/*
$Id:$

ST7565 LCD library!

Copyright (C) 2010 Limor Fried, Adafruit Industries

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

// some of this code was written by <cstone@pobox.com> originally; it is in the public domain.
*/

//#include <Wire.h>
#include <avr/pgmspace.h>
#include <WProgram.h>
#include <util/delay.h>
#include <stdlib.h>

#include "ST7565.h"

uint8_t is_reversed = 0;

// a handy reference to where the pages are on the screen
const uint8_t pagemap[] = { 3, 2, 1, 0, 7, 6, 5, 4 };

// a 5x7 font table
extern uint8_t PROGMEM font[];

// the memory buffer for the LCD
static uint8_t buffer[1024] = { 
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 

0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 
0x0, 0x0, 0x0, 0x3, 0x7, 0xF, 0x1F, 0x1F, 0x3F, 0x3F, 0x3F, 0x3F, 0x7, 0x0, 0x0, 0x0, 
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 
0x0, 0x0, 0x7F, 0x3F, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 
0x0, 0x0, 0x1F, 0x3F, 0x70, 0x70, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x6, 0x6, 0x0, 0x0, 0x0, 0x3, 0x3, 
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 

0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0xF, 0x7, 0x7, 
0x7, 0x3F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFE, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x3E, 0x0, 0x0, 
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xF, 0x3F, 
0x70, 0x60, 0x60, 0x60, 0x60, 0x30, 0x7F, 0x3F, 0x0, 0x0, 0x1F, 0x3F, 0x70, 0x60, 0x60, 0x60, 
0x60, 0x39, 0xFF, 0xFF, 0x0, 0x6, 0x1F, 0x39, 0x60, 0x60, 0x60, 0x60, 0x30, 0x3F, 0x7F, 0x0, 
0x0, 0x60, 0xFF, 0xFF, 0x60, 0x60, 0x0, 0x7F, 0x7F, 0x70, 0x60, 0x60, 0x40, 0x0, 0x7F, 0x7F, 
0x0, 0x0, 0x0, 0x0, 0x7F, 0x7F, 0x0, 0x0, 0x0, 0x7F, 0x7F, 0x0, 0x0, 0x60, 0xFF, 0xFF, 
0x60, 0x60, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 

0x80, 0xF8, 0xFC, 0xFE, 0xFE, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xEF, 0xE7, 0xE7, 0xE3, 
0xF3, 0xF9, 0xFF, 0xFF, 0xFF, 0xF7, 0x7, 0x1F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x7F, 0xFF, 
0x7F, 0x7F, 0x7F, 0x7F, 0x7F, 0x7F, 0x3F, 0x3F, 0x1F, 0xF, 0x7, 0x3, 0x0, 0x0, 0x0, 0xC0, 
0xE0, 0x60, 0x20, 0x20, 0x60, 0xE0, 0xE0, 0xE0, 0x0, 0x0, 0x80, 0xC0, 0xE0, 0x60, 0x20, 0x60, 
0x60, 0xE0, 0xE0, 0xE0, 0x0, 0x0, 0x80, 0xC0, 0x60, 0x60, 0x20, 0x60, 0x60, 0xE0, 0xE0, 0x0, 
0x0, 0x0, 0xE0, 0xE0, 0x0, 0x0, 0x0, 0xE0, 0xE0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x80, 0xE0, 
0x60, 0x60, 0x60, 0x60, 0xE0, 0x80, 0x0, 0x0, 0x0, 0xE0, 0xE0, 0x0, 0x0, 0x0, 0xE0, 0xE0, 
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 

0x0, 0x0, 0x0, 0x3, 0x7, 0x1F, 0x9F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFD, 0xF1, 0xE3, 
0xE3, 0xCF, 0xFF, 0xFF, 0xFF, 0xFF, 0xF0, 0xFC, 0x7F, 0x3F, 0x3F, 0x3F, 0x3F, 0x7F, 0xFF, 0xFF, 
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFE, 0xFC, 0xF0, 0xE0, 0x80, 0x0, 0x0, 0x0, 0xC, 
0x1C, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x7F, 0x7F, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x7, 0x7, 0x0, 
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1C, 0xC, 0x0, 0x0, 0x0, 0x0, 0x0, 
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 

