4.2.2 Exporting Virtual Appliance Files.4.2 Using Installation Media or Disk Image (.iso).2 Considerations When Using Virtual Machines.Tape one or two of these onto the motor such that it aligns with (and protects) the phototransistors. To do this cutout a rectangular piece of cardboard with an intern cutout that is about the size of the phototransistor array. This keeps stray light from bouncing into the sensor and lighting up the 7-seg accidentally. Now we want to add some shielding to the phototransistors. Once you get them lined up, secure the breadboard to the base. Next you want to put the breadboard and phototransistor array underneath the disk such that the phototransistors line up with the lines/rows of the disk. The bolt goes through the paper and screws into the motor shaft. Put the disk on the motor and secure it with the bolt. Cutout the circle part and punch a small hole in the center of the disk. Then print out the attached picture of the disk. I used an acrylic sheet that I had lying around. Take your electronics and place it on the base of your choice. Here is a demo model I made for the electronics: If some parts of the 7-seg are not lighting up then the corresponding phototransistor might be broken or be plugged in wrong. If none of the 7-seg lights up then you want to unplug the battery as there is probably a short. Connect the positive wire to the potentiometer's wiper pin of the potentiometer (this is often the middle pin but check the datasheet). Then connect the motor's negative wire to ground. Connect one lead to the ground rail and one to the positive rail (9V in this case). Plug in the potentiometer below the 7-seg. Plug in the 7-seg display further down the breadboard.Ĭonnect the phototransistors to the 7-seg using the following picture as a guide Make sure the leads of the resistors don't short anything! The other end should go into the ground rail. One end should go in the same column as the short lead of the phototransistor. Put the next phototransistor 3 spots down, there should be two columns in-between every phototransistor. The short end should go into column 57, row a, b, c, d, or e. The long lead should go into the positive rail. If you are interested in learning more, take a further look into transistors: This is important in making the sensor act like a switch. What are the resistors for? Why not only use the phototransistors? The resistors are necessary to control the current through the phototransistor. This is what controls the rate of rotation of the disk, which in turn controls how fast your message scrolls on the 7-seg. The simulation also shows a motor with the speed controlled by a potentiometer. When you slide the dial to the right you will notice the corresponding part of the 7-seg light up. It simulates what happens when there is a cutout in the disk. Click one of the phototransistors and slide the dial. The simulation below shows the phototransistor array. Cutout red and blue and the middle and bottom right section of the 7-seg will light up.

If you cutout the purple part of the slice then the top element in the 7-seg will be illuminated. If you cutout every color in one slice then the entire 7-seg will light up for the duration of that slice. The second picture shows the disk with each color corresponding to a part of the 7-seg. If there is a cutout and light is shining through, then current will be allowed to flow through the transistor and will illuminate the section of the 7-seg. 8 phototransistor sensors below the disk will sense the light being either blocked or allowed through. The disk is rotated using a motor so that each slice gets a turn controlling the 7-seg. The cutouts in each slice will light up an individual section of the 7-seg. The disk will be like a pizza with 28 slices, each having 8 cutouts. So how does all of this relate to our device? We will use cutouts instead of pits to allow light to pass through to sensors beneath the disk.

Make virtual optical disk file