/*
 * File:   oled.c
 * Author: www.hetenko.org
 * Created on 2017/04/08, 10:32
 *
 *  Original Author Nicolas Pannwitz (http://pic-projekte.de) 
 */

#include <avr/io.h>
#include <stdio.h>
#include <string.h>
#include "oled.h"
#include "font25x32.h"

void oled_command(unsigned char command) {
	TinyI2C_start();
	TinyI2C_write(SSD1306_DEFAULT_ADDRESS);
	TinyI2C_write(0x00);
	TinyI2C_write(command);
	TinyI2C_stop();
}

void oled_init(void) {
	// Turn display off
	oled_command(SSD1306_DISPLAYOFF);
	oled_command(SSD1306_SETDISPLAYCLOCKDIV);
	oled_command(0x80);
	oled_command(SSD1306_SETMULTIPLEX);
	oled_command(0x3F);
	oled_command(SSD1306_SETDISPLAYOFFSET);
	oled_command(0x00);
	oled_command(SSD1306_SETSTARTLINE | 0x00);
	// We use internal charge pump
	oled_command(SSD1306_CHARGEPUMP);
	oled_command(0x14);
	// Horizontal memory mode
	oled_command(SSD1306_MEMORYMODE);
	oled_command(0x00);
	oled_command(SSD1306_SEGREMAP | 0x01);
	oled_command(SSD1306_COMSCANDEC);
	oled_command(SSD1306_SETCOMPINS);
	oled_command(0x12);
	// Max contrast
	oled_command(SSD1306_SETCONTRAST);
	oled_command(0x4f);
	oled_command(SSD1306_SETPRECHARGE);
	oled_command(0xF1);
	oled_command(SSD1306_SETVCOMDETECT);
	oled_command(0x40);
	oled_command(SSD1306_DISPLAYALLON_RESUME);
	// Non-inverted display
	oled_command(SSD1306_NORMALDISPLAY);
	// oled_command(SSD1306_INVERTDISPLAY);
	// Turn display back on
	oled_command(SSD1306_DISPLAYON);
}

void oled_invert(unsigned char inverted) {
	if(inverted)
		oled_command(SSD1306_INVERTDISPLAY);
	else
		oled_command(SSD1306_NORMALDISPLAY);
}

void oled_clear(void) {
	unsigned int i;
	
   	TinyI2C_start();
	TinyI2C_write(SSD1306_DEFAULT_ADDRESS);
	TinyI2C_write(0x00);
	TinyI2C_write(SSD1306_SETPAGEADDRESS);
	TinyI2C_write(SSD1306_COLUMNADDR);
	TinyI2C_write(SSD1306_SETLOWCOLUMN);
	TinyI2C_write(0x7F);
	TinyI2C_stop();
	
	TinyI2C_start();
 	TinyI2C_write(SSD1306_DEFAULT_ADDRESS);
	TinyI2C_write(0x40);
	for(i = 0; i < (SSD1306_WIDTH * SSD1306_HEIGHT / 8); i++)
		TinyI2C_write(0x00);
	TinyI2C_stop();
}

void oled_char(unsigned int x, unsigned int y, unsigned int fIndex) {
	unsigned char width;
	unsigned char height;
	unsigned char loop;
	unsigned char i, j;

	width = FONT_WIDTH;
	height = FONT_HEIGHT;
	loop = FONT_HEIGHT / 8;

	for(i = 0; i < loop; i++) {
		TinyI2C_start();
		TinyI2C_write(SSD1306_DEFAULT_ADDRESS);
		TinyI2C_write(0x00);
		TinyI2C_write(SSD1306_MEMORYMODE);
		TinyI2C_write(0x02);
		TinyI2C_write(SSD1306_SETPAGEADDRESS | y + i);
		TinyI2C_write(SSD1306_SETLOWCOLUMN | (x & 0xF));
		TinyI2C_write(SSD1306_SETHIGHCOLUMN | ((x >> 4) & 0xF));
		TinyI2C_stop();
		
		TinyI2C_start();
		TinyI2C_write(SSD1306_DEFAULT_ADDRESS);
		TinyI2C_write(0x40);
		for(j = 0; j < width; j++)
			TinyI2C_write(pgm_read_byte(&font[fIndex + j * loop + i + 1]));
		TinyI2C_stop();
	}
}

void oled_string(unsigned int x, unsigned int y, const char *pS) {
	unsigned int lIndex, k;
	unsigned char width;
	unsigned char height;

	width = FONT_WIDTH;
	height = FONT_HEIGHT;

	while(*pS) {
		lIndex = 0;
		for(k = 0; k < (*pS - ' '); k++)
			lIndex += (height / 8) * width + 1;

		oled_char(x, y, lIndex);
		x += width;
		pS++;
	}
}