reflower/main/nokia.c

#include <driver/gpio.h>
#include <arch/cc.h>
#include <driver/spi_master.h>
#include "nokia.h"
#include <string.h>

/* Pin definitions:
Most of these pins can be moved to any digital or analog pin.
DN(MOSI)and SCLK should be left where they are (SPI pins). The
LED (backlight) pin should remain on a PWM-capable pin. */
static const int scePin = 17;   // SCE - Chip select, pin 3 on LCD.
static const int rstPin = 16;   // RST - Reset, pin 4 on LCD.
static const int dcPin = 4;    // DC - Data/Command, pin 5 on LCD.
static const int sdinPin = 15;  // DN(MOSI) - Serial data, pin 6 on LCD.
static const int sclkPin = 13;  // SCLK - Serial clock, pin 7 on LCD.

/* PCD8544-specific defines: */
#define LCD_COMMAND  0
#define LCD_DATA     1

static spi_device_handle_t hSPI;

/* Font table:
This table contains the hex values that represent pixels for a
font that is 5 pixels wide and 8 pixels high. Each byte in a row
represents one, 8-pixel, vertical column of a character. 5 bytes
per character. */
static const uint8_t ASCII[][5] = {
    // First 32 characters (0x00-0x19) are ignored. These are
    // non-displayable, control characters.
    {0x00, 0x00, 0x00, 0x00, 0x00} // 0x20
    ,
    {0x00, 0x00, 0x5f, 0x00, 0x00} // 0x21 !
    ,
    {0x00, 0x07, 0x00, 0x07, 0x00} // 0x22 "
    ,
    {0x14, 0x7f, 0x14, 0x7f, 0x14} // 0x23 #
    ,
    {0x24, 0x2a, 0x7f, 0x2a, 0x12} // 0x24 $
    ,
    {0x23, 0x13, 0x08, 0x64, 0x62} // 0x25 %
    ,
    {0x36, 0x49, 0x55, 0x22, 0x50} // 0x26 &
    ,
    {0x00, 0x05, 0x03, 0x00, 0x00} // 0x27 '
    ,
    {0x00, 0x1c, 0x22, 0x41, 0x00} // 0x28 (
    ,
    {0x00, 0x41, 0x22, 0x1c, 0x00} // 0x29 )
    ,
    {0x14, 0x08, 0x3e, 0x08, 0x14} // 0x2a *
    ,
    {0x08, 0x08, 0x3e, 0x08, 0x08} // 0x2b +
    ,
    {0x00, 0x50, 0x30, 0x00, 0x00} // 0x2c ,
    ,
    {0x08, 0x08, 0x08, 0x08, 0x08} // 0x2d -
    ,
    {0x00, 0x60, 0x60, 0x00, 0x00} // 0x2e .
    ,
    {0x20, 0x10, 0x08, 0x04, 0x02} // 0x2f /
    ,
    {0x3e, 0x51, 0x49, 0x45, 0x3e} // 0x30 0
    ,
    {0x00, 0x42, 0x7f, 0x40, 0x00} // 0x31 1
    ,
    {0x42, 0x61, 0x51, 0x49, 0x46} // 0x32 2
    ,
    {0x21, 0x41, 0x45, 0x4b, 0x31} // 0x33 3
    ,
    {0x18, 0x14, 0x12, 0x7f, 0x10} // 0x34 4
    ,
    {0x27, 0x45, 0x45, 0x45, 0x39} // 0x35 5
    ,
    {0x3c, 0x4a, 0x49, 0x49, 0x30} // 0x36 6
    ,
    {0x01, 0x71, 0x09, 0x05, 0x03} // 0x37 7
    ,
    {0x36, 0x49, 0x49, 0x49, 0x36} // 0x38 8
    ,
    {0x06, 0x49, 0x49, 0x29, 0x1e} // 0x39 9
    ,
    {0x00, 0x36, 0x36, 0x00, 0x00} // 0x3a :
    ,
    {0x00, 0x56, 0x36, 0x00, 0x00} // 0x3b ;
    ,
    {0x08, 0x14, 0x22, 0x41, 0x00} // 0x3c <
    ,
    {0x14, 0x14, 0x14, 0x14, 0x14} // 0x3d =
    ,
    {0x00, 0x41, 0x22, 0x14, 0x08} // 0x3e >
    ,
    {0x02, 0x01, 0x51, 0x09, 0x06} // 0x3f ?
    ,
    {0x32, 0x49, 0x79, 0x41, 0x3e} // 0x40 @
    ,
    {0x7e, 0x11, 0x11, 0x11, 0x7e} // 0x41 A
    ,
    {0x7f, 0x49, 0x49, 0x49, 0x36} // 0x42 B
    ,
    {0x3e, 0x41, 0x41, 0x41, 0x22} // 0x43 C
    ,
    {0x7f, 0x41, 0x41, 0x22, 0x1c} // 0x44 D
