/*****************************************************************************
* | File      	:   epd_3in7.c
* | Author      :   Waveshare team, Sandro
* | Function    :   3.7inch e-paper
* | Info        :
*----------------
* |	This version:   V1.1
* | Date        :   2025-09-15
* | Info        :
* -----------------------------------------------------------------------------
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documnetation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to  whom the Software is
# furished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS OR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#
******************************************************************************/

#include "epd_3in7.h"

// ===============================
// === STM32 INTEGRATION
// ===============================

extern SPI_HandleTypeDef hspi2;

void DEV_SPI_WriteByte(UBYTE value)
{
    HAL_SPI_Transmit(&hspi2, &value, 1, 1000);
}

// ===============================
// === DRIVER
// ===============================

#define EPD_CMD_GATE_SETTING 0x01
#define EPD_CMD_POWEROFF 0x02
#define EPD_CMD_SLEEP2 0x07
#define EPD_CMD_GATE_VOLTAGE 0x03
#define EPD_CMD_GATE_VOLTAGE_SOURCE 0x04
#define EPD_CMD_BOOSTER_SOFT_START_CONTROL 0x0C
#define EPD_CMD_DEEP_SLEEP 0x10
#define EPD_CMD_DATA_ENTRY_SEQUENCE 0x11
#define EPD_CMD_SW_RESET 0x12
#define EPD_CMD_TEMPERATURE_SENSOR_SELECTION 0x18
#define EPD_CMD_TEMPERATURE_SENSOR_WRITE 0x1A
#define EPD_CMD_TEMPERATURE_SENSOR_READ 0x1B
#define EPD_CMD_DISPLAY_UPDATE_SEQUENCE 0x20
#define EPD_CMD_DISPLAY_UPDATE_SEQUENCE_SETTING 0x22
#define EPD_CMD_WRITE_RAM 0x24
#define EPD_CMD_WRITE_RAM2 0x26
#define EPD_CMD_WRITE_VCOM_REGISTER 0x2C
#define EPD_CMD_WRITE_LUT_REGISTER 0x32
#define EPD_CMD_DISPLAY_OPTION 0x37
#define EPD_CMD_BORDER_WAVEFORM_CONTROL 0x3C
#define EPD_CMD_SET_RAMX_START_END 0x44
#define EPD_CMD_SET_RAMY_START_END 0x45
#define EPD_CMD_AUTO_WRITE_RED_RAM_REG_PATTERN 0x46
#define EPD_CMD_AUTO_WRITE_BW_RAM_REG_PATTERN 0x47
#define EPD_CMD_SET_RAMX_COUNTER 0x4E
#define EPD_CMD_SET_RAMY_COUNTER 0x4F
#define EPD_CMD_SLEEP 0x50

static const UBYTE lut_4Gray_GC[] =
    {
        0x2A, 0x06, 0x15, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 1
        0x28, 0x06, 0x14, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 2
        0x20, 0x06, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 3
        0x14, 0x06, 0x28, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 4
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 5
        0x00, 0x02, 0x02, 0x0A, 0x00, 0x00, 0x00, 0x08, 0x08, 0x02, // 6
        0x00, 0x02, 0x02, 0x0A, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 7
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 8
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 9
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 10
        0x22, 0x22, 0x22, 0x22, 0x22};

static const UBYTE lut_1Gray_GC[] =
    {
        0x2A, 0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 1
        0x05, 0x2A, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 2
        0x2A, 0x15, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 3
        0x05, 0x0A, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 4
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 5
        0x00, 0x02, 0x03, 0x0A, 0x00, 0x02, 0x06, 0x0A, 0x05, 0x00, // 6
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 7
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 8
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 9
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 10
        0x22, 0x22, 0x22, 0x22, 0x22};

static const UBYTE lut_1Gray_DU[] =
    {
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 1
        0x01, 0x2A, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x0A, 0x55, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 3
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 5
        0x00, 0x00, 0x05, 0x05, 0x00, 0x05, 0x03, 0x05, 0x05, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 7
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 9
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x22, 0x22, 0x22, 0x22, 0x22};

static const UBYTE lut_1Gray_A2[] =
    {
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 1
        0x0A, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 2
        0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 3
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 4
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 5
        0x00, 0x00, 0x03, 0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 6
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 7
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 8
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 9
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 10
        0x22, 0x22, 0x22, 0x22, 0x22};

