Now, that you have connected all segments to the cathode and everything is working properly you are already to show off to your friends. Look back at ...
The Date of Birth Project is a breadboard circuit that displays a person's day of birth (in this case 07/21/1996). Design Specifications: 1.) must be common cathode 2.) 150 ohms-270 ohms 3.) K-mapping 4.) 2 chips must be NAND 5.) 2 chips must be NOR
To begin this project you need to understand exactly what you are getting yourself into: A seven segment display is similar to a scoreboard you find at a basketball game. Each segment acts on its own depending on the word. So, this project has three switches so each switch can go off or on. Where a switch is off or on changes the number on the seven segment display. This is a quick foreshadowing of all the steps that will be forthcoming. First, you create a chart that will show a number on each line of your truth table (truth table is shown in the picture). Also, I've included all the supplies needed for this epic adventure.
Step 2: K-Mapping
After you finish your truth table, you are now ready to develop a word for each segment. To find your word, you use a method called K-mapping; K-mapping is a quick and easy process to find groups when the switch is on (creating a word). The picture has a couple examples of when a segment is on, the group is created, and the what word is implemented.
Step 3: Developing the Circuits
After you have all your words for each segment, you are ready to develop the circuits. Picking the type of circuit is simple, draw a circuit for AOI, NAND, and NOR then choose the circuit that has the least amount of chips (less chips= more space on breadboard). Repeat this step for all segments. For this birthday there are 12 chips including R-Pack, 1 inverter, 2 AND, 2 OR, 2 NAND, and 4 NOR.