    ,
    {0x7f, 0x49, 0x49, 0x49, 0x41} // 0x45 E
    ,
    {0x7f, 0x09, 0x09, 0x09, 0x01} // 0x46 F
    ,
    {0x3e, 0x41, 0x49, 0x49, 0x7a} // 0x47 G
    ,
    {0x7f, 0x08, 0x08, 0x08, 0x7f} // 0x48 H
    ,
    {0x00, 0x41, 0x7f, 0x41, 0x00} // 0x49 I
    ,
    {0x20, 0x40, 0x41, 0x3f, 0x01} // 0x4a J
    ,
    {0x7f, 0x08, 0x14, 0x22, 0x41} // 0x4b K
    ,
    {0x7f, 0x40, 0x40, 0x40, 0x40} // 0x4c L
    ,
    {0x7f, 0x02, 0x0c, 0x02, 0x7f} // 0x4d M
    ,
    {0x7f, 0x04, 0x08, 0x10, 0x7f} // 0x4e N
    ,
    {0x3e, 0x41, 0x41, 0x41, 0x3e} // 0x4f O
    ,
    {0x7f, 0x09, 0x09, 0x09, 0x06} // 0x50 P
    ,
    {0x3e, 0x41, 0x51, 0x21, 0x5e} // 0x51 Q
    ,
    {0x7f, 0x09, 0x19, 0x29, 0x46} // 0x52 R
    ,
    {0x46, 0x49, 0x49, 0x49, 0x31} // 0x53 S
    ,
    {0x01, 0x01, 0x7f, 0x01, 0x01} // 0x54 T
    ,
    {0x3f, 0x40, 0x40, 0x40, 0x3f} // 0x55 U
    ,
    {0x1f, 0x20, 0x40, 0x20, 0x1f} // 0x56 V
    ,
    {0x3f, 0x40, 0x38, 0x40, 0x3f} // 0x57 W
    ,
    {0x63, 0x14, 0x08, 0x14, 0x63} // 0x58 X
    ,
    {0x07, 0x08, 0x70, 0x08, 0x07} // 0x59 Y
    ,
    {0x61, 0x51, 0x49, 0x45, 0x43} // 0x5a Z
    ,
    {0x00, 0x7f, 0x41, 0x41, 0x00} // 0x5b [
    ,
    {0x02, 0x04, 0x08, 0x10, 0x20} // 0x5c \ (keep this to escape the backslash)
    ,
    {0x00, 0x41, 0x41, 0x7f, 0x00} // 0x5d ]
    ,
    {0x04, 0x02, 0x01, 0x02, 0x04} // 0x5e ^
    ,
    {0x40, 0x40, 0x40, 0x40, 0x40} // 0x5f _
    ,
    {0x00, 0x01, 0x02, 0x04, 0x00} // 0x60 `
    ,
    {0x20, 0x54, 0x54, 0x54, 0x78} // 0x61 a
    ,
    {0x7f, 0x48, 0x44, 0x44, 0x38} // 0x62 b
    ,
    {0x38, 0x44, 0x44, 0x44, 0x20} // 0x63 c
    ,
    {0x38, 0x44, 0x44, 0x48, 0x7f} // 0x64 d
    ,
    {0x38, 0x54, 0x54, 0x54, 0x18} // 0x65 e
    ,
    {0x08, 0x7e, 0x09, 0x01, 0x02} // 0x66 f
    ,
    {0x0c, 0x52, 0x52, 0x52, 0x3e} // 0x67 g
    ,
    {0x7f, 0x08, 0x04, 0x04, 0x78} // 0x68 h
    ,
    {0x00, 0x44, 0x7d, 0x40, 0x00} // 0x69 i
    ,
    {0x20, 0x40, 0x44, 0x3d, 0x00} // 0x6a j
    ,
    {0x7f, 0x10, 0x28, 0x44, 0x00} // 0x6b k
    ,
    {0x00, 0x41, 0x7f, 0x40, 0x00} // 0x6c l
    ,
    {0x7c, 0x04, 0x18, 0x04, 0x78} // 0x6d m
    ,
    {0x7c, 0x08, 0x04, 0x04, 0x78} // 0x6e n
    ,
    {0x38, 0x44, 0x44, 0x44, 0x38} // 0x6f o
    ,
    {0x7c, 0x14, 0x14, 0x14, 0x08} // 0x70 p
    ,
    {0x08, 0x14, 0x14, 0x18, 0x7c} // 0x71 q
    ,
    {0x7c, 0x08, 0x04, 0x04, 0x08} // 0x72 r
    ,
    {0x48, 0x54, 0x54, 0x54, 0x20} // 0x73 s
    ,
    {0x04, 0x3f, 0x44, 0x40, 0x20} // 0x74 t
    ,
    {0x3c, 0x40, 0x40, 0x20, 0x7c} // 0x75 u
    ,
    {0x1c, 0x20, 0x40, 0x20, 0x1c} // 0x76 v
    ,
    {0x3c, 0x40, 0x30, 0x40, 0x3c} // 0x77 w
    ,
    {0x44, 0x28, 0x10, 0x28, 0x44} // 0x78 x
    ,
    {0x0c, 0x50, 0x50, 0x50, 0x3c} // 0x79 y
    ,
    {0x44, 0x64, 0x54, 0x4c, 0x44} // 0x7a z
    ,
    {0x00, 0x08, 0x36, 0x41, 0x00} // 0x7b {
    ,
    {0x00, 0x00, 0x7f, 0x00, 0x00} // 0x7c |
    ,
    {0x00, 0x41, 0x36, 0x08, 0x00} // 0x7d }
    ,
    {0x10, 0x08, 0x08, 0x10, 0x08} // 0x7e ~
    ,
    {0x78, 0x46, 0x41, 0x46, 0x78} // 0x7f DEL
};