/******************************************************************************
function :	Software reset
parameter:
******************************************************************************/
static void EPD_3IN7_Reset(void)
{
    DEV_Digital_Write(EPD_RST_PIN, 1);
    DEV_Delay_ms(300);
    DEV_Digital_Write(EPD_RST_PIN, 0);
    DEV_Delay_ms(3);
    DEV_Digital_Write(EPD_RST_PIN, 1);
    DEV_Delay_ms(300);
}

/******************************************************************************
function :	send command
parameter:
     Reg : Command register
******************************************************************************/
static void EPD_3IN7_SendCommand(UBYTE Reg)
{
    DEV_Digital_Write(EPD_DC_PIN, 0);
    DEV_Digital_Write(EPD_CS_PIN, 0);
    DEV_SPI_WriteByte(Reg);
    DEV_Digital_Write(EPD_CS_PIN, 1);
}

/******************************************************************************
function :	send data
parameter:
    Data : Write data
******************************************************************************/
static void EPD_3IN7_SendData(UBYTE Data)
{
    DEV_Digital_Write(EPD_DC_PIN, 1);
    DEV_Digital_Write(EPD_CS_PIN, 0);
    DEV_SPI_WriteByte(Data);
    DEV_Digital_Write(EPD_CS_PIN, 1);
}

static void EPD_3IN7_ReadBusy_HIGH(void)
{
    UBYTE busy;
    do
    {
        busy = DEV_Digital_Read(EPD_BUSY_PIN);
    } while (busy);
    DEV_Delay_ms(200);
}

/******************************************************************************
function :	set the look-up tables
parameter:
******************************************************************************/
void EPD_3IN7_Load_LUT(UBYTE lut)
{
    UWORD i;
    EPD_3IN7_SendCommand(EPD_CMD_WRITE_LUT_REGISTER);
    for (i = 0; i < 105; i++)
    {
        if (lut == 0)
            EPD_3IN7_SendData(lut_4Gray_GC[i]);
        else if (lut == 1)
            EPD_3IN7_SendData(lut_1Gray_GC[i]);
        else if (lut == 2)
            EPD_3IN7_SendData(lut_1Gray_DU[i]);
        else if (lut == 3)
            EPD_3IN7_SendData(lut_1Gray_A2[i]);
    }
}

void EPD_3IN7_4Gray_Init(void)
{
    EPD_3IN7_Reset();

    EPD_3IN7_SendCommand(EPD_CMD_SW_RESET);
    DEV_Delay_ms(300);

    EPD_3IN7_SendCommand(EPD_CMD_AUTO_WRITE_RED_RAM_REG_PATTERN);
    EPD_3IN7_SendData(0xF7);
    EPD_3IN7_ReadBusy_HIGH();
    EPD_3IN7_SendCommand(EPD_CMD_AUTO_WRITE_BW_RAM_REG_PATTERN);
    EPD_3IN7_SendData(0xF7);
    EPD_3IN7_ReadBusy_HIGH();

    EPD_3IN7_SendCommand(EPD_CMD_GATE_SETTING); // setting gaet number
    EPD_3IN7_SendData(0xDF);
    EPD_3IN7_SendData(0x01);
    EPD_3IN7_SendData(0x00);

    EPD_3IN7_SendCommand(EPD_CMD_GATE_VOLTAGE); // set gate voltage
    EPD_3IN7_SendData(0x00);