0x0, 0x7, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFE, 0xFE, 0xFE, 0xFE, 0xFC, 0xF8, 
0xF8, 0xF0, 0xFE, 0xFF, 0xFF, 0xFF, 0x7F, 0x3F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x1F, 
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xFF, 
0xFF, 0x0, 0x0, 0x0, 0xFF, 0xFF, 0xE0, 0xC0, 0xC0, 0xC0, 0xFF, 0x7F, 0x0, 0x0, 0x1E, 0x7F, 
0xE1, 0xC0, 0xC0, 0xC0, 0xC0, 0x61, 0xFF, 0xFF, 0x0, 0x0, 0xFE, 0xFF, 0x1, 0x0, 0x0, 0x0, 
0xFF, 0xFF, 0x0, 0x0, 0x21, 0xF9, 0xF8, 0xDC, 0xCC, 0xCF, 0x7, 0x0, 0xC0, 0xFF, 0xFF, 0xC0, 
0x80, 0x0, 0xFF, 0xFF, 0xC0, 0xC0, 0x80, 0x0, 0x0, 0xFF, 0xFF, 0x0, 0x0, 0x1F, 0x7F, 0xF9, 
0xC8, 0xC8, 0xC8, 0xC8, 0x79, 0x39, 0x0, 0x0, 0x71, 0xF9, 0xD8, 0xCC, 0xCE, 0x47, 0x3, 0x0, 

0x0, 0x0, 0x0, 0x0, 0x80, 0x80, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 
0x0, 0x0, 0x0, 0x80, 0xC0, 0xE0, 0xF0, 0xF8, 0xF8, 0xFC, 0xFC, 0xFC, 0xFC, 0xF8, 0xF0, 0xC0, 
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xC0, 
0xC0, 0x0, 0x0, 0x0, 0xC0, 0xC0, 0x0, 0x0, 0x0, 0x0, 0xC0, 0xC0, 0x0, 0x0, 0x0, 0x80, 
0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0x80, 0xC0, 0xC0, 0x0, 0x0, 0x0, 0x80, 0xC0, 0xC0, 0xC0, 0xC0, 
0xC0, 0x80, 0x0, 0x0, 0x80, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0x0, 0x0, 0x0, 0xC0, 0xC0, 0x0, 
0x0, 0x0, 0xC0, 0x80, 0x0, 0x0, 0x0, 0x0, 0x0, 0xC0, 0xC0, 0x0, 0x0, 0x0, 0x80, 0xC0, 
0xC0, 0xC0, 0xC0, 0xC0, 0x80, 0x80, 0x0, 0x0, 0x80, 0xC0, 0xC0, 0xC0, 0xC0, 0x80, 0x0, 0x0, 

0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,};


void ST7565::drawbitmap(uint8_t x, uint8_t y, 
			const uint8_t *bitmap, uint8_t w, uint8_t h,
			uint8_t color) {
  for (uint8_t j=0; j<h; j++) {
    for (uint8_t i=0; i<w; i++ ) {
      if (pgm_read_byte(bitmap + i + (j/8)*w) & _BV(j%8)) {
	setpixel(x+i, y+j, color);
      }
    }
  }
}

void ST7565::drawstring(uint8_t x, uint8_t line, char *c) {
  while (c[0] != 0) {
    drawchar(x, line, c[0]);
    c++;
    x += 6; // 6 pixels wide
    if (x + 6 >= LCDWIDTH) {
      x = 0;    // ran out of this line
      line++;
    }
    if (line >= (LCDHEIGHT/8))
      return;        // ran out of space :(
  }

}

void  ST7565::drawchar(uint8_t x, uint8_t line, char c) {
  for (uint8_t i =0; i<5; i++ ) {
    buffer[x + (line*128) ] = pgm_read_byte(font+(c*5)+i);
    x++;
  }
}


// bresenham's algorithm - thx wikpedia
void ST7565::drawline(uint8_t x0, uint8_t y0, uint8_t x1, uint8_t y1, 
		      uint8_t color) {
  uint8_t steep = abs(y1 - y0) > abs(x1 - x0);
  if (steep) {
    swap(x0, y0);
    swap(x1, y1);
  }

  if (x0 > x1) {
    swap(x0, x1);
    swap(y0, y1);
  }

  uint8_t dx, dy;
  dx = x1 - x0;
  dy = abs(y1 - y0);

  int8_t err = dx / 2;
  int8_t ystep;

  if (y0 < y1) {
    ystep = 1;
  } else {
    ystep = -1;}

  for (; x0<x1; x0++) {
    if (steep) {
      setpixel(y0, x0, color);
    } else {
      setpixel(x0, y0, color);
    }
    err -= dy;
    if (err < 0) {
      y0 += ystep;
      err += dx;
    }
  }
}

// filled rectangle
void ST7565::fillrect(uint8_t x, uint8_t y, uint8_t w, uint8_t h, 
		      uint8_t color) {