/* The displayMap variable stores a buffer representation of the
pixels on our display. There are 504 total bits in this array,
same as how many pixels there are on a 84 x 48 display.

Each byte in this array covers a 8-pixel vertical block on the
display. Each successive byte covers the next 8-pixel column over
until you reach the right-edge of the display and step down 8 rows.

To update the display, we first have to write to this array, then
call the updateDisplay() function, which sends this whole array
to the PCD8544.

Because the PCD8544 won't let us write individual pixels at a
time, this is how we can make targeted changes to the display. */
static uint8_t displayMap[LCD_WIDTH * LCD_HEIGHT / 8] = {
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (0,0)->(11,7) ~ These 12 bytes cover an 8x12 block in the left corner of the display
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (12,0)->(23,7)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xE0, // (24,0)->(35,7)
    0xF0, 0xF8, 0xFC, 0xFC, 0xFE, 0xFE, 0xFE, 0xFE, 0x1E, 0x0E, 0x02, 0x00, // (36,0)->(47,7)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (48,0)->(59,7)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (60,0)->(71,7)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (72,0)->(83,7)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (0,8)->(11,15)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (12,8)->(23,15)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, // (24,8)->(35,15)
    0x0F, 0x1F, 0x3F, 0x7F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFE, 0xFC, 0xF8, // (36,8)->(47,15)
    0xF8, 0xF0, 0xF8, 0xFE, 0xFE, 0xFC, 0xF8, 0xE0, 0x00, 0x00, 0x00, 0x00, // (48,8)->(59,15)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (60,8)->(71,15)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (72,8)->(83,15)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (0,16)->(11,23)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (12,16)->(23,23)
    0x00, 0x00, 0xF8, 0xFC, 0xFE, 0xFE, 0xFF, 0xFF, 0xF3, 0xE0, 0xE0, 0xC0, // (24,16)->(35,23)
    0xC0, 0xC0, 0xE0, 0xE0, 0xF1, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // (36,16)->(47,23)
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x3E, 0x00, 0x00, 0x00, // (48,16)->(59,23)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (60,16)->(71,23)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (72,16)->(83,23)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (0,24)->(11,31)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (12,24)->(23,31)
    0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // (24,24)->(35,31)
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // (36,24)->(47,31)
    0xFF, 0xFF, 0xFF, 0x7F, 0x3F, 0x1F, 0x07, 0x01, 0x00, 0x00, 0x00, 0x00, // (48,24)->(59,31)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (60,24)->(71,31)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (72,24)->(83,31)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (0,32)->(11,39)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (12,32)->(23,39)
    0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x7F, 0x3F, 0x1F, // (24,32)->(35,39)
    0x0F, 0x0F, 0x0F, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x03, 0x03, // (36,32)->(47,39)
    0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (48,32)->(59,39)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (60,32)->(71,39)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (72,32)->(83,39)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (0,40)->(11,47)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (12,40)->(23,47)
    0x00, 0x00, 0x3F, 0x1F, 0x0F, 0x07, 0x03, 0x01, 0x00, 0x00, 0x00, 0x00, // (24,40)->(35,47)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (36,40)->(47,47)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (48,40)->(59,47)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (60,40)->(71,47)
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (72,40)->(83,47) !!! The bottom right pixel!
};

