I wanted to get started with FPGAs for a long time.  Today, it finally happened.  I bought a #TinyFPGA A-Series (A1 specifically) on Tindie, and started coding.  After a few hours, I came up with a bouncing ball on a VGA monitor (starting from scratch).

I know there are simple VGA examples out there, but I resisted looking at them for the exercise. It's not super-complex, but a lot of things have to be right to get this to work.  There are a few issues, mainly about the clock.  I used the internal clock source on the FPGA, which isn't very accurate or stable.  Additionally, the closest I could get to the proper 25.175 MHz dot clock was 24.18 MHz.  The result is a little jitter on the display. I could solve this with an external oscillator, but this was just an exercise.

The hardware is simply the A1 board and six resistors to shift the RGB levels and provide a proper 75-ohm output impedance.  I didn't have any VGA connectors around, so I used BNC's and an old-school VGA-to-BNC cable.  There are a few in-progress projects in the picture, but you can locate the TinyFPGA and the BNCs.  The three LEDs from the example in the TinyFPGA documentation are still in the breadboard :-)

The verilog code could probably be prettied up a lot, but at this point, I'm just excited to have something going.  This is sure to give experienced RTL jockeys a good laugh:

module TinyFPGA_A1 (
  output pin4_mosi,
  output pin5,
  output pin6,
  output pin7_done,
  output pin8_pgmn
                    );
  
  wire clk;
   OSCH #(.NOM_FREQ("24.18") // should be 25.175 - close enough!
          ) internal_oscillator_inst (
                                      .STDBY(1'b0), 
                                      .OSC(clk)
                                      );
   
   parameter ball_size = 20;
   reg [9:0] horiz_ctr;
   reg       hsync;
   reg [9:0] vert_ctr;
   reg       vsync;
   reg       hblank;
   reg       vblank;
   reg [9:0] row;
   reg [9:0] col;
   reg       dr;
   reg       dc;
   reg [2:0] rgb;
   always @(posedge clk) begin
      horiz_ctr <= horiz_ctr + 1; 
      if (((vert_ctr-45) >= row) &&
          ((vert_ctr-45) <= (row+ball_size)) &&
          ((horiz_ctr-160) >= col) &&
          ((horiz_ctr-160) <= (col+ball_size)))
        rgb = 3'b100;
      else
        rgb = 3'b001;
     
      case (horiz_ctr)
        10'd16:  hsync <= 1;
        10'd112: hsync <= 0;
        10'd160: hblank <= 0;
        10'd800:
          begin
             horiz_ctr <= 0;
             hblank <= 1;
             vert_ctr <= vert_ctr + 1;
             case (vert_ctr)
               10'd10:  vsync <= 1;
               10'd12:  vsync <= 0;
               10'd45:  vblank <= 0;
               10'd525:
                 begin
                    vert_ctr <= 0;
                    vblank <= 1;
                    if (dr)
                      row <= row + 1;
                    else
                      row <= row - 1;
                    if (dc)
                      col <= col + 1;
                    else
                      col <= col - 1;
                    if (row < 1) begin
                       row <= 1;
                       dr <= ~dr;
                    end
                    if (col < 1) begin
                       col <= 1;
                       dc <= ~dc;
                    end
                    if (row > (479-ball_size)) begin
                       row <= 479-ball_size;
                       dr <= ~dr;
                    end                               
                    if (col > (639-ball_size)) begin
                       col <= 639-ball_size;
                       dc <= ~dc;
                    end           
                 end
             endcase
          end
      endcase
   end

   wire frame_active = !vblank & !hblank;

   assign pin8_pgmn = !hsync;
   assign pin7_done = !vsync;
   assign pin4_mosi = frame_active & rgb[0];
   assign pin5 = frame_active & rgb[1];
   assign pin6 = frame_active & rgb[2];      
endmodule

If I'm reading the output of the Lattice Diamond software correctly (doubtful), I've used 117 of the 256 available LUT's - less than half.  I didn't think about optimizing the code at all - at this point, I wouldn't know exactly where to start.

I am really impressed with how easy this all is. Kudos to @Luke Valenty  on a very nice project/product.