LCDMod.c

/***Helper module for writing to LCD inputs and controlling RGB LED strip from shift register***/

// the common headers for C99 types 
#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>

// the headers to access the GPIO subsystem
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "inc/hw_gpio.h"
#include "inc/hw_sysctl.h"

// the headers to access the TivaWare Library
#include "driverlib/sysctl.h"
#include "driverlib/pin_map.h"
#include "driverlib/gpio.h"
#include "driverlib/timer.h"
#include "driverlib/interrupt.h"

#include "BITDEFS.H"
#include "termio.h"

// headers for user-defined modules
#include "SR_for_LCD.h"
#include "LCDmod.h"

// module level defines
#define LCD_COMMAND 0
#define LCD_DATA    1

// A variable for the last 8 bits written to the shift register
static uint8_t ShiftRegisterImage;

// place to keep track of which register we are writing to
static uint8_t RegisterSelect;

/**************************************************************
Function: LCD_HWInit
Takes: nothing
Returns: nothing
Purpose: initializes shift register connected to LCD
/*************************************************************/
void LCD_HWInit(void){
	SR_Init_LCD();
}

/**************************************************************
Function: LCD_RegisterSelect
Takes: 8 bit integer
Returns: nothing
Purpose: passes input parameter to RegisterSelect variable
/*************************************************************/
static void LCD_RegisterSelect(uint8_t WhichReg){ //WhichReg is either LCD_COMMAND or LCD_DATA
	RegisterSelect = WhichReg ;
}

/**************************************************************
Function: LCD_SetData4
Takes: 8 bit integer
Returns: nothing
Purpose: sets 4 bits of data at the input to the LCD
/*************************************************************/
static void LCD_SetData4(uint8_t NewData){
	// get the current value of the port so that we can preserve the other bit states
	uint8_t CurrentValue;
	CurrentValue = SR_GetCurrentRegister_LCD();
	// insert the current state of RegisterSelect into bit 6
	if (RegisterSelect == LCD_COMMAND){
		CurrentValue &= BIT6LO;
	}
	else {
		CurrentValue |= BIT6HI;
	}
	// clear 4 LSB, while preserving 4 MSB
	CurrentValue &= (BIT7HI|BIT6HI|BIT5HI|BIT4HI); 
	// OR currentvalue with 4LSB of NewData
	CurrentValue |= (NewData & (BIT0HI|BIT1HI|BIT2HI|BIT3HI)); 
	// write data into register
	SR_Write_LCD(CurrentValue);
}

/**************************************************************
Function: LCD_PulseEnable
Takes: nothing
Returns: nothing
Purpose: pulses enable clock on LCD
/*************************************************************/
static void LCD_PulseEnable(void){
	uint8_t ThisValue;
	// get the current value of the port so that we can preserve the other bit states
	ThisValue = SR_GetCurrentRegister_LCD();
	// pulse enable line high
	SR_Write_LCD(ThisValue | BIT7HI);
	// pulse enable line low
	SR_Write_LCD(ThisValue & BIT7LO);
}

/**************************************************************
Function: LCD_Write4
Takes: 8 bit integer
Returns: nothing
Purpose: Writes a 4 bit nibble to LCD
/*************************************************************/
static void LCD_Write4(uint8_t NewData){
	// put the 4 bits of data onto the LCD data lines
	LCD_SetData4(NewData);
	// pulse the enable line to complete the write
	LCD_PulseEnable();
}

/**************************************************************
Function: LCD_Write8v2 (version 2 of LCD_Write8)
Takes: 8 bit integer
Returns: nothing
Purpose: Writes an 8 bit nibble of data to LCD.
/*************************************************************/
static void LCD_Write8v2(uint8_t NewData){
	// Shift 4MSB into 4LSB positions
	uint8_t NewDataMSB = NewData>>4;
	// Write nibble to LCD
	LCD_Write4(NewDataMSB);
	// Mask NewData to get 4LSB
	uint8_t NewDataLSB = NewData&0xff; // Mask for 4 LSB
	// Write nibble to LCD
	LCD_Write4(NewDataLSB);
}

