EEE 444 IDP2 Lab Manual PDF

Lab Manual EEE 444 Integrated Design Project II Department of Electrical and Electronic Engineering Green University of Bangladesh  Table of Contents Table of Contents............................................................

Lab Manual EEE 444 Integrated Design Project II Department of Electrical and Electronic Engineering Green University of Bangladesh  Table of Contents Table of Contents........................................................................................................................................ ii General Instructions.................................................................................................................................iii Laboratory Regulations and Safety Rules.......................................................................................... viii Experiment 1 Arduino-controlled LED Blinking and Fading Operations......................................... 9 Experiment 2 Ultrasonic Distance Measurement using Arduino..................................................... 14 Experiment 3 Real-time Motion Detection using PIR Sensor............................................................ 18 Experiment 4 Data Visualization using 16x2 LCD with Arduino..................................................... 22 Experiment 5 Digital Counter Implementation using Seven Segment Display.............................. 28 Experiment 6 Speed and Rotation Control of DC Motors using L298 Motor Driver..................... 32 Experiment 7 Input-based Servo Position Control using Arduino................................................... 40 Experiment 8 Data Entry System using 4x4 Membrane Keypad...................................................... 45 Experiment 9 Proximity Door Access Control System....................................................................... 49 Experiment 10 Implementation of an Arduino-based Calculator..................................................... 55 Department of EEE, GUB ii | P a g e  General Instructions Introduction There are 2.5 hours allocated to a laboratory session in Integrated Design Project II. It is a necessary part of the course where the attendance is compulsory. Here are some guidelines to help the students perform the experiments and submit appropriate reports. i. Students will read all the instructions carefully and carry them all out. ii. Students will ask for a demonstration if s/he is unsure of anything. iii. Student will record actual results and comment on them if the results are unexpected. iv. Students will write full and suitable conclusions for each experiment. v. If any student has any doubt about the safety of any procedure, s/he will contact the demonstrator beforehand. Arduino Uno The Arduino Uno is a versatile and widely-used microcontroller board designed around the ATmega328P microcontroller. It is an excellent choice for both beginners and experienced developers in the field of electronics and embedded systems due to its user-friendly interface and extensive community support. Key Features of Arduino Uno Microcontroller: ATmega328P Digital I/O Pins: There are 14 digital pins, 6 of which are PWM (Pulse Width Modulation) pins. These pins can generate PWM signals suitable for various control applications like motor speed control, LED fading, etc. Analog Pins: Arduino Uno has 6 analog pins. These pins are input pins and can not be used as output pins. The analog pins are used to receive analog signals from other circuitry/elements. Clock Speed: Arduino Uno has an in-build liquid crystal that generates 16 MHz clock pulse. Power Supply: There are three options to power up the Arduino Uno. The board can operate on an external supply from 6 to 20 volts. The power supply options are; o USB Port o DC Power Jack o Vin Pin ICSP Header: In-Circuit Serial Programming header enables programming the microcontroller without removing it from the board. Reset Button: The reset button, if pressed, initiates the system again from the beginning. Department of EEE, GUB iii | P a g e Arduino Usage The Arduino Uno is an open-source user-friendly platform. It provides a user the flexibility to program with great ease. Projects starting from beginner level to complex levels can be implemented using Arduino. Additionally, the Arduino developers have provided ample resources of projects and examples to guide a user to his desired project. The resources can be easily accessed at https://www.arduino.cc/. Figure 1 Arduino Uno Construction The concise board specifications are provided in Table 1. Table 1 Arduino Uno Specification Microcontroller ATmega328P Operating Voltage 5V Input Voltage (Recommended) 7 – 12 V Input Voltage (Limit) 6 – 20 V Digital I/O Pins 14 (of which 6 provide PWM output) Analog Input Pins 6 DC Current Per I/O Pin 20 mA DC Current for 3.3V Pin 50 mA Flash Memory 32 kB (ATmega328P) of which 0.5 kB used by bootloader SRAM 2 kB (ATmega328P) EEPROM 1 kB (ATmega328P) Clock Speed 16 MHz Department of EEE, GUB iv | P a g e Arduino IDE The Arduino works in synchronization with an Integrated Development Environment, called Arduino IDE. This software is well-designed to allow users program efficiently. Arduino IDE holds the capabilities of code completion, compilation, testing, and debugging. Figure 2 Arduino IDE Interface Circuit Construction Throughout these experiments we will be using Arduino Uno and basic components to construct circuits. The steps for wiring a circuit should be completed in the following order described below; 1. Turn off the power supply of Arduino before building the circuit. 