#include "LCD.h"
#include "stm32l476xx.h"
#include <stdint.h>

/* =========================================================================
                              LCD MAPPING
=========================================================================
LCD allows to display informations on six 14-segment digits and 4 bars:

1    2    3    4    5    6
----- ----- ----- ----- ----- -----
|\|/| o |\|/| o |\|/| o |\|/| o |\|/| |\|/| BAR3
-- -- -- -- -- -- -- -- -- -- -- -- BAR2
|/|\| o |/|\| o |/|\| o |/|\| o |/|\| |/|\| BAR1
----- * ----- * ----- * ----- * ----- ----- BAR0

LCD segment mapping:
--------------------
-----A-----    _
|\ | /| COL |_|
F H J K B
| \ | / |    _
--G-- --M-- COL |_|
| / | \ |
E Q P N C
|/ | \|    _
-----D----- DP |_|

An LCD character coding is based on the following matrix:
COM       0 1 2 3
SEG(n)    { E , D , P , N }
SEG(n+1) { M , C , COL , DP }
SEG(23-n-1) { B , A , K , J }
SEG(23-n) { G , F , Q , H }
with n positive odd number.

The character 'A' for example is:
-------------------------------
LSB { 1 , 0 , 0 , 0 }
   { 1 , 1 , 0 , 0 }
   { 1 , 1 , 0 , 0 }
MSB { 1 , 1 , 0 , 0 }
   -------------------
'A' = F E 0 0 hexa

@endverbati

*/

/* Constant table for cap characters 'A' --> 'Z' */
const uint16_t CapLetterMap[26] = {
   /* A    B    C    D    E    F    G    H    I */
   0xFE00,0x6714,0x1d00,0x4714,0x9d00,0x9c00,0x3f00,0xfa00,0x0014,
   /* J    K    L    M    N    O    P    Q    R */
   0x5300,0x9841,0x1900,0x5a48,0x5a09,0x5f00,0xFC00,0x5F01,0xFC01,
   /* S    T    U    V    W    X    Y    Z */
   0xAF00,0x0414,0x5b00,0x18c0,0x5a81,0x00c9,0x0058,0x05c0
};

/* Constant table for number '0' --> '9' */
const uint16_t NumberMap[10] = {
   /* 0    1    2    3    4    5    6    7    8    9 */
   0x5F00,0x4200,0xF500,0x6700,0xEa00,0xAF00,0xBF00,0x04600,0xFF00,0xEF00
};

/* Macros used for set/reset bar LCD bar */
/* LCD BAR status: We don't write directly in LCD RAM for save the bar setting */
uint8_t t_bar[2] = {0x00,0x00};

#define BAR0_ON t_bar[1] |= 8
#define BAR0_OFF t_bar[1] &= ~8
#define BAR1_ON t_bar[0] |= 8
#define BAR1_OFF t_bar[0] &= ~8
#define BAR2_ON t_bar[1] |= 2
#define BAR2_OFF t_bar[1] &= ~2
#define BAR3_ON t_bar[0] |= 2
#define BAR3_OFF t_bar[0] &= ~2

#define DOT                ((uint16_t) 0x8000 ) /* for add decimal point in string */
#define DOUBLE_DOT          ((uint16_t) 0x4000) /* for add decimal point in string */

/* code for '(' character */
#define C_OPENPARMAP       ((uint16_t) 0x0028)

/* code for ')' character */
#define C_CLOSEPARMAP       ((uint16_t) 0x0011)

/* code for 'd' character */
#define C_DMAP             ((uint16_t) 0xf300)

/* code for 'm' character */
#define C_MMAP             ((uint16_t) 0xb210)

/* code for 'n' character */
#define C_NMAP             ((uint16_t) 0x2210)

/* code for 'µ' character */
#define C_UMAP             ((uint16_t) 0x6084)

/* constant code for '*' character */
#define C_STAR             ((uint16_t) 0xA0DD)

/* constant code for '-' character */
#define C_MINUS             ((uint16_t) 0xA000)

/* constant code for '+' character */
#define C_PLUS             ((uint16_t) 0xA014)

/* constant code for '/' */
#define C_SLATCH          ((uint16_t) 0x00c0)

/* constant code for ∞ */
#define C_PERCENT_1       ((uint16_t) 0xec00)

/* constant code for small o */
#define C_PERCENT_2       ((uint16_t) 0xb300)

