Download: BJT Equation Sheet

To start off the I2C master sends and 8 bit word onto the I2C bus consisting of a 7-bit address and a 1-bit read or write command for a total 8-bit word looking like <7-bit address><R/W bit> with the R/W bit being the LSB. The 7-bit address is set by the device it’s self either in it’s firmware or through switches (In some cases like the I2C line following sensor this can be change through I2C). The read or write bit lets the device that you want to communicate with know if you want to receive data from it or write data to it. This bit is set to 0 if the master wants to receive data or to 1 if it wants to send data. When a device on the I2C bus that has this address detects a packet with it’s address it will read the last bit of the word and either wait to receive more data or start sending out data at the proper time.

The problem I had with the I2C line following sensor was that Robotics Connection lists the default address of the sensor in there documentation as 0×50. What they do not mention is that this is the full 8-bit word that you must send to receive data not the 7-bit address of the device. So the actual 7-bit default address of the sensor is 0×28 (which is 0×50 shifted 1-bit to the right). This might not be an issue on other boards where you must specify the full 8-bit word when sending over I2C but in the Arduino language the Wire.requestFrom command adds the final R/W bit for you. So when i was attempting to communicate on the address 0×50 the the wire library was adding the extra bit resulting in the word being 0xA0 while when using the proper address of 0×28 results in the word being 0×50. So in the end, when using the I2C line following sensor from Robotics Connection with an Arduino based board any values in their documentation must be shifted to the right one place for it to work.

module nBitCounter(count, CLK, RST);
  parameter n = 7;

  output reg [n:0] count;
  input CLK;
  input RST;

  // Set the initial value
  initial
    count = 0;

  // Increment count on clock
  always @(posedge CLK or negedge RST)
    if (!RST)
      count = 0;
    else
      count = count + 1;

endmodule

module DualSevenSegmentDriver(ssOut, bIn, CLK);
  output [6:0] ssOut;
  input [7:0] bIn;
  input CLK;

  // Current nibble to display on LED's
  reg [3:0] dNibble;

  // Select the upper or lower nibble depending on CLK
  always @(CLK)
    dNibble = CLK?bIn[7:4]:bIn[3:0];

  // Decode nibble into LED segments
  SevenSegmentDisplayDecoder SSDD(ssOut, dNibble);
endmodule

module SevenSegmentDisplayDecoder(ssOut, nIn);
  output reg [6:0] ssOut;
  input [3:0] nIn;

  // ssOut format {g, f, e, d, c, b, a}

  always @(nIn)
    case (nIn)
      4'h0: ssOut = 7'b0111111;
      4'h1: ssOut = 7'b0000110;
      4'h2: ssOut = 7'b1011011;
      4'h3: ssOut = 7'b1001111;
      4'h4: ssOut = 7'b1100110;
      4'h5: ssOut = 7'b1101101;
      4'h6: ssOut = 7'b1111101;
      4'h7: ssOut = 7'b0000111;
      4'h8: ssOut = 7'b1111111;
      4'h9: ssOut = 7'b1100111;
      4'hA: ssOut = 7'b1110111;
      4'hB: ssOut = 7'b1111100;
      4'hC: ssOut = 7'b0111001;
      4'hD: ssOut = 7'b1011110;
      4'hE: ssOut = 7'b1111001;
      4'hF: ssOut = 7'b1110001;
    endcase
endmodule

module nBitAdder(f, cOut, a, b, cIn);
  parameter n = 7; 	

  output reg [n:0] f;
  output reg cOut;
  input [n:0] a;
  input [n:0] b;
  input cIn;

  always @(a, b, cIn)
    {cOut, f} = a + b + cIn;
endmodule

module StateMachine(Dir, Count, A, B, RST, CLK);
  output reg Dir;
  output reg Count;
  input A;
  input B;
  input RST;
  input CLK;

  reg [1:0]PS, NS;

  parameter [1:0] ST_NORM = 'b00,
                  ST_A = 'b01,
                  ST_B = 'b11,
                  ST_C = 'b10;

