i found out how to use the ssd1306 as vector display (and thanks to the youtuber @cnlohr for the idea!):

set the frequency to maximum.
set mux to 1
draw a line in the video ram from 0,0 to 63,63

now one can set the source line and destination line to draw a single pixel:

```
static void GfxApiVectorscopeDisplay(u8 x,u8 y)
{
const u8 move_line[] = {0,
0xa8,1,0xd3,(y&63),0x40+(x&63)
};
os_i2c_write(move_line, sizeof(move_line));
}
```

when i draw fourier patterns with it it looks like this:

now i tried to draw a cube, and inserted a wait in my line function (to move the beam slower), here i draw this cube and keep increasing the delay, so the beam is slowing down:

how about battlezone?

5 Likes

acedent
(Andrew)
June 7, 2023, 1:42pm
2
Looks cool! Just wish I understood your latest experiments moreâ€¦

this is so very simple:

this is in my framebuffer:

now i set the image height (mux) to 1, i get a 128x2 image

now i move the startline, and the offset, now select one of these 64 lines containing a single pixel, use the x coordinate for this and display at y.

now you can draw lines using commands without framebuffer, by moving this single point over the screen with a bresenham:

```
void GfxApiVectorScopeLine(int x1, int y1, int x2, int y2, int speed) {
int dx = abs(x2 - x1);
int dy = abs(y2 - y1);
int sx = (x1 < x2) ? 1 : -1;
int sy = (y1 < y2) ? 1 : -1;
int err = dx - dy;
u8 br=255;
u8 sub=rand()&31;
while (1) {
GfxApiVectorscopeDisplay(x1, y1,br);
br-=sub;
if (x1 == x2 && y1 == y2) {
break;
}
int e2 = 2 * err;
if (e2 > -dy) {
err -= dy;
x1 += sx;
}
if (e2 < dx) {
err += dx;
y1 += sy;
}
}
}
```

when i switch my charge pump off before the start of a line i get a beautiful shading of the line:

```
for(;;)
{
static u16 cnt;
//cnt+=1;
if((cnt&0xff)==0)Serial.println(cnt);
u8 x=sin(counter)*28+31;
u8 y=sin(counter*1.1)*28+31;
u8 x2=sin(counter*2.2)*28+31;
u8 y2=sin(counter*2.3)*28+31;
u8 x3=sin(counter*1.5)*28+31;
u8 y3=sin(counter*1.6)*28+31;
GfxApiSetCharge(255);
GfxApiVectorScopeLine(x,y,x2,y2,cnt);
GfxApiSetCharge(0);
GfxApiVectorScopeLine(x2,y2,x3,y3,cnt);
GfxApiSetCharge(0);
GfxApiVectorScopeLine(x3,y3,x,y,cnt);
;
counter+=0.01;
adder+=0.0001;
}
}
```

fuzzing the undocumented register d1 while doing this gives intresting results:

1 Like

spacewar clockâ€¦ and the flying points are backâ€¦

1 Like

writing to register 0xd2 has huge effects! (this can be done per â€śline/pixelâ€ť)