// There are two memory banks in the LCD, data/RAM and commands.
// This function sets the DC pin high or low depending, and then
// sends the data byte
static void LCD_SendBytes(bool data_or_command, const uint8_t *data, size_t len)
{
    esp_err_t ret;
    spi_transaction_t t;
    if (len == 0) return;             //no need to send anything
    memset(&t, 0, sizeof(t));       //Zero out the transaction
    t.length = len * 8;                 //Len is in bytes, transaction length is in bits.
    t.tx_buffer = data;               //Data
    t.user = (void *) data_or_command;                //D/C
    ret = spi_device_polling_transmit(hSPI, &t);  //Transmit!
    assert(ret == ESP_OK);            //Should have had no issues.
}

// There are two memory banks in the LCD, data/RAM and commands.
// This function sets the DC pin high or low depending, and then
// sends the data byte
static void LCD_SendByte(bool data_or_command, uint8_t data)
{
    esp_err_t ret;
    spi_transaction_t t;
    memset(&t, 0, sizeof(t));       //Zero out the transaction
    t.length = 8;                 // transaction length is in bits.
    t.tx_data[0] = data;               //Data
    t.flags = SPI_TRANS_USE_TXDATA;
    t.user = (void *) data_or_command;                //D/C
    ret = spi_device_polling_transmit(hSPI, &t);  //Transmit!
    assert(ret == ESP_OK);            //Should have had no issues.
}


// This function sets a pixel on displayMap to your preferred
// color. 1=Black, 0= white.
void LCD_setPixel(int x, int y, bool bw)
{
    // First, double check that the coordinate is in range.
    if ((x >= 0) && (x < LCD_WIDTH) && (y >= 0) && (y < LCD_HEIGHT)) {
        uint8_t shift = y % 8;

        if (bw) // If black, set the bit.
            displayMap[x + (y / 8) * LCD_WIDTH] |= 1 << shift;
        else   // If white clear the bit.
            displayMap[x + (y / 8) * LCD_WIDTH] &= ~(1 << shift);
    }
}

// setLine draws a line from x0,y0 to x1,y1 with the set color.
// This function was grabbed from the SparkFun ColorLCDShield
// library.
void LCD_setLine(int x0, int y0, int x1, int y1, bool bw)
{
    int dy = y1 - y0; // Difference between y0 and y1
    int dx = x1 - x0; // Difference between x0 and x1
    int stepx, stepy;

    if (dy < 0) {
        dy = -dy;
        stepy = -1;
    }
    else
        stepy = 1;

    if (dx < 0) {
        dx = -dx;
        stepx = -1;
    }
    else
        stepx = 1;

    dy <<= 1; // dy is now 2*dy
    dx <<= 1; // dx is now 2*dx
    LCD_setPixel(x0, y0, bw); // Draw the first pixel.

    if (dx > dy) {
        int fraction = dy - (dx >> 1);
        while (x0 != x1) {
            if (fraction >= 0) {
                y0 += stepy;
                fraction -= dx;
            }
            x0 += stepx;
            fraction += dy;
            LCD_setPixel(x0, y0, bw);
        }
    }
    else {
        int fraction = dx - (dy >> 1);
        while (y0 != y1) {
            if (fraction >= 0) {
                x0 += stepx;
                fraction -= dy;
            }
            y0 += stepy;
            fraction += dx;
            LCD_setPixel(x0, y0, bw);
        }
    }
}