  initial
    begin
      PS <= ST_NORM;
      Count = 0;
    end

  always @(negedge RST or posedge CLK)
    if (!RST)
      PS <= ST_NORM;
    else if (CLK)
      PS <= NS;

  always @(A or B)
    begin
      case (PS)
        ST_NORM:
          if (A & !B)
            begin
              Dir = 0;
              Count = 1;
              NS = ST_A;
            end
          else if (!A & B)
            begin
              Dir = 1;
              Count = 1;
              NS = ST_C;
            end
          else
            NS = ST_NORM;
        ST_A:
          if (A & B)
            begin
              Dir = 0;
              Count = 0;
              NS = ST_B;
            end
          else if (!A & !B)
            begin
              Dir = 1;
              Count = 0;
              NS = ST_NORM;
            end
          else
            NS = ST_A;
        ST_B:
          if (!A & B)
            begin
              Dir = 0;
              Count = 1;
              NS = ST_C;
            end
          else if (A & !B)
            begin
              Dir = 1;
              Count = 1;
              NS = ST_A;
            end
          else
            NS = ST_B;
        ST_C:
          if (!A & !B)
            begin
              Dir = 0;
              Count = 0;
              NS = ST_NORM;
            end
          else if (A & B)
            begin
              Dir = 1;
              Count = 0;
              NS = ST_B;
            end
          else
            NS = ST_C;
      endcase
    end
endmodule

• Rip the DVD to your local computer
• Add the RiffTrax to the Video
• Burn the video to a DVD

Ripping the DVD

For ripping DVDs I find the best thing to use is VideoLan if not for it’s shear power and flexibility, then for the fact that it is free, open source, and can make a perfect rip. Once you have VideoLan installed and running you want to use the ‘Open Disc’ command to bring up the open dialog, and select the ‘DVD’ option from the ‘Disk type’ selection. Then you need to change the device name to whatever DVD drive you will be using (most of the time the default is fine). Next you need to set the ‘Title’ to the correct title for the main feature / movie that you want to rip, you might want to open the DVD using your normal DVD player to find this out, as it should be listed somewhere fairly easy to see.

Now that we have where and what on the DVD to rip we need to check the ‘Save/Stream’ option to save a copy of the DVD to the hard drive then click the ‘Settings’ button to configure a few options. Under ‘Outputs’ you will want to check ‘File’ and then click ‘Browse’ and find a good spot to save the DVD rip, be sure to give the filename a ‘.mpg’ at the end as VideoLan will not assign it a file type automatically. For ‘Encapsulation Method’ you want to select ‘MPEG PS’. Under ‘Transcoding options’ you need check off ‘Audio codec’ and select ‘mp2a’ for MPEG Layer 2 Audio compression, this will remove any proprietary encoding methods like Dolby Surround as most video editing software does not support this out of the box. Once that is done click ‘OK’ to save the settings and ‘OK’ once again to begin the ripping process, which should take 30 min. to an hour depending on the length of the movie and the speed of the DVD drive.

Adding the RiffTrax to the Movie

Over the period of re-mastering a few RiffTrax onto DVD I have used a few different NLE (Non-linear video editing) programs ranging from Adobe Premiere Elements and Adobe Premiere CS3 to Ulead Media Studio Pro, Cinelerra and Blender. Premiere Elements and Media Studio both became unstable when working with the roughly 6GB movie files. While Premiere CS3 would not open the 24P files correctly and I ended up wasting vasts amount of time trying to work around the problem and it eventually kept giving me an error when encoding so I gave up on it. As of now I am working on Sony Vegas 8.0 (Trial Version) and as of yet I have not had any problems, glitches or stability issues, though I will note this is the first RiffTrax I have done on this.

This is the hardest part of the job and thus the most difficult to explain, but I will do my best. I will explain this in the most generic terms that I can so that you can use what ever NLE program you have or chose to get. Fist you must import the DVD rip and RiffTrax audio into your editing program. <insert specifics>. Once you import them it might take a few min. to a few hours for the software to parse the files so that you can edit them, some programs like Premiere do this in the background while others like Vegas do it in the foreground.

