void ssd1306_drawLine(SSD1306 *p, int x0, int y0, int x1, int y1, int color)
{
/*
* bresenham's algorithm - thx wikpedia
* taken from Adafruit gfx library
*/
int16_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);
}
int16_t dx, dy;
dx = x1 - x0;
dy = abs(y1 - y0);
int16_t err = dx / 2;
int16_t ystep;
if (y0 < y1)
{
ystep = 1;
}
else
{
ystep = -1;
}
for (; x0 <= x1; x0++)
{
if (steep)
{
ssd1306_setPixel(p, y0, x0, color);
}
else
{
ssd1306_setPixel(p, x0, y0, color);
}
err -= dy;
if (err < 0)
{
y0 += ystep;
err += dx;
}
}
}
int
main(int argc, char * argv[])
{
printf("Starting SSD1306 Test\n");
int spiChannel = 0;
int resetPin = 17;
int dcPin = 21;
printf("Using SPI Channel %d\n", spiChannel);
printf("Reset Pin = %d, DC Pin = %d\n", resetPin, dcPin);
/*
* 10 MHz did work on a breadboard
* safer to use slower speeds probably
* 200 kHz is the approximate minimum
* otherwise not all data will be transmitted
*/
int clock = 200000;
SSD1306 * disp = ssd1306_create(spiChannel, resetPin, dcPin, clock);
printf("Init\n");
ssd1306_init(disp, SSD1306_ROWS_64, SSD1306_VCCSATE_SWITCHCAP);
int y = 0;
int x = 0;
for (; x < 100; x += 1) {
for (y = 0; y < 10; ++y) {
ssd1306_setPixel(disp, x, y, 1);
}
}
for (x = 0; x < 100; x += 10) {
for (y = 0; y < 10; ++y) {
ssd1306_setPixel(disp, x, y, 0);
}
}
printf("Display 10 white Boxes\n");
ssd1306_display(disp);
ssd1306_delay(1000);
printf("Clear\n");
ssd1306_clear(disp, 0);
printf("Draw Lines\n");
int i;
for (i=0; i < 128; i+=4) {
ssd1306_drawLine(disp, 0, 0, i, 64-1, 1);
ssd1306_display(disp);
}
for (i=0; i < 64; i+=4) {
ssd1306_drawLine(disp, 0, 0, 128-1, i, 1);
ssd1306_display(disp);
}
printf("Start Scrool Right\n");
ssd1306_startScrollRight(disp, 0x00, 0x0F);
ssd1306_delay(2000);
ssd1306_stopScroll(disp);
ssd1306_delay(1000);
printf("Start Scrool Left\n");
ssd1306_startScrollLeft(disp, 0x00, 0x0F);
ssd1306_delay(2000);
ssd1306_stopScroll(disp);
ssd1306_delay(1000);
ssd1306_destroy(disp);
return 0;
}