// setRect will draw a rectangle from x0,y0 top-left corner to
// a x1,y1 bottom-right corner. Can be filled with the fill
// parameter, and colored with bw.
// This function was grabbed from the SparkFun ColorLCDShield
// library.
void LCD_setRect(int x0, int y0, int x1, int y1, bool fill, bool bw)
{
    // check if the rectangle is to be filled
    if (fill == 1) {
        int xDiff;

        if (x0 > x1)
            xDiff = x0 - x1; //Find the difference between the x vars
        else
            xDiff = x1 - x0;

        while (xDiff > 0) {
            LCD_setLine(x0, y0, x0, y1, bw);

            if (x0 > x1)
                x0--;
            else
                x0++;

            xDiff--;
        }
    }
    else {
        // best way to draw an unfilled rectangle is to draw four lines
        LCD_setLine(x0, y0, x1, y0, bw);
        LCD_setLine(x0, y1, x1, y1, bw);
        LCD_setLine(x0, y0, x0, y1, bw);
        LCD_setLine(x1, y0, x1, y1, bw);
    }
}

// setCircle draws a circle centered around x0,y0 with a defined
// radius. The circle can be black or white. And have a line
// thickness ranging from 1 to the radius of the circle.
// This function was grabbed from the SparkFun ColorLCDShield
// library.
void LCD_setCircle(int x0, int y0, int radius, bool bw, int lineThickness)
{
    for (int r = 0; r < lineThickness; r++) {
        int f = 1 - radius;
        int ddF_x = 0;
        int ddF_y = -2 * radius;
        int x = 0;
        int y = radius;

        LCD_setPixel(x0, y0 + radius, bw);
        LCD_setPixel(x0, y0 - radius, bw);
        LCD_setPixel(x0 + radius, y0, bw);
        LCD_setPixel(x0 - radius, y0, bw);

        while (x < y) {
            if (f >= 0) {
                y--;
                ddF_y += 2;
                f += ddF_y;
            }
            x++;
            ddF_x += 2;
            f += ddF_x + 1;

            LCD_setPixel(x0 + x, y0 + y, bw);
            LCD_setPixel(x0 - x, y0 + y, bw);
            LCD_setPixel(x0 + x, y0 - y, bw);
            LCD_setPixel(x0 - x, y0 - y, bw);
            LCD_setPixel(x0 + y, y0 + x, bw);
            LCD_setPixel(x0 - y, y0 + x, bw);
            LCD_setPixel(x0 + y, y0 - x, bw);
            LCD_setPixel(x0 - y, y0 - x, bw);
        }
        radius--;
    }
}

// This function will draw a char (defined in the ASCII table
// near the beginning of this sketch) at a defined x and y).
// The color can be either black (1) or white (0).
void LCD_setChar(char character, int x, int y, bool bw)
{
    uint8_t column; // temp byte to store character's column bitmap
    for (int i = 0; i < 5; i++) // 5 columns (x) per character
    {
        column = ASCII[character - 0x20][i];
        for (int j = 0; j < 8; j++) // 8 rows (y) per character
        {
            if (column & (0x01 << j)) // test bits to set pixels
                LCD_setPixel(x + i, y + j, bw);
            else
                LCD_setPixel(x + i, y + j, !bw);
        }
    }
}

// setStr draws a string of characters, calling setChar with
// progressive coordinates until it's done.
// This function was grabbed from the SparkFun ColorLCDShield
// library.
void LCD_setStr(char *dString, int x, int y, bool bw)
{
    while (*dString != 0x00) // loop until null terminator
    {
        LCD_setChar(*dString++, x, y, bw);
        x += 5;
        for (int i = y; i < y + 8; i++) {
            LCD_setPixel(x, i, !bw);
        }
        x++;
        if (x > (LCD_WIDTH - 5)) // Enables wrap around
        {
            x = 0;
            y += 8;
        }
    }
}

// This function will draw an array over the screen. (For now) the
// array must be the same size as the screen, covering the entirety
// of the display.
// Also, the array must reside in FLASH and declared with PROGMEM.
void LCD_setBitmap(const char *bitArray)
{
    for (int i = 0; i < (LCD_WIDTH * LCD_HEIGHT / 8); i++) {
        char c = bitArray[i];
        displayMap[i] = c;
    }
}

// This function clears the entire display either white (0) or
// black (1).
// The screen won't actually clear until you call updateDisplay()!
void LCD_clearDisplay(bool bw)
{
    for (int i = 0; i < (LCD_WIDTH * LCD_HEIGHT / 8); i++) {
        if (bw)
            displayMap[i] = 0xFF;
        else
            displayMap[i] = 0;
    }
}

// Helpful function to directly command the LCD to go to a
// specific x,y coordinate.
static void gotoXY(int x, int y)
{
    LCD_SendByte(LCD_COMMAND, 0x80 | x);  // Column.
    LCD_SendByte(LCD_COMMAND, 0x40 | y);  // Row.  ?
}

