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.


1.3 Running LEDs

Figure 3. Code for the running LEDs


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.


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.



2.3 Push to blink the LED

             Figure 6. Code for push to blink LED


2.4 Push to change blink speed

                Figure 7. Modified code to implement given function.


                    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


To be continued...
    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.