#define C_FULL             ((uint16_t) 0xffdd)

void LCD_Initialization(void){
LCD_PIN_Init();
LCD_Clock_Init();
LCD_Configure();
LCD_Clear();
}

void LCD_PIN_Init(void){
// LCD (24 segments, 4 commons, multiplexed 1/4 duty, 1/3 bias) on DIP28 connector
// VLCD = PC3
//
// COM0 = PA8 COM1 = PA9    COM2 = PA10 COM3 = PB9
//
// SEG0 = PA7 SEG6 = PD11 SEG12 = PB5 SEG18 = PD8
// SEG1 = PC5 SEG7 = PD13 SEG13 = PC8 SEG19 = PB14
// SEG2 = PB1 SEG8 = PD15 SEG14 = PC6 SEG20 = PB12
// SEG3 = PB13 SEG9 = PC7    SEG15 = PD14 SEG21 = PB0
// SEG4 = PB15 SEG10 = PA15 SEG16 = PD12 SEG22 = PC4
// SEG5 = PD9 SEG11 = PB4    SEG17 = PD10 SEG23 = PA6

/* Enable GPIOs clock */
RCC->AHB2ENR |= RCC_AHB2ENR_GPIOAEN | RCC_AHB2ENR_GPIOBEN | RCC_AHB2ENR_GPIOCEN | RCC_AHB2ENR_GPIODEN;

// GPIO Mode: Input(00, reset), Output(01), AlterFunc(10), Analog(11, reset)
// GPIO Speed: Low speed (00), Medium speed (01), Fast speed (10), High speed (11)
// GPIO Push-Pull: No pull-up, pull-down (00), Pull-up (01), Pull-down (10), Reserved (11)
// GPIO Output Type: Output push-pull (0, reset), Output open drain (1)

/* Configure PA 6, 7, 8, 9, 10, 15 as Alternative Function 11 (0x0B)*/
GPIOA->MODER &= ~(3U<<(2*6) | 3U<<(2*7) | 3U<<(2*8) | 3U<<(2*9) | 3U<<(2*10) | 3U<<(2*15));
GPIOA->MODER |= 2U<<(2*6) | 2U<<(2*7) | 2U<<(2*8) | 2U<<(2*9) | 2U<<(2*10) | 2U<<(2*15) ;
GPIOA->AFR[0] |= 0xBB000000;
GPIOA->AFR[1] |= 0xB0000BBB;
GPIOA->OSPEEDR &= ~(3U<<(2*6) | 3U<<(2*7) | 3U<<(2*8) | 3U<<(2*9) | 3U<<(2*10) | 3U<<(2*15));
GPIOA->OSPEEDR |= 2U<<(2*6) | 2U<<(2*7) | 2U<<(2*8) | 2U<<(2*9) | 2U<<(2*10) | 2U<<(2*15) ;
GPIOA->PUPDR &= ~(3U<<(2*6) | 3U<<(2*7) | 3U<<(2*8) | 3U<<(2*9) | 3U<<(2*10) | 3U<<(2*15));

/* Configure PB 0, 1, 4, 5, 9, 12, 13, 14, 15 as Alternative Function 11 (0x0B)*/
GPIOB->MODER &= ~(3U<<(2*0) | 3U<<(2*1) | 3U<<(2*4) | 3U<<(2*5) | 3U<<(2*9) | 3U<<(2*12)| 3U<<(2*13)| 3U<<(2*14)| 3U<<(2*15));
GPIOB->MODER |= 2U<<(2*0) | 2U<<(2*1) | 2U<<(2*4) | 2U<<(2*5) | 2U<<(2*9) | 2U<<(2*12)| 2U<<(2*13)| 2U<<(2*14)| 2U<<(2*15);
GPIOB->AFR[0] |= 0x00BB00BB;
GPIOB->AFR[1] |= 0xBBBB00B0;
GPIOB->OSPEEDR &= ~(3U<<(2*0) | 3U<<(2*1) | 3U<<(2*4) | 3U<<(2*5) | 3U<<(2*9) | 3U<<(2*12)| 3U<<(2*13)| 3U<<(2*14)| 3U<<(2*15));
GPIOB->OSPEEDR |= 2U<<(2*0) | 2U<<(2*1) | 2U<<(2*4) | 2U<<(2*5) | 2U<<(2*9) | 2U<<(2*12)| 2U<<(2*13)| 2U<<(2*14)| 2U<<(2*15);
GPIOB->PUPDR &= ~(3U<<(2*0) | 3U<<(2*1) | 3U<<(2*4) | 3U<<(2*5) | 3U<<(2*9) | 3U<<(2*12)| 3U<<(2*13)| 3U<<(2*14)| 3U<<(2*15));