  // stupidest version - just pixels - but fast with internal buffer!
  for (uint8_t i=x; i<x+w; i++) {
    for (uint8_t j=y; j<y+h; j++) {
      setpixel(i, j, color);
    }
  }
}

// draw a rectangle
void ST7565::drawrect(uint8_t x, uint8_t y, uint8_t w, uint8_t h, 
		      uint8_t color) {
  // stupidest version - just pixels - but fast with internal buffer!
  for (uint8_t i=x; i<x+w; i++) {
    setpixel(i, y, color);
    setpixel(i, y+h-1, color);
  }
  for (uint8_t i=y; i<y+h; i++) {
    setpixel(x, i, color);
    setpixel(x+w-1, i, color);
  } 
}

// draw a circle outline
void ST7565::drawcircle(uint8_t x0, uint8_t y0, uint8_t r, 
			uint8_t color) {
  int8_t f = 1 - r;
  int8_t ddF_x = 1;
  int8_t ddF_y = -2 * r;
  int8_t x = 0;
  int8_t y = r;

  setpixel(x0, y0+r, color);
  setpixel(x0, y0-r, color);
  setpixel(x0+r, y0, color);
  setpixel(x0-r, y0, color);

  while (x<y) {
    if (f >= 0) {
      y--;
      ddF_y += 2;
      f += ddF_y;
    }
    x++;
    ddF_x += 2;
    f += ddF_x;
  
    setpixel(x0 + x, y0 + y, color);
    setpixel(x0 - x, y0 + y, color);
    setpixel(x0 + x, y0 - y, color);
    setpixel(x0 - x, y0 - y, color);
    
    setpixel(x0 + y, y0 + x, color);
    setpixel(x0 - y, y0 + x, color);
    setpixel(x0 + y, y0 - x, color);
    setpixel(x0 - y, y0 - x, color);
    
  }
}

void ST7565::fillcircle(uint8_t x0, uint8_t y0, uint8_t r, 
			uint8_t color) {
  int8_t f = 1 - r;
  int8_t ddF_x = 1;
  int8_t ddF_y = -2 * r;
  int8_t x = 0;
  int8_t y = r;

  for (uint8_t i=y0-r; i<=y0+r; i++) {
    setpixel(x0, i, color);
  }

  while (x<y) {
    if (f >= 0) {
      y--;
      ddF_y += 2;
      f += ddF_y;
    }
    x++;
    ddF_x += 2;
    f += ddF_x;
  
    for (uint8_t i=y0-y; i<=y0+y; i++) {
      setpixel(x0+x, i, color);
      setpixel(x0-x, i, color);
    } 
    for (uint8_t i=y0-x; i<=y0+x; i++) {
      setpixel(x0+y, i, color);
      setpixel(x0-y, i, color);
    }    
  }
}

// the most basic function, set a single pixel
void ST7565::setpixel(uint8_t x, uint8_t y, uint8_t color) {
  if ((x >= LCDWIDTH) || (y >= LCDHEIGHT))
    return;

  // x is which column
  if (color) 
    buffer[x+ (y/8)*128] |= _BV(7-(y%8));  
  else
    buffer[x+ (y/8)*128] &= ~_BV(7-(y%8)); 
}


void ST7565::st7565_init(void) {
  // set pin directions
  pinMode(sid, OUTPUT);
  pinMode(sclk, OUTPUT);
  pinMode(a0, OUTPUT);
  pinMode(rst, OUTPUT);
  pinMode(cs, OUTPUT);

  // toggle RST low to reset; CS low so it'll listen to us
  if (cs > 0)
    digitalWrite(cs, LOW);

  digitalWrite(rst, LOW);
  _delay_ms(500);
  digitalWrite(rst, HIGH);

  // LCD bias select
  st7565_command(CMD_SET_BIAS_7);
  // ADC select
  st7565_command(CMD_SET_ADC_NORMAL);
  // SHL select
  st7565_command(CMD_SET_COM_NORMAL);
  // Initial display line
  st7565_command(CMD_SET_DISP_START_LINE);

  // turn on voltage converter (VC=1, VR=0, VF=0)
  st7565_command(CMD_SET_POWER_CONTROL | 0x4);
  // wait for 50% rising
  _delay_ms(50);

  // turn on voltage regulator (VC=1, VR=1, VF=0)
  st7565_command(CMD_SET_POWER_CONTROL | 0x6);
  // wait >=50ms
  _delay_ms(50);

  // turn on voltage follower (VC=1, VR=1, VF=1)
  st7565_command(CMD_SET_POWER_CONTROL | 0x7);
  // wait
  _delay_ms(10);

  // set lcd operating voltage (regulator resistor, ref voltage resistor)
  st7565_command(CMD_SET_RESISTOR_RATIO | 0x6);

