, irem = divmod(x + i, 8)
                mask = 0b10000000 >> irem
                idxi = idiv
                if pixels[i, j] != 0:
                    self.frame_buffer[idxi + idxj] |= mask
                else:
                    self.frame_buffer[idxi + idxj] &= ~mask

    def draw(self, x, y, image):
        """replace a particular area on the display with an image"""

        if self.partial_refresh:
            self.set_frame_buffer(x, y, image)
            self.display_partial(x, y, x + image.width, y + image.height)
        else:
            self.set_frame_buffer(0, 0, image)
            self.display_full()