/* Configure PC 3, 4, 5, 6, 7, 8 as Alternative Function 11 (0x0B)*/
// Note: PC3 = V_LCD
GPIOC->MODER &= ~(3U<<(2*3) | 3U<<(2*4) | 3U<<(2*5) | 3U<<(2*6) | 3U<<(2*7) | 3U<<(2*8));
GPIOC->MODER |= 2U<<(2*3) | 2U<<(2*4) | 2U<<(2*5) | 2U<<(2*6) | 2U<<(2*7) | 2U<<(2*8);
GPIOC->AFR[0] |= 0xBBBBB000;
GPIOC->AFR[1] |= 0x0000000B;
GPIOC->OSPEEDR &= ~(3U<<(2*3) | 3U<<(2*4) | 3U<<(2*5) | 3U<<(2*6) | 3U<<(2*7) | 3U<<(2*8));
GPIOC->OSPEEDR |= 2U<<(2*3) | 2U<<(2*4) | 2U<<(2*5) | 2U<<(2*6) | 2U<<(2*7) | 2U<<(2*8);
GPIOC->PUPDR &= ~(3U<<(2*3) | 3U<<(2*4) | 3U<<(2*5) | 3U<<(2*6) | 3U<<(2*7) | 3U<<(2*8));

/* Configure PD 8, 9, 10, 11, 12, 13, 14, 15 as Alternative Function 11 (0x0B) */
GPIOD->MODER &= ~0xFFFF0000; // ~(3U<<(2*8) | 3U<<(2*9) | 3U<<(2*10) | 3U<<(2*11) | 3U<<(2*12) | 3U<<(2*13)| 3U<<(2*14) | 3U<<(2*15));
GPIOD->MODER |= 0xAAAA0000; // 2U<<(2*8) | 2U<<(2*9) | 2U<<(2*10) | 2U<<(2*11) | 2U<<(2*12) | 2U<<(2*13)| 2U<<(2*14) | 2U<<(2*15);
GPIOD->AFR[1] |= 0xBBBBBBBB;
GPIOD->OSPEEDR &= 0xFFFF0000; // ~(3U<<(2*8) | 3U<<(2*9) | 3U<<(2*10) | 3U<<(2*11) | 3U<<(2*12) | 3U<<(2*13)| 3U<<(2*14) | 3U<<(2*15));
GPIOD->OSPEEDR |= 0xAAAA0000; // 2U<<(2*8) | 2U<<(2*9) | 2U<<(2*10) | 2U<<(2*11) | 2U<<(2*12) | 2U<<(2*13)| 2U<<(2*14) | 2U<<(2*15);
GPIOD->PUPDR &= 0xFFFF0000; // ~(3U<<(2*8) | 3U<<(2*9) | 3U<<(2*10) | 3U<<(2*11) | 3U<<(2*12) | 3U<<(2*13)| 3U<<(2*14) | 3U<<(2*15));

}

void LCD_Clock_Init(void){
// Enable write access to Backup domain
if ( (RCC->APB1ENR1 & RCC_APB1ENR1_PWREN) == 0)
RCC->APB1ENR1 |= RCC_APB1ENR1_PWREN; // Power interface clock enable
(void) RCC->APB1ENR1; // Delay after an RCC peripheral clock enabling

// Select LSE as RTC clock soucre
if ( (PWR->CR1 & PWR_CR1_DBP) == 0) {
PWR->CR1 |= PWR_CR1_DBP; // Enable write access to Backup domain
while((PWR->CR1 & PWR_CR1_DBP) == 0); // Wait for Backup domain Write protection disable
}

// Reset LSEON and LSEBYP bits before configuring the LSE
RCC->BDCR &= ~(RCC_BDCR_LSEON | RCC_BDCR_LSEBYP);

// RTC Clock selection can be changed only if the Backup Domain is reset
RCC->BDCR |= RCC_BDCR_BDRST;
RCC->BDCR &= ~RCC_BDCR_BDRST;

// Note from STM32L4 Reference Manual:
// RTC/LCD Clock: (1) LSE is in the Backup domain. (2) HSE and LSI are not.
while((RCC->BDCR & RCC_BDCR_LSERDY) == 0){ // Wait until LSE clock ready
RCC->BDCR |= RCC_BDCR_LSEON;
}

// Select LSE as RTC clock source
// BDCR = Backup Domain Control Register
RCC->BDCR &= ~RCC_BDCR_RTCSEL; // RTCSEL[1:0]: 00 = No Clock, 01 = LSE, 10 = LSI, 11 = HSE
RCC->BDCR |= RCC_BDCR_RTCSEL_0; // Select LSE as RTC clock