    EPD_3IN7_SendCommand(EPD_CMD_GATE_VOLTAGE_SOURCE); // set source voltage
    EPD_3IN7_SendData(0x41);
    EPD_3IN7_SendData(0xA8);
    EPD_3IN7_SendData(0x32);

    EPD_3IN7_SendCommand(EPD_CMD_DATA_ENTRY_SEQUENCE); // set data entry sequence
    EPD_3IN7_SendData(0x03);

    EPD_3IN7_SendCommand(EPD_CMD_BORDER_WAVEFORM_CONTROL); // set border
    EPD_3IN7_SendData(0x03);

    EPD_3IN7_SendCommand(EPD_CMD_BOOSTER_SOFT_START_CONTROL); // set booster strength
    EPD_3IN7_SendData(0xAE);
    EPD_3IN7_SendData(0xC7);
    EPD_3IN7_SendData(0xC3);
    EPD_3IN7_SendData(0xC0);
    EPD_3IN7_SendData(0xC0);

    EPD_3IN7_SendCommand(EPD_CMD_TEMPERATURE_SENSOR_SELECTION); // set internal sensor on
    EPD_3IN7_SendData(0x80);

    EPD_3IN7_SendCommand(EPD_CMD_WRITE_VCOM_REGISTER); // set vcom value
    EPD_3IN7_SendData(0x44);

    EPD_3IN7_SendCommand(EPD_CMD_DISPLAY_OPTION); // set display option, these setting turn on previous function
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);

    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMX_START_END); // setting X direction start/end position of RAM
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x17);
    EPD_3IN7_SendData(0x01);

    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMY_START_END); // setting Y direction start/end position of RAM
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0xDF);
    EPD_3IN7_SendData(0x01);

    EPD_3IN7_SendCommand(EPD_CMD_DISPLAY_UPDATE_SEQUENCE_SETTING); // Display Update Control 2
    EPD_3IN7_SendData(0xCF);
}

void EPD_3IN7_1Gray_Init(void)
{
    EPD_3IN7_Reset();

    EPD_3IN7_SendCommand(EPD_CMD_SW_RESET);
    DEV_Delay_ms(300);

    EPD_3IN7_SendCommand(EPD_CMD_AUTO_WRITE_RED_RAM_REG_PATTERN);
    EPD_3IN7_SendData(0xF7);
    EPD_3IN7_ReadBusy_HIGH();
    EPD_3IN7_SendCommand(EPD_CMD_AUTO_WRITE_BW_RAM_REG_PATTERN);
    EPD_3IN7_SendData(0xF7);
    EPD_3IN7_ReadBusy_HIGH();

    EPD_3IN7_SendCommand(EPD_CMD_GATE_SETTING); // setting gaet number
    EPD_3IN7_SendData(0xDF);
    EPD_3IN7_SendData(0x01);
    EPD_3IN7_SendData(0x00);

    EPD_3IN7_SendCommand(EPD_CMD_GATE_VOLTAGE); // set gate voltage
    EPD_3IN7_SendData(0x00);

    EPD_3IN7_SendCommand(EPD_CMD_GATE_VOLTAGE_SOURCE); // set source voltage
    EPD_3IN7_SendData(0x41);
    EPD_3IN7_SendData(0xA8);
    EPD_3IN7_SendData(0x32);

    EPD_3IN7_SendCommand(EPD_CMD_DATA_ENTRY_SEQUENCE); // set data entry sequence
    EPD_3IN7_SendData(0x03);

    EPD_3IN7_SendCommand(EPD_CMD_BORDER_WAVEFORM_CONTROL); // set border
    EPD_3IN7_SendData(0x03);

    EPD_3IN7_SendCommand(EPD_CMD_BOOSTER_SOFT_START_CONTROL); // set booster strength
    EPD_3IN7_SendData(0xAE);
    EPD_3IN7_SendData(0xC7);
    EPD_3IN7_SendData(0xC3);
    EPD_3IN7_SendData(0xC0);
    EPD_3IN7_SendData(0xC0);