2. Make sure to connect regulated supply voltage to the Vin and GND pins of the Arduino if you are not using the USB cable or DC power jack. 3. Use different grounds for Arduino Uno and the other circuitry. 4. Never detach the ATmega328P IC from the board!!! Code Uploading 1. Connect the Arduino Uno to the computer via the provided USB cable. Do not use external cables for code uploading. 2. Open Arduino IDE. Create a new sketch and save it in an appropriate folder. 3. Write down your code. Make sure the code has no typos and syntax errors. Department of EEE, GUB v|Page  4. Go to “Select Board and Port” option and select Arduino Uno as the board and select the port that has Arduino Uno written beside it. 5. Verify the code and compile. 6. Upload the code to the Arduino Uno. 7. Detach the USB cable if the Arduino is powered from external source. 8. Connect the other circuitry to the Arduino Uno. 9. Show the circuit to lab assistant/course teacher before powering on the circuit. Figure 3 Sample Construction of Arduino Circuit Common Causes of Errors While experimenting, several issues may come up. Some of the most common errors encountered during experimentation are described below; 1. Power Supply Issues: The circuit might not turn on or not working properly. There can be two possible reasons; a. Insufficient Supply: If the Arduino is not receiving enough power, the circuit might not work properly. This can happen if the power supply is weak or too many peripherals are connected. b. Incorrect Voltage: Supplying incorrect voltage to the Arduino can cause damage to the board as well as to the circuit. 2. Faulty Connections: Arduino circuits are constructed using jumper wires most often. The faulty connections can take place due to loosen wires, incorrect wiring, faulty connection leads, etc. 3. Incorrect Pin Configuration: Incorrect pin assignments in the code can lead to unexpected results. For example, setting a pin as an output when it should be an input. Again, exceeding the current limits of the pin (usually 40 mA per pin) can cause damage to the board. Department of EEE, GUB vi | P a g e  4. Defective Components: Usage of faulty peripherals might lead to malfunction of the circuits. Also, different types of shields are available to work with Arduino. Incompatible shield or modules can damage the board. 5. Software Problems: Misconfiguration of the Arduino IDE can cause errors in uploading codes to the Arduino. The possible reasons can be as follows; a. Faulty Installation: The Arduino IDE should be installed properly for proper functioning. Additionally, the software must be downloaded from the root site of Arduino (https://www.arduino.cc/en/software). The latest version of the software should be downloaded. b. Inconsistent Library: Depending on the circuit, additional library might be needed. In that case, the library should be installed to the Arduino IDE. Inconsistency in adding the library might lead to malfunctioning. c. Coding Errors: Errors in code, typos, syntax can cause errors. d. Board and Port: This is the most common error occurred during experiment. The board name and the port must be selected before uploading the code to Arduino. 6. USB Connection Issue: The code is uploaded to Arduino using USB cable. If the cable is faulty, the communication might not establish. Besides, if the drivers of the computer are not properly configured, the computer might not recognize Arduino. 7. Memory Overload: The Arduino has limited specification of its RAM and EEPROM. Overloading these can cause program to crash and behave unpredictably. Hence, proper Arduino board must be selected depending on the length and size of the program. 8. Bootloader Problem: Bootloader is the first piece of code to be loaded and run when the system initiates. It provides an interface for the user to load an operating system and applications. If the bootloader is faulty, the Arduino will not work and will not allow new sketch to upload to the board. In such cases, the bootloader should be fixed using another external Arduino or other boards. 9. Interference and Noise: Electrical noise in the empty pins or electromagnetic interference might lead to problems in circuits. Department of EEE, GUB vii | P a g e  Laboratory Regulations and Safety Rules The following regulations and safety rules must be followed in all concerned laboratory locations; 1. It is the duty of all concerned who use any electrical laboratory to take all reasonable steps to safeguard the HEALTH and SAFETY of themselves and all other users and visitors. 