CE351 Lab 3 2020 Fall
LEDs and SSDs
Name: Audra Benally
Email: albenally1@fortlewis.edu


1. Introduction

       In this lab, LEDs are connected and programmed to blink. The speed of the blinks are controlled with the code and with the implementation of a push button. A seven segment display is also hooked up and controlled both manually and with code. The seven segment display is wired in various ways using first 7 wires, then 3 wires using a decoder, then 1 wire using a shift-register.

2. The Code and the Results

                    LED portion:

1.1 Blink the on-board LED:

   
             Figure 1: Code to blink the on-board LED.

1.2 Blink an external LED:

     
             Figure 2: Code to blink an external LED.

             Video:
   


1.3 Running LEDs

   
             Figure 3. Code for the running LEDs

             Video:
   


2.1 Push button to turn on, release to turn off

   
             Figure 4. Code for push button to turn off led when button is pushed.

             Video:
   


2.2 Push button to turn off, release to turn on

   
                Figure 5. Code for push button, with HIGH and LOW changed so the opposite of 2.1 will occur.

             Video:
   


2.3 Push to blink the LED

   
             Figure 6. Code for push to blink LED

             Video:
   


2.4 Push to change blink speed

   
                Figure 7. Modified code to implement given function.

             Video:
   


                    SSD portion:

2.1 SSDs powered by 7 individual wires

   
                Figure 8. Different number displays using seven separate wires. I believe I fried the e LED while playing with the different wires. I'm not sure how, but the e is shown to be out on the right with the "0" display. Because of this, I could only display certain numbers.


2.1 SSDs powered by 3 wires (manually)

   
                Figure 9. Circuit using a decoder and three wires to control SSD.

   
             Figure 10. All numbers displayed. Because the e LED is out, the A (blue), B (green), C (red), and D (yellow) wires are shown with each number.

2.1 SSDs powered by single wire

   
                Figure 11. Shift Register test circuit with 8 LEDs

                Video:
   

To be continued...
Discussion
    This was a very enjoyable. The leds are fun to set up and the way the SSD works is fascinating. I appreciate the way the SSD lab is set up: going from manually connecting each segment LED to having a shift register chip to be able to control the entire thing. It is interesting how logic and code slowly gets integrated into making a more efficient seven segment display. I plan to continue with this lab until it is completed because I really want to learn how to set these SSDs up.