    EPD_3IN7_SendCommand(EPD_CMD_TEMPERATURE_SENSOR_SELECTION); // set internal sensor on
    EPD_3IN7_SendData(0x80);

    EPD_3IN7_SendCommand(EPD_CMD_WRITE_VCOM_REGISTER); // set vcom value
    EPD_3IN7_SendData(0x44);

    EPD_3IN7_SendCommand(EPD_CMD_DISPLAY_OPTION); // set display option, these setting turn on previous function
    EPD_3IN7_SendData(0x00);                      // can switch 1 gray or 4 gray
    EPD_3IN7_SendData(0xFF);
    EPD_3IN7_SendData(0xFF);
    EPD_3IN7_SendData(0xFF);
    EPD_3IN7_SendData(0xFF);
    EPD_3IN7_SendData(0x4F);
    EPD_3IN7_SendData(0xFF);
    EPD_3IN7_SendData(0xFF);
    EPD_3IN7_SendData(0xFF);
    EPD_3IN7_SendData(0xFF);

    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMX_START_END); // setting X direction start/end position of RAM
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x17);
    EPD_3IN7_SendData(0x01);

    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMY_START_END); // setting Y direction start/end position of RAM
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0xDF);
    EPD_3IN7_SendData(0x01);

    EPD_3IN7_SendCommand(EPD_CMD_DISPLAY_UPDATE_SEQUENCE_SETTING); // Display Update Control 2
    EPD_3IN7_SendData(0xCF);
}

void EPD_3IN7_4Gray_Clear(void)
{
    UWORD Width, Height;
    Width = (EPD_3IN7_WIDTH % 8 == 0) ? (EPD_3IN7_WIDTH / 8) : (EPD_3IN7_WIDTH / 8 + 1);
    Height = EPD_3IN7_HEIGHT;

    EPD_3IN7_SendCommand(0x49);
    EPD_3IN7_SendData(0x00);

    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMX_COUNTER);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);

    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMY_COUNTER);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);

    EPD_3IN7_SendCommand(EPD_CMD_WRITE_RAM);
    for (UWORD j = 0; j < Height; j++)
    {
        for (UWORD i = 0; i < Width; i++)
        {
            EPD_3IN7_SendData(0xff);
        }
    }

    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMX_COUNTER);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);

    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMY_COUNTER);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);

    EPD_3IN7_SendCommand(EPD_CMD_WRITE_RAM2);
    for (UWORD j = 0; j < Height; j++)
    {
        for (UWORD i = 0; i < Width; i++)
        {
            EPD_3IN7_SendData(0xff);
        }
    }

    EPD_3IN7_Load_LUT(0);
    EPD_3IN7_SendCommand(EPD_CMD_DISPLAY_UPDATE_SEQUENCE_SETTING);
    EPD_3IN7_SendData(0xC7);

    EPD_3IN7_SendCommand(EPD_CMD_DISPLAY_UPDATE_SEQUENCE);
    EPD_3IN7_ReadBusy_HIGH();
}

void EPD_3IN7_1Gray_Clear(UBYTE mode)
{
    UWORD i;
    UWORD IMAGE_COUNTER = EPD_3IN7_WIDTH * EPD_3IN7_HEIGHT / 8;

    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMX_COUNTER);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMY_COUNTER);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);

    EPD_3IN7_SendCommand(EPD_CMD_WRITE_RAM);
    for (i = 0; i < IMAGE_COUNTER; i++)
    {
        EPD_3IN7_SendData(0xff);
    }

    EPD_3IN7_Load_LUT(mode);

    EPD_3IN7_SendCommand(EPD_CMD_DISPLAY_UPDATE_SEQUENCE);
    EPD_3IN7_ReadBusy_HIGH();
}