// This will actually draw on the display, whatever is currently
// in the displayMap array.
void LCD_updateDisplay()
{
    spi_device_acquire_bus(hSPI, portMAX_DELAY);
    gotoXY(0, 0);
    LCD_SendBytes(LCD_DATA, &displayMap[0], LCD_WIDTH * (LCD_HEIGHT / 8));
    spi_device_release_bus(hSPI);
}

// Set contrast can set the LCD Vop to a value between 0 and 127.
// 40-60 is usually a pretty good range.
void LCD_setContrast(uint8_t contrast)
{
    spi_device_acquire_bus(hSPI, portMAX_DELAY);
    LCD_SendByte(LCD_COMMAND, 0x21); //Tell LCD that extended commands follow
    LCD_SendByte(LCD_COMMAND, 0x80 | contrast); //Set LCD Vop (Contrast): Try 0xB1(good @ 3.3V) or 0xBF if your display is too dark
    LCD_SendByte(LCD_COMMAND, 0x20); //Set display mode
    spi_device_release_bus(hSPI);
}

/* There are two ways to do this. Either through direct commands
to the display, or by swapping each bit in the displayMap array.
We'll leave both methods here, comment one or the other out if
you please. */
void LCD_invertDisplay()
{
    /* Direct LCD Command option
    LCDWrite(LCD_COMMAND, 0x20); //Tell LCD that extended commands follow
    LCDWrite(LCD_COMMAND, 0x08 | 0x05); //Set LCD Vop (Contrast): Try 0xB1(good @ 3.3V) or 0xBF if your display is too dark
    LCDWrite(LCD_COMMAND, 0x20); //Set display mode  */

    /* Indirect, swap bits in displayMap option: */
    for (int i = 0; i < (LCD_WIDTH * LCD_HEIGHT / 8); i++) {
        displayMap[i] = ~displayMap[i] & 0xFF;
    }
    LCD_updateDisplay();
}

//This function is called (in irq context!) just before a transmission starts. It will
//set the D/C line to the value indicated in the user field.
void lcd_spi_pre_transfer_callback(spi_transaction_t *t)
{
    int dc = (int) t->user;
    gpio_set_level(dcPin, dc);
}

//This sends the magical commands to the PCD8544
void LCD_setup(void)
{
    gpio_config_t output = {
        .pin_bit_mask = (1<<scePin) | (1<<rstPin) | (1<<dcPin) | (1<<sdinPin) | (1<<sclkPin),
        .mode = GPIO_MODE_OUTPUT
    };
    gpio_config(&output);

    esp_err_t ret;
    spi_bus_config_t buscfg = {
        .miso_io_num=-1,
        .mosi_io_num=sdinPin,
        .sclk_io_num=sclkPin,
        .quadwp_io_num=-1,
        .quadhd_io_num=-1,
        .max_transfer_sz=LCD_WIDTH * LCD_HEIGHT, // ??? this doesnt seem to do anything in the driver
    };
    spi_device_interface_config_t devcfg = {
        .clock_speed_hz=2 * 1000 * 1000, // Hz
        // enable signal lead/lag
        .cs_ena_pretrans = 0,
        .cs_ena_posttrans = 0,
        .mode=0,                            //SPI mode 0
        .spics_io_num=scePin,               //CS pin
        .queue_size=1, // we use the polling mode, so this does not matter
        .pre_cb=lcd_spi_pre_transfer_callback,  //Specify pre-transfer callback to handle D/C line
    };

    //Initialize the SPI bus
    ret = spi_bus_initialize(HSPI_HOST, &buscfg, 1);
    ESP_ERROR_CHECK(ret);
    //Attach the LCD to the SPI bus
    ret = spi_bus_add_device(HSPI_HOST, &devcfg, &hSPI);
    ESP_ERROR_CHECK(ret);

    spi_device_acquire_bus(hSPI, portMAX_DELAY);

    //Reset the LCD to a known state
    gpio_set_level(rstPin, 0);
    gpio_set_level(rstPin, 1);

    const uint8_t magic[6] = {
        0x21, // Tell LCD extended commands follow
        0xB0, // Set LCD Vop (Contrast)
        0x04, // Set Temp coefficent
        0x14, // LCD bias mode 1:48 (try 0x13)
        //We must send 0x20 before modifying the display control mode
        0x20, // Clear extended option
        0x0C, // Set display control, normal mode.
    };
    LCD_SendBytes(LCD_COMMAND, &magic[0], 6);

    spi_device_release_bus(hSPI);
}