Once the files have been imported into and processed it is now time to add them to time line and sync them up. First drag and drop the movie into the time line, be sure to check that there is a track for both the video and the audio (possibly two for the audio) otherwise the software was unable to decode one of them and you will need to double check that the software can read MPEG2 encoded files. I will say this is very unlikely since just about every NLE will support MPEG2 and it’s more likely that the audio is still in some form of surround sound.

Next you need to drag and drop the RiffTrax audio into the time line, this will be exactly the same as the video except that it will only create one new track. To sync the RiffTrax to the movie I find it’s easiest to listen to the audio to find at what time you are to pause the RiffTrax and what point in the movie you are supposed to restart it and try to sync those points as closely as possible. From there I find a point where DisembAudio speaks and then use that to sync the audio in a more precise manner, be sure to zoom in to get a more accuracy. Once you have the RiffTrax sync up the the movie be sure to save the project, and if you feel like it you can add DVD chapter marks to make browsing the DVD a little easier on you. I will usually take the time to figure out where the chapters are on the original DVD and match them as closely as possible, but that is me and if you don’t find it necessary then you can skip that part.

The last thing I do before creating the a DVD is to render a low quality version of the movie to double check that everything will line up once it is on a DVD. To do this there is usually a render or export option in the main file menu. You will want to first give it a file name in a good location and then pick encoding profile to use. The options here are limitless and the variations between programs makes it impossible to explain it in much detail. You will want to pick one that is NTSC if you are in the states or PAL for Europe, and is the same aspect ratio (widescreen vs. standard) as the original DVD. Once that is done you should look for an options or customize button and change the encoding quality to low or draft and lower the resolution down to 360 x 240 or something around that range. By doing this you will shorten the time it takes to render you draft copy as not to waste unneeded time and energy on a high quality copy.

NOTE: For Sony Vegas 8 Pro, by default it does not render with sound so you must select the ‘Customize’ button and go to the ‘Audio’ tab and check the ‘Include audio stream’ box in order to have sound.

Burning the DVD

This is probably the easiest of the three steps as most video editing programs have a built in DVD encoding and burning feature. This might be a separate bundled piece of software like Adobe Encore or Sony DVD Architect, or seamlessly integrated into the software as is the case with Adobe Premiere Elements and Ulead Media Studio Pro. Before you start there are a few settings that you want to check. First is the DVD size wither it be the 4.5 GB or 8.5 GB disks. Most movies use the 8.5 GB type, so there will be some quality loss if you choose the 4.5 GB. Also in terms of the actual DVD you are going to burn if you want to watch these on a DVD player I would suggest that you spend the extra money and get high quality DVD’s as the standard DVD’s will work but tend to skip often. If you are using software that has a built in DVD encoder find the you will want to find the burn/make DVD option (usually in the file menu), while if you are using a separate program or you just want to watch it on your computer you will want to find the export/render video option. In the case of Adobe Premiere there is an option to export directly to Encore for burning the DVD.

You will want to save the video in the MPEG-2 video format as this is what DVD’s use, so that when you burn it to the DVD you will not need to render it again. The last thing to check before burning or rendering the video is to set whatever quality settings you want, most of the programs will allow you to set a bit-rate and of course larger is better but that also means more space on the DVD so it will depend on the size you choose, also some allow you render the frame twice and merge the result for a better quality, to enable this you will want to look for a option call ‘two-pass’. Finally you will want to double check the settings that I mentioned in the previous paragraph, except that you’ll want to keep the standard DVD resolution of 720 x 480 and whatever quality you choose. Then press the Save/Render/Export/… button to create the final video.

The final step if you are using a separate program to burn the video on to a DVD is to open the respective DVD burning software and to import the video. As I mentioned before this varies greatly from program to program, but for the most part is very similar to working with the NLE. If all goes well you should not have to re-render the video to burn in on to the DVD.

NOTE: This is still a work in progress.