/******************************************************************************
function :	Sends the image buffer in RAM to e-Paper and displays
parameter:
******************************************************************************/
void EPD_3IN7_4Gray_Display(const UBYTE *Image)
{
    UDOUBLE i, j, k;
    UBYTE temp1, temp2, temp3;

    EPD_3IN7_SendCommand(0x49);
    EPD_3IN7_SendData(0x00);

    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMX_COUNTER);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);

    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMY_COUNTER);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);

    EPD_3IN7_SendCommand(EPD_CMD_WRITE_RAM);
    for (i = 0; i < 16800; i++)
    {
        temp3 = 0;
        for (j = 0; j < 2; j++)
        {
            temp1 = Image[i * 2 + j];
            for (k = 0; k < 2; k++)
            {
                temp2 = temp1 & 0xC0;
                if (temp2 == 0xC0)
                    temp3 |= 0x01; // white
                else if (temp2 == 0x00)
                    temp3 |= 0x00; // black
                else if (temp2 == 0x80)
                    temp3 |= 0x00; // gray1
                else               // 0x40
                    temp3 |= 0x01; // gray2
                temp3 <<= 1;

                temp1 <<= 2;
                temp2 = temp1 & 0xC0;
                if (temp2 == 0xC0) // white
                    temp3 |= 0x01;
                else if (temp2 == 0x00) // black
                    temp3 |= 0x00;
                else if (temp2 == 0x80)
                    temp3 |= 0x00; // gray1
                else               // 0x40
                    temp3 |= 0x01; // gray2
                if (j != 1 || k != 1)
                    temp3 <<= 1;

                temp1 <<= 2;
            }
        }
        EPD_3IN7_SendData(temp3);
    }
    // new  data
    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMX_COUNTER);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);

    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMY_COUNTER);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);

    EPD_3IN7_SendCommand(EPD_CMD_WRITE_RAM2);
    for (i = 0; i < 16800; i++)
    {
        temp3 = 0;
        for (j = 0; j < 2; j++)
        {
            temp1 = Image[i * 2 + j];
            for (k = 0; k < 2; k++)
            {
                temp2 = temp1 & 0xC0;
                if (temp2 == 0xC0)
                    temp3 |= 0x01; // white
                else if (temp2 == 0x00)
                    temp3 |= 0x00; // black
                else if (temp2 == 0x80)
                    temp3 |= 0x01; // gray1
                else               // 0x40
                    temp3 |= 0x00; // gray2
                temp3 <<= 1;

                temp1 <<= 2;
                temp2 = temp1 & 0xC0;
                if (temp2 == 0xC0) // white
                    temp3 |= 0x01;
                else if (temp2 == 0x00) // black
                    temp3 |= 0x00;
                else if (temp2 == 0x80)
                    temp3 |= 0x01; // gray1
                else               // 0x40
                    temp3 |= 0x00; // gray2
                if (j != 1 || k != 1)
                    temp3 <<= 1;

                temp1 <<= 2;
            }
        }
        EPD_3IN7_SendData(temp3);
    }

    EPD_3IN7_Load_LUT(0);

    EPD_3IN7_SendCommand(EPD_CMD_DISPLAY_UPDATE_SEQUENCE_SETTING);
    EPD_3IN7_SendData(0xC7);

    EPD_3IN7_SendCommand(EPD_CMD_DISPLAY_UPDATE_SEQUENCE);

    EPD_3IN7_ReadBusy_HIGH();
}

/******************************************************************************
function :  Sends the image buffer in RAM to e-Paper and displays
parameter:
- mode: 1: GC, 2: DU, 3: A2
******************************************************************************/
void EPD_3IN7_1Gray_Display(const UBYTE *Image, UBYTE mode)
{
    UWORD i;
    UWORD IMAGE_COUNTER = EPD_3IN7_WIDTH * EPD_3IN7_HEIGHT / 8;

    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMX_START_END);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x17);
    EPD_3IN7_SendData(0x01);

    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMY_START_END);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0xDF);
    EPD_3IN7_SendData(0x01);

