This is the code of the Library:
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static void updateBoundingBox(uint8_t xmin, uint8_t ymin, uint8_t xmax, uint8_t ymax) {
#ifdef enablePartialUpdate
if (xmin < xUpdateMin) xUpdateMin = xmin;
if (xmax > xUpdateMax) xUpdateMax = xmax;
if (ymin < yUpdateMin) yUpdateMin = ymin;
if (ymax > yUpdateMax) yUpdateMax = ymax;
#endif
}
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)) {
my_setpixel(x+i, y+j, color);
}
}
}
updateBoundingBox(x, y, x+w, y+h);
}
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::drawstring_P(uint8_t x, uint8_t line, const char *str) {
while (1) {
char c = pgm_read_byte(str++);
if (! c)
return;
drawchar(x, line, 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++ ) {
st7565_buffer[x + (line*128) ] = pgm_read_byte(font+(c*5)+i);
x++;
}
updateBoundingBox(x, line*8, x+5, line*8 + 8);
}
// 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);
}
// much faster to put the test here, since we've already sorted the points
updateBoundingBox(x0, y0, x1, 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) {
my_setpixel(y0, x0, color);
} else {
my_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++) {
my_setpixel(i, j, color);
}
}
updateBoundingBox(x, y, x+w, y+h);
}
// 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++) {
my_setpixel(i, y, color);
my_setpixel(i, y+h-1, color);
}
for (uint8_t i=y; i<y+h; i++) {
my_setpixel(x, i, color);
my_setpixel(x+w-1, i, color);
}
updateBoundingBox(x, y, x+w, y+h);
}
// draw a circle outline
void ST7565::drawcircle(uint8_t x0, uint8_t y0, uint8_t r,
uint8_t color) {
updateBoundingBox(x0-r, y0-r, x0+r, y0+r);
int8_t f = 1 - r;
int8_t ddF_x = 1;
int8_t ddF_y = -2 * r;
int8_t x = 0;
int8_t y = r;
my_setpixel(x0, y0+r, color);
my_setpixel(x0, y0-r, color);
my_setpixel(x0+r, y0, color);
my_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;
my_setpixel(x0 + x, y0 + y, color);
my_setpixel(x0 - x, y0 + y, color);
my_setpixel(x0 + x, y0 - y, color);
my_setpixel(x0 - x, y0 - y, color);
my_setpixel(x0 + y, y0 + x, color);
my_setpixel(x0 - y, y0 + x, color);
my_setpixel(x0 + y, y0 - x, color);
my_setpixel(x0 - y, y0 - x, color);
}
}
void ST7565::fillcircle(uint8_t x0, uint8_t y0, uint8_t r,
uint8_t color) {
updateBoundingBox(x0-r, y0-r, x0+r, y0+r);
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++) {
my_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++) {
my_setpixel(x0+x, i, color);
my_setpixel(x0-x, i, color);
}
for (uint8_t i=y0-x; i<=y0+x; i++) {
my_setpixel(x0+y, i, color);
my_setpixel(x0-y, i, color);
}
}
}
void ST7565::my_setpixel(uint8_t x, uint8_t y, uint8_t color) {
if ((x >= LCDWIDTH) || (y >= LCDHEIGHT))
return;
// x is which column
if (color)
st7565_buffer[x+ (y/8)*128] |= _BV(7-(y%8));
else
st7565_buffer[x+ (y/8)*128] &= ~_BV(7-(y%8));
}
// 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)
st7565_buffer[x+ (y/8)*128] |= _BV(7-(y%8));
else
st7565_buffer[x+ (y/8)*128] &= ~_BV(7-(y%8));
updateBoundingBox(x,y,x,y);
}
// the most basic function, get a single pixel
uint8_t ST7565::getpixel(uint8_t x, uint8_t y) {
if ((x >= LCDWIDTH) || (y >= LCDHEIGHT))
return 0;
return (st7565_buffer[x+ (y/8)*128] >> (7-(y%8))) & 0x1;
}
void ST7565::begin(uint8_t contrast) {
st7565_init();
st7565_command(CMD_DISPLAY_ON);
st7565_command(CMD_SET_ALLPTS_NORMAL);
st7565_set_brightness(contrast);
}
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
// set up a bounding box for screen updates
updateBoundingBox(0, 0, LCDWIDTH-1, LCDHEIGHT-1);
}
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