  // initial display line
  // set page address
  // set column address
  // write display data
}

inline void ST7565::spiwrite(uint8_t c) {
  shiftOut(sid, sclk, MSBFIRST, c);
  /*
  int8_t i;
  for (i=7; i>=0; i--) {
    SCLK_PORT &= ~_BV(SCLK);
    if (c & _BV(i))
      SID_PORT |= _BV(SID);
    else
      SID_PORT &= ~_BV(SID);
    SCLK_PORT |= _BV(SCLK);
  }
  */

  /*
  // loop unwrapped! too fast doesnt work :(
 
  SCLK_PORT &= ~_BV(SCLK);
  if (c & _BV(7))
    SID_PORT |= _BV(SID);
  else
    SID_PORT &= ~_BV(SID);
  SCLK_PORT |= _BV(SCLK);

  SCLK_PORT &= ~_BV(SCLK);
  if (c & _BV(6))
    SID_PORT |= _BV(SID);
  else
    SID_PORT &= ~_BV(SID);
  SCLK_PORT |= _BV(SCLK);
 
  SCLK_PORT &= ~_BV(SCLK);
  if (c & _BV(5))
    SID_PORT |= _BV(SID);
  else
    SID_PORT &= ~_BV(SID);
  SCLK_PORT |= _BV(SCLK);

  SCLK_PORT &= ~_BV(SCLK);
  if (c & _BV(4))
    SID_PORT |= _BV(SID);
  else
    SID_PORT &= ~_BV(SID);
  SCLK_PORT |= _BV(SCLK);

  SCLK_PORT &= ~_BV(SCLK);
  if (c & _BV(3))
    SID_PORT |= _BV(SID);
  else
    SID_PORT &= ~_BV(SID);
  SCLK_PORT |= _BV(SCLK);

  SCLK_PORT &= ~_BV(SCLK);
  if (c & _BV(2))
    SID_PORT |= _BV(SID);
  else
    SID_PORT &= ~_BV(SID);
  SCLK_PORT |= _BV(SCLK);


  SCLK_PORT &= ~_BV(SCLK);
  if (c & _BV(1))
    SID_PORT |= _BV(SID);
  else
    SID_PORT &= ~_BV(SID);
  SCLK_PORT |= _BV(SCLK);

  SCLK_PORT &= ~_BV(SCLK);
  if (c & _BV(0))
    SID_PORT |= _BV(SID);
  else
    SID_PORT &= ~_BV(SID);
  SCLK_PORT |= _BV(SCLK);
*/

}
void ST7565::st7565_command(uint8_t c) {
  digitalWrite(a0, LOW);

  spiwrite(c);
}

void ST7565::st7565_data(uint8_t c) {
  digitalWrite(a0, HIGH);

  spiwrite(c);
}
void ST7565::st7565_set_brightness(uint8_t val) {
    st7565_command(CMD_SET_VOLUME_FIRST);
    st7565_command(CMD_SET_VOLUME_SECOND | (val & 0x3f));
}


void ST7565::display(void) {
  uint8_t c, p;

  for(p = 0; p < 8; p++) {
    /*
      putstring("new page! ");
      uart_putw_dec(p);
      putstring_nl("");
    */

    st7565_command(CMD_SET_PAGE | pagemap[p]);
    st7565_command(CMD_SET_COLUMN_LOWER | (0x0 & 0xf));
    st7565_command(CMD_SET_COLUMN_UPPER | ((0x0 >> 4) & 0xf));
    st7565_command(CMD_RMW);
    st7565_data(0xff);
    
    //st7565_data(0x80);
    //continue;
    
    for(c = 0; c < 128; c++) {
      //uart_putw_dec(c);
      //uart_putchar(' ');
      st7565_data(buffer[(128*p)+c]);
    }
  }
}

// clear everything
void ST7565::clear(void) {
  memset(buffer, 0, 1024);
}


// this doesnt touch the buffer, just clears the display RAM - might be handy
void ST7565::clear_display(void) {
  uint8_t p, c;
  
  for(p = 0; p < 8; p++) {
    /*
      putstring("new page! ");
      uart_putw_dec(p);
      putstring_nl("");
    */

    st7565_command(CMD_SET_PAGE | p);
    for(c = 0; c < 129; c++) {
      //uart_putw_dec(c);
      //uart_putchar(' ');
      st7565_command(CMD_SET_COLUMN_LOWER | (c & 0xf));
      st7565_command(CMD_SET_COLUMN_UPPER | ((c >> 4) & 0xf));
      st7565_data(0x0);
    }     
  }
}
