EGG 101L INTRODUCTION TO ENGINEERING EXPERIENCE

Transcription

1 EGG 101L INTRODUCTION TO ENGINEERING EXPERIENCE LABORATORY 6: INTRODUCTION TO BREADBOARDS DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING UNIVERSITY OF NEVADA, LAS VEGAS GOAL: This section introduces breadboards and shows how they can be used in practical applications. OBJECTIVES: Understand breadboards and how they work Recreate the original LED blink exercise using a breadboard. OVERVIEW AND REQUIREMENTS: A breadboard is used to make up temporary circuits for experiments and preliminary stages of design ideas. Components are directly plugged into the board, so nothing is permanently in place and can be moved around as well as reused when necessary. The bread board has many strips of metal, usually copper, which run underneath the board connecting certain holes together and creating connective nodes. A node is a point in a circuit where two or more components are connected. The metal strips are typically laid out as shown below. DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING 1

2 These strips connect the holes on the top of the board. This makes it easy to connect components together to build circuits. To use the bread board, the legs of components are placed in the holes. The long top and bottom row of holes are usually used for power supply connections. The rest of the circuit is built by placing components and connecting them together with jumper wires. Then when a path is formed by wires and components from the positive supply node to the negative supply node, we can turn on the power and current flows through the path and the circuit comes alive. For chips with many legs (ICs), place them in the middle of the board so that half of the legs are on one side of the middle line and half are on the other side. A circuit might look like the following. COMPONENTS: Arduino Uno USB A-B Cable Breadboard Shield LED Resistor Jumper Wire Host PC Installed Arduino Uno drivers and IDE DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING 2

3 SCHEMATIC: Schematic 1 DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING 3

4 OPERATION: Connecting the LED 1. Attach the Breadboard Shield to the Arduino, making sure to properly align the pins. If you are using an R3 revision of the Arduino UNO, there will be 2 pins on each side that will have no corresponding pins on the shield. 2. Attach the Arduino UNO to the host PC with the use of the USB cable. Verify that the drivers have been properly installed. 3. Wire the circuit as shown in the schematic. Your final result should be something similar to the following snapshot. DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING 4

5 DEMO AND SCREENSHOTS: Using Danger Shield and Breadboard together: DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING 5

6 PRELAB: 1. List 2 ways of identifying which leg of a LED is the positive. 2. How do you set a pin as Input/Output? EXPERIMENTS: Experiment 1 1. Wire the Schematic1, connect LED to pin of your choice 2. Write your own code to blink the connected LED 3. Demonstrate the results to the TA Experiment 2 1. Extend the circuit and code from Experiment 1 the following way: a. Connect additional two LEDs, to the pins of your choice. Now you have three LEDs connected: LED1, LED2, and LED3. b. Modify the code, to have the following sequence: Light up LEDs in order (LED1=on,, LED2=on,, LED3=on) then turn off LEDS in order (LED3=off,, LED2=off,, LED1=off, ) Experiment 3 1. Use the circuit and code from Experiment Modify the code: a. Get the following sequence to work: LED1=on (LED2, LED3 are off) LED1=off (LED2, LED3 are off) LED2=on (LED1, LED3 are off) LED2=off (LED1, LED3 are off) LED3=on (LED1, LED2 are off) LED3=off (LED1, LED2 are off) repeat the sequence from the beginning Experiment 4 1. Use the code from Experiment Modify the code: a. Use slider1 to control the sequence speed. The same has to be used for the time where LED is on and off. As you have only ~half of the slider values available, multiply the value from the slider by 2. DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING 6

7 POSTLAB REPORT DELIVERIES Include the following elements in your postlab report: 1. Theory of operation a. Describe what the breadboard is, and why to use it. b. List 5 different components that could be placed in a breadboard. 2. Results of the experiments For each experiment, include: a. The code that you developed for the experiment. Each line that was added must be highlighted and commented with the explanation of what is its meaning. b. Brief explanation how the goal of the experiment was reached c. Screenshots of the serial monitor with the values, presenting the operation of your code 3. Answer the questions: a. What is typically found on breadboards that are missing from the breadboard shields used for this lab? b. What material is typically used to create connectivity between nodes on the breadboard? c. Why the resistor is used in series to connect LED? 4. Conclusions a. Write down your conclusions, things learned, problems encountered during the lab and how they were solved, etc. DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING 7