/**************************************************************
Function: LCD_WriteCommand4
Takes: 8 bit integer
Returns: nothing
Purpose: Writes a 4 bit nibble to the LCD in the form of a command.
/*************************************************************/
void LCD_WriteCommand4(uint8_t NewData){
	// Clear the register select bit
	LCD_RegisterSelect(LCD_COMMAND);
	// Write the 4LSB to the shift register
	LCD_Write4(NewData);
}

/**************************************************************
Function: LCD_WriteCommand8
Takes: 8 bit integer
Returns: nothing
Purpose: Writes an 8 bit command to the LCD via two 4 bit nibbles.
/*************************************************************/
void LCD_WriteCommand8(uint8_t NewData){
	// Clear the register select bit
	LCD_RegisterSelect(LCD_COMMAND);
	// Write 8 bit command to LCD
	LCD_Write8v2(NewData);
}

/**************************************************************
Function: LCD_WriteData8
Takes: 8 bit integer
Returns: nothing
Purpose: Writes 8 bits of data to the LCD via two 4 bit nibbles.
/*************************************************************/
void LCD_WriteData8(uint8_t NewData){
	// Set the register select bit high
	LCD_RegisterSelect(LCD_DATA);
	// Write 8 bits of data to the shift register via two 4 bit nibbles
	LCD_Write8v2(NewData);
}

/******** THE FOLLOWING FUNCTIONS SUPPORT THE RGB LED STRIP USED IN CELEBRATION MODE********/

/**************************************************************
Function: LCD_RedLEDOn
Takes: nothing
Returns: nothing
Purpose: Turn on red LEDs on RGB LED strip.
/*************************************************************/
void LCD_RedLEDOn( void ) { //Using Bit 4 i.e. Q3 or QD
	// Initialize CurrentValue variable
	uint8_t CurrentValue;
	// Get current image of shift register data lines
	ShiftRegisterImage = SR_GetCurrentRegister_LCD();
	// Set bit 4 high on shift register without altering LCD inputs
	CurrentValue = ShiftRegisterImage | 0x10; 
	// Write this to shift register outputs
	SR_Write_LCD(CurrentValue);
}

/**************************************************************
Function: LCD_RedLEDOff
Takes: nothing
Returns: nothing
Purpose: Turn off red LEDs on RGB LED strip.
/*************************************************************/
void LCD_RedLEDOff( void ) { //Using Bit 4 i.e. Q3 or QD
	// Initialize CurrentValue variable
	uint8_t CurrentValue;
	// Get current image of shift register data lines
	ShiftRegisterImage = SR_GetCurrentRegister_LCD();
	// Set bit 4 low on shift register without altering LCD inputs
	CurrentValue = ShiftRegisterImage & ~0x10;
	// Write this to shift register outputs
	SR_Write_LCD(CurrentValue);
}

/**************************************************************
Function: LCD_BlueLEDOn
Takes: nothing
Returns: nothing
Purpose: Turn on blue LEDs on RGB LED strip.
/*************************************************************/
void LCD_BlueLEDOn( void ) { //Using Bit 5 i.e. Q2 or QC
	// Initialize CurrentValue variable
	uint8_t CurrentValue;
	// Get current image of shift register data lines
	ShiftRegisterImage = SR_GetCurrentRegister_LCD();
	// Set bit 5 high on shift register without altering LCD inputs
	CurrentValue = ShiftRegisterImage | 0x20;
	// Write this to shift register outputs
	SR_Write_LCD(CurrentValue);
}

/**************************************************************
Function: LCD_BlueLEDOff
Takes: nothing
Returns: nothing
Purpose: Turn off blue LEDs on RGB LED strip.
/*************************************************************/
void LCD_BlueLEDOff( void ) { //Using Bit 5 i.e. Q2 or QC
	// Initialize CurrentValue variable
	uint8_t CurrentValue;
	// Get current image of shift register data lines
	ShiftRegisterImage = SR_GetCurrentRegister_LCD();
	// Set bit 5 low on shift register without altering LCD inputs
	CurrentValue = ShiftRegisterImage & ~0x20;
	// Write this to shift register outputs
	SR_Write_LCD(CurrentValue);
}