lcd.c

专门针对avr系列的单片机优化的fft算法

// the driver for LCD 128x64

#include "LCD.h"
#include "ffft.h"
#include "uart.h"

// all data to be displayed are written to vram first, then
//   the content of vram are sent to LCD by calling lcd_update()
unsigned char vram[SCR_PAGE][SCR_WIDTH];
unsigned char ram_page, ram_y;

volatile unsigned char backlight;

void lcd_delay_us (unsigned int us)
{
	unsigned int i, j;
	
	for (i = 0; i < us; i++)
	{
		j = 16;	// 16MHz osc
		while(j--);
	}
}

void lcd_write_cmd (unsigned char cmd)
{
	WRITE_CMD;
	DATA_PORT = cmd;
	LCD_EN;
	LCD_EN;
}

void lcd_write_data (unsigned char data)
{
	WRITE_DATA;	
	DATA_PORT = data;
	LCD_EN;
	LCD_EN;
}

void lcd_update (void)
{
	unsigned char i, j;
	
	for (i = 0; i < SCR_PAGE; i++)
	{	
		LEFT_SCREEN;	// writing on the left-half screen
		lcd_write_cmd(PAGE_BASE + i);
		lcd_write_cmd(Y_BASE);
		for (j = 0; j < SCR_HALF_WIDTH; j++)
		{
			lcd_write_data(vram[i][j]);
		}

		RIGHT_SCREEN;	// writing on the right-half screen
		lcd_write_cmd(PAGE_BASE + i);
		lcd_write_cmd(Y_BASE);
		for (j = SCR_HALF_WIDTH; j < SCR_WIDTH; j++)
		{
			lcd_write_data(vram[i][j]);
		}		
	}
}

void lcd_cls (void)
{
	unsigned char page, y;
	
	for (page = 0; page < SCR_PAGE; page++)
	{
		for (y = 0; y < SCR_WIDTH; y++)
		{
			vram[page][y] = 01+page;
		}
	}
	lcd_update();
}

void lcd_initial (void)
{
	LCD_RST;
	
	backlight = 1;
	BKLIGHT;
	
	CTRL_DDR = 0xFF;	// output
	DATA_DDR = 0xFF;	// output
//*
	LEFT_SCREEN;
	lcd_write_cmd(DISPLAY_ON);
	lcd_write_cmd(LINE_BASE);
	RIGHT_SCREEN;
	lcd_write_cmd(DISPLAY_ON);
	lcd_write_cmd(LINE_BASE);
//*/

	lcd_cls();
	ram_page = 0;
	ram_y = 0;
	
	print("LCD initialized.\r\n");
}

void lcd_print_point (unsigned char y, unsigned int value)//, unsigned char style)	// y: 0 ~ 127, value: 0 ~ 1023
{
	unsigned char page, index, i;
	
	for (i = T_START_PAGE; i<=T_END_PAGE; i++)
	{
		vram[i][y] = 0;	// clear this column
	}
	
	if (value > 1023)
	{
		value = 1023;
	}
	
	page = T_END_PAGE;	
	while (value > T_PAGE_VALUE)
	{
		page--;
		value-=T_PAGE_VALUE;
	}
	index = 0x80;
	while (value > T_DOT_VALUE)
	{
		index>>=1;
		value-=T_DOT_VALUE;
	}
	
	vram[page][y] = index;

	lcd_update();
}

void lcd_print_column (unsigned char y, unsigned int value)//, unsigned char style)	// y: 0 ~ 127, value: 0 ~ 1023
{
	unsigned char page, index, i;
	
	for (i = F_START_PAGE; i<=F_END_PAGE; i++)
	{
		vram[i][y] = 0;	// clear this column
	}

	if (value > 1023)
	{
		value = 1023;
	}
	
	page = F_END_PAGE;	
	while (value > F_PAGE_VALUE)
	{
		vram[page][y] = 0xFF;
		page--;
		value-=F_PAGE_VALUE;
	}
	i = 1;
	index = 0xFF;
	while (value > F_DOT_VALUE)
	{
		i++;
		value-=F_DOT_VALUE;
	}
	index<<=(8 - i);	

	vram[page][y] = index;

	lcd_update();
}

void lcd_print_signal (unsigned int *wave)
{
	unsigned int i;
	
	for (i = 0; i < FFT_N/2; i++) // compress ghe signal wave form to a half for display
	{
		lcd_print_point(i, *wave);
		wave+=2;
	}
	
	lcd_update();
}

void lcd_print_spectrum (unsigned int *spectrum)
{
	unsigned int i;
	
	for (i = 0; i < FFT_N/2; i++)
	{
		lcd_print_column(i, *spectrum);
		spectrum++;
	}

	lcd_update();
}