    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMX_COUNTER);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);

    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMY_COUNTER);
    EPD_3IN7_SendData(0x00);
    EPD_3IN7_SendData(0x00);

    EPD_3IN7_SendCommand(EPD_CMD_WRITE_RAM);
    for (i = 0; i < IMAGE_COUNTER; i++)
    {
        EPD_3IN7_SendData(Image[i]);
    }

    EPD_3IN7_Load_LUT(mode);
    EPD_3IN7_SendCommand(EPD_CMD_DISPLAY_UPDATE_SEQUENCE);
    EPD_3IN7_ReadBusy_HIGH();
}

/******************************************************************************
function :  Sends part the image buffer in RAM to e-Paper and displays
notes:
    You can send a part of data to e-Paper,But this function is not recommended
    1. Xsize must be as big as EPD_3IN7_WIDTH
    2. Ypointer must be start at 0
******************************************************************************/
int EPD_3IN7_1Gray_Display_Part(const UBYTE *Image, UWORD Xstart, UWORD Ystart, UWORD Xend, UWORD Yend)
{
    // Sandro: Added some checks

    if (Image == NULL)
    {
        return -1; // null pointer
    }
    else if (Yend == 0 || Yend > EPD_3IN7_HEIGHT)
    {
        return -2; // invalid height
    }
    else if ((Xend - Xstart) != EPD_3IN7_WIDTH)
    {
        return -3; // width must be EPD_3IN7_WIDTH
    }
    else if (Ystart != 0)
    {
        return -4; // Ystart must be 0
    }

    UWORD i, Width;
    Width = (Xend - Xstart) % 8 == 0 ? (Xend - Xstart) / 8 : (Xend - Xstart) / 8 + 1;
    UWORD IMAGE_COUNTER = Width * (Yend - Ystart);

    Xend -= 1;
    Yend -= 1;

    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMX_START_END);
    EPD_3IN7_SendData(Xstart & 0xff);
    EPD_3IN7_SendData((Xstart >> 8) & 0x03);
    EPD_3IN7_SendData(Xend & 0xff);
    EPD_3IN7_SendData((Xend >> 8) & 0x03);
    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMY_START_END);
    EPD_3IN7_SendData(Ystart & 0xff);
    EPD_3IN7_SendData((Ystart >> 8) & 0x03);
    EPD_3IN7_SendData(Yend & 0xff);
    EPD_3IN7_SendData((Yend >> 8) & 0x03);

    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMX_COUNTER); // SET_RAM_X_ADDRESS_COUNTER
    EPD_3IN7_SendData(Xstart & 0xFF);

    EPD_3IN7_SendCommand(EPD_CMD_SET_RAMY_COUNTER); // SET_RAM_Y_ADDRESS_COUNTER
    EPD_3IN7_SendData(Ystart & 0xFF);
    EPD_3IN7_SendData((Ystart >> 8) & 0xFF);

    EPD_3IN7_SendCommand(EPD_CMD_WRITE_RAM);
    for (i = 0; i < IMAGE_COUNTER; i++)
    {
        EPD_3IN7_SendData(Image[i]);
    }

    EPD_3IN7_Load_LUT(3);
    EPD_3IN7_SendCommand(EPD_CMD_DISPLAY_UPDATE_SEQUENCE);
    EPD_3IN7_ReadBusy_HIGH();

    return 0;
}

int EPD_3IN7_1Gray_Display_Top(const UBYTE *Image, UWORD Yend_exclusive)
{
    return EPD_3IN7_1Gray_Display_Part(Image, 0, 0, EPD_3IN7_WIDTH, Yend_exclusive);
};

/******************************************************************************
function :	Enter sleep mode
parameter:
******************************************************************************/
void EPD_3IN7_Sleep(void)
{
    EPD_3IN7_SendCommand(EPD_CMD_DEEP_SLEEP); // deep sleep
    EPD_3IN7_SendData(0x03);
}