RCC->APB1ENR1 &= ~RCC_APB1ENR1_PWREN; // Power interface clock disable

// Wait for the external capacitor Cext which is connected to the VLCD pin is charged (approximately 2ms for Cext=1uF)

// Enable LCD peripheral Clock
RCC->APB1ENR1 |= RCC_APB1ENR1_LCDEN;

// Enable SYSCFG
// RCC->APB2ENR |= RCC_APB2ENR_SYSCFGEN;
}

void LCD_Configure(void){

LCD->CR &= ~LCD_CR_LCDEN; // Disable LCD

// LCD frame control register (FCR)
// Set clock divider
LCD->FCR |= 0xF<<18;    // DIV[3:0] = 1111, ck_div = ck_ps/31

// Set CLKPS = LCDCLK
LCD->FCR &= ~LCD_FCR_PS; // 0000: ck_ps = LCDCLK

// Blink mode selection
LCD->FCR &= ~LCD_FCR_BLINK; // 00: Blink disabled
// 01: Blink enabled on SEG[0], COM[0] (1 pixel)
// 10: Blink enabled on SEG[0], all COMs (up to 8 pixels depending on the programmed duty)
// 11: Blink enabled on all SEGs and all COMs (all pixels)
// Blink Frequency
LCD->FCR &= ~LCD_FCR_BLINKF;
LCD->FCR |= LCD_FCR_BLINKF_1; // 010: fLCD/32

// Set Pulse ON duration
// Use high drive internal booster to provide larger drive current
// Set the duration that the low-resister voltage divider is used
LCD->FCR |= 0x7 << 4; // PON[2:0] = 0x111

// Contrast Control: specify one of the VLCD maximum voltages
LCD->FCR &= ~LCD_FCR_CC; // CC[2:0] bits (Contrast Control)
LCD->FCR |= 0x5<<10; // 101: VLCD5, Refer to the product datasheet for the VLCDx values

// Pulse ON duration: A short pulse will lead to lower power consumption,
// but displays with high internal resistance may need a longer pulse to
// achieve satisfactory contrast.
LCD->FCR &= ~LCD_FCR_PON; // PON[2:0] bits (Pulse ON Duration)
LCD->FCR |= 0x4<<4; // 100: 4/ck_ps

// Waits until the LCD FCR register is synchronized in the LCDCLK domain
// This bit is set by hardware each time the LCD_FCR register is updated in the LCDCLK domain.
// It is cleared by hardware when writing to the LCD_FCR register.
while ((LCD->SR & LCD_SR_FCRSR) == 0); // Loop until FCRSF flag is set

// Select 1/4 duty
LCD->CR &= ~(LCD_CR_DUTY); // Clear duty
LCD->CR |= 0x3<<2;    // DUTY[2:0]: 000=Static; 001=1/2; 010=1/3; 011=1/4; 100=1/8

// Select 1/3 bias
LCD->CR &= ~(LCD_CR_BIAS); // Clear bias
LCD->CR |= 0x2<<5;    // BIAS[1:0]: 00=1/4; 01=1/2; 10=1/3

// MUX_SEG disabled
// 0: SEG pin multiplexing disabled
// 1: SEG[31:28] are multiplexed with SEG[43:40]
LCD->CR &= ~LCD_CR_MUX_SEG; // Disable Mux Segment;

/* LCD control register */
// VSEL: Voltage source selection
// When the LCD is based on the internal step-up converter, the VLCD pin should be connected to a capacitor (see the product datasheet for further information).
LCD->CR &= ~LCD_CR_VSEL; // 0 = internal source, 1 = external source (VLCD pin)

// LCD controller enable
// The VSEL, MUX_SEG, BIAS, DUTY and BUFEN bits are write-protected when the LCD is enabled (ENS bit in LCD_SR to 1).
// When the LCD is disabled all COM and SEG pins are driven to VSS.
LCD->CR |= LCD_CR_LCDEN; // Enable LCD
// Loop until LCD controller is enabled
while ((LCD->SR & LCD_SR_ENS) == 0); // ENS is set by hardware automatically

// Wait until the LCD Booster is ready
while ((LCD->SR & LCD_SR_RDY) == 0); // Loop until step-up converter is ready to provide the correct voltage.

// Enable the display request
LCD->SR |= LCD_SR_UDR;
}

1. Calculate Vx using source transformation method. - ms wm 302...