2. Be sure that all equipment is properly working before using them for laboratory exercises. Any defective equipment must be reported immediately to the lab instructors or lab technical staff. 3. Students are allowed to use only the equipment provided in the experiment manual. 4. Power supply terminals connected to any circuit are only energized in the presence of the instructor or laboratory staff. 5. Students should keep a safe distance from the circuit breakers, electric circuits, or any moving parts during the experiment. 6. Avoid any part of your body from being connected to the energized circuit and ground. 7. Switch off the equipment and disconnect the power supplies from the circuit before leaving the laboratory. 8. Observe cleanliness and proper laboratory housekeeping of the equipment and other related accessories. 9. Wear proper clothes and safety gloves or goggles required in working areas that involve fabrications of printed circuit boards, chemical process control systems, antenna communication equipment, and laser facility laboratories. 10. Double-check your circuit connections specifically in handling electrical power machines, AC motors, and generators before switching “ON” the power supply. 11. Make sure that the last connection to be made in your circuit is the power supply and the first thing to be disconnected is also the power supply. 12. Equipment should not be removed, or transferred to any location without permission from the laboratory staff. 13. Software installation in any computer laboratory is not allowed without permission from the laboratory staff. 14. Computer games are strictly prohibited in the computer laboratory. 15. Students are not allowed to use any equipment without proper orientation and actual hands-on equipment operation. 16. Smoking and drinking are strictly prohibited in the laboratory. 17. All these rules and regulations are necessary precautions in the Electrical Laboratory to safeguard the students, laboratory staff, the equipment, and other laboratory users. Department of EEE, GUB viii | P a g e  Experiment 1 Arduino-controlled LED Blinking and Fading Operations 1.1 Objectives 1. To familiarize with Arduino IDE 2. To understand Arduino I/O interfacing using Arduino coding 1.2 Learning Outcomes After completion of this experiment, the students will be able to 1. Have a basic understanding of the Arduino IDE and the setup procedure of Arduino Uno with the IDE 2. Understand the structure of the Arduino code 3. Know the operations of digital and analog I/O pins of Arduino and their interfacing with LEDs, resistors, and potentiometers. 4. Write codes to blink LED arrays, fade LED brightness 1.3 Theory Arduino is an open-source development board with integrated circuit components. The brain of Arduino is a microcontroller. For Arduino Uno, it is the ATmega328P microcontroller. The board provides the necessary circuit setup for the microcontroller and creates provisions for the user to access the input and output pins of the microcontroller and control them using simple codes. Arduino Uno has 14 digital pins and 6 analog pins. The simplest interfacing with these pins can be done using LEDs. LEDs are semiconductor devices that emit light upon providing appropriate voltage at their anode and cathode terminals. The anode of the LED is connected to one of the digital pins of the Arduino Uno. Depending on the state of that particular digital pin, the LED will turn on or off. The pin state, timing, and other controls are established through code uploaded to the Arduino microcontroller using Arduino IDE. The fading operation provides control over the brightness of the LED. Depending on the input voltage supplied to the LED terminals, the brightness of the LED varies. The typical output voltage of the digital pins is 5V. However, to apply a varying voltage at the LED terminal, a PWM wave is generated at the digital pins (only pins 3, 5, 6, 9, 10, 11). The duty cycle of the PWM is controlled by a potentiometer connected to one of the analog pins of the Arduino. With the varying duty cycle, the average voltage of the PWM is reduced or increased as per Equation 1.1, where 𝐷 is the duty cycle. This average voltage appears at the digital pin and in terms controls the brightness of the LED. Department of EEE, GUB 9|Page  𝑉𝑎𝑣𝑔 = 𝑉𝑚𝑎𝑥 × 𝐷 (1.1) 1.4 Required Equipment 1. Arduino Uno (1 Pcs) 2. 220Ω resistors (1 Pcs) 3. LED (1 Pcs) 4. 1 kΩ potentiometer (1 Pcs) 5. Breadboard 6. Jumper wires 1.5 Circuit Diagram Figure 1.1 LED Blinking Circuit Figure 1.2 LED Fading Circuit Department of EEE, GUB 10 | P a g e  1.6 Arduino Codes (a) Code for LED blinking const int ledPin = 11; // Define the pin where the LED is connected void setup() { pinMode(ledPin, OUTPUT); // Initialize the LED pin as an output } void loop() { digