FM VERİCİ

Bu aralar üzerinde çalıştığım bir rf projesi için teknik bilgiler ararken UDEA tarafından hazırlanmış türkçe dokümanlara ulaştım. İlk dokümanda bir rf modülün uygulamada nasıl kullanılması gerektiği en ince noktalara kadar anlatılmış. Sizlerinde rf uygulamalarınızda pcb konusunda işinize yarayacaktır. Anten uygulamaları ile ilgili olarakta diğer dokümanda oldukça faydalı olacak bilgiler var.

Instead of drawing only the edges of a polyhedron, this time we draw the faces and 'fill' it with corresponding colors. This demo now uses a dsPIC (16-bit and 40MIPS core) for "faster" and "smoother" graphics in the N6610/N6100 LCD (w/ pcf8833 controller). See "lcd6610.h" for the used pinouts.








There are several ways of "hidden surface removal". The easiest way, and most appropriate for drawing convex polyhedron is the use of Backface culling. "Backface" will determine whether a surface (e.g. triangular face) is need to be drawn or not.

/-----------------------------------------------------------------------------------/

Draw3D routine:

/***** Draw 3D object with given vertices, triangular faces and angles of rotation******/<br />void draw_3D(Vertex * V, Triangle * T, nVertices, nTriangles, R)<br />{<br /> // sin and cos values<br /> sinX = sin_table( R.x ) / 255.0;<br /> sinY = sin_table( R.y ) / 255.0;<br /> sinZ = sin_table( R.z ) / 255.0;<br /><br /> cosX = cos_table( R.x ) / 255.0;<br /> cosY = cos_table( R.y ) / 255.0;<br /> cosZ = cos_table( R.z ) / 255.0;<br /><br /> // calculate the new coordinates of points<br /> for (i=0; i< nVertices; i++)<br /> {<br /> tempX = V[i].x;<br /> tempY = V[i].y;<br /> tempZ = V[i].z;<br /><br /> // store previous coordinates<br /> old_points[i] = new_points[i];<br /><br /> // rotation on X axis<br /> py = tempY * cosX - tempZ * sinX;<br /> pz = tempY * sinX + tempZ * cosX;<br /> tempY =py; tempZ = pz;<br /><br /> // rotation on Z axis<br /> px = tempX * cosZ - tempY * sinZ;<br /> py = tempX * sinZ + tempY * cosZ;<br /> tempX = px; tempY = py;<br /><br /> // rotation on Y axis<br /> px = tempX * cosY - tempZ * sinY;<br /> pz = tempX * sinY + tempZ * cosY;<br /><br /> // save the screen coordinates<br /> new_points[i].x = px * SCALE_FACTOR + OFFSETX;<br /> new_points[i].y = py * SCALE_FACTOR + OFFSETY;<br /> }<br /> // erase previous triangles<br /> for (i=0; i< nTriangles; i++)<br /> {<br /> if( !Backface( old_points[T[i].A], old_points[T[i].B], old_points[T[i].C] ) )<br /> fill_triangle(old_points[T[i].A], old_points[T[i].B], old_points[T[i].C], BG_COLOR);<br /> }<br /> // lcd plot new triangles<br /> for (i=0; i< nTriangles; i++)<br /> {<br /> if( !Backface( new_points[T[i].A], new_points[T[i].B], new_points[T[i].C] ) )<br /> fill_triangle(new_points[T[i].A], new_points[T[i].B], new_points[T[i].C], T[i].color);<br /> }<br />}<br />





triangle color-fill routine:


void fill_triangle(Point A, Point B, Point C, color)<br />{ <br /> // bubble sort points<br /> if(B.y< A.y){ P=A; A=B; B=P; }<br /> if(C.y< B.y){ P=B; B=C; C=P; }<br /> if(C.y< A.y){ P=A; A=C; C=P; }<br /> if(B.y< A.y){ P=A; A=B; B=P; }<br /><br /> // compute dx's<br /> dx1=0, dx2=0, dx3=0;<br /> if (B.y-A.y > 0) dx1 = (float)(B.x-A.x)/(B.y-A.y);<br /> if (C.y-B.y > 0) dx2 = (float)(C.x-B.x)/(C.y-B.y);<br /> if (C.y-A.y > 0) dx3 = (float)(C.x-A.x)/(C.y-A.y);<br /><br /> for(h = (i16) A.y; h < B.y; h++) {<br /> sx = A.x + ((h - A.y) * dx3);<br /> ex = A.x + ((h - A.y) * dx1);<br /> draw_hline(sx,ex,h,color);<br /> }<br /> for(h = (i16) B.y; h < C.y; h++) {<br /> sx = A.x + ((h - A.y) * dx3);<br /> ex = B.x + ((h - B.y) * dx2);<br /> draw_hline(sx,ex,h,color);<br /> }<br />}<br />

(*another version of using dsPIC hardware multiplier/divider is included in the download)




detect whether a triangle is facing backward.
/***** BACKFACE CULLING ******/<br />BOOL Backface(Point A, Point B, Point C)<br />{<br /> Point L1, L2; // lines/edges<br /><br /> L1.x = A.x - B.x;<br /> L1.y = A.y - B.y;<br /> L2.x = C.x - B.x;<br /> L2.y = C.y - B.y;<br /><br /> if( ((L1.x * L2.y) - (L1.y * L2.x)) < 0 )<br /> return TRUE;<br /> return FALSE;<br />}<br />






Complete MPLAB+C30 project (dsPIC33FJ16GS504):

n6610lcd_3D_demo_part2.zip

Nokia 6610/6100 LCD 3D projections demo using Microchip's PIC18F25J11.
PIC18F25J11 is clocked at 12MHz external oscillator with 4xPLL enabled.
It's operated at 3.3V supply, same with the LCD (and so, direct connections and higher spi clock rates are possible).





The demo is all about simple 3D projection - no rendering, no raycasting, etc., just the plotting of edges/lines. It displays common polyhedrons like tetrahedron, hexahedron(cube), octahedron, square pyramid, and triangular prism.




"3Ddemo.c"


/***** Draw 3D object with given vertices, edges and angles of rotation******/<br />void draw_3D(Vertex * V, Edge * E, nVertices, nEdges, xRot, yRot, zRot)<br />{<br /> u8 i;<br /> float tempX,tempY,tempZ; // temporary coordinates<br /> float sinX,sinY,sinZ,cosX,cosY,cosZ; // precomputed sin and cos values<br /> float px,py,pz; // projected<br /><br /> // sin and cos values<br /> sinX = sin_table( xRot ) / 255.0;<br /> sinY = sin_table( yRot ) / 255.0;<br /> sinZ = sin_table( zRot ) / 255.0;<br /><br /> cosX = cos_table( xRot ) / 255.0;<br /> cosY = cos_table( yRot ) / 255.0;<br /> cosZ = cos_table( zRot ) / 255.0;<br /><br /> // calculate the new coordinates of points<br /> for (i=0; i< nVertices; i++)<br /> {<br /> tempX = V[i].x;<br /> tempY = V[i].y;<br /> tempZ = V[i].z;<br /><br /> // store previous coordinates<br /> old_points[i] = new_points[i];<br /><br /> // rotation on X axis<br /> py = tempY * cosX - tempZ * sinX;<br /> pz = tempY * sinX + tempZ * cosX;<br /> tempY =py; tempZ = pz;<br /><br /> // rotation on Z axis<br /> px = tempX * cosZ - tempY * sinZ;<br /> py = tempX * sinZ + tempY * cosZ;<br /> tempX = px; tempY = py;<br /><br /> // rotation on Y axis<br /> px = tempX * cosY - tempZ * sinY;<br /> pz = tempX * sinY + tempZ * cosY;<br /><br /> // save the screen coordinates<br /> new_points[i].x = (u8)px * SCALE_FACTOR + OFFSETX;<br /> new_points[i].y = (u8)py * SCALE_FACTOR + OFFSETY;<br /> }<br /><br /> // lcd plot<br /> for (i=0; i< nEdges; i++)<br /> {<br /> // erase old edges<br /> drawline(<br /> old_points[E[i].start].x, old_points[E[i].start].y,<br /> old_points[E[i].end].x, old_points[E[i].end].y,<br /> BG_COLOR);<br /> // draw new edges<br /> drawline(<br /> new_points[E[i].start].x, new_points[E[i].start].y,<br /> new_points[E[i].end].x, new_points[E[i].end].y,<br /> LINE_COLOR);<br /><br /> }<br />


*based on original sources:

Nokia 6100 LCD with CCS C


3D Vector objects in C using the PIC micro



Microchip C18 project:  n6610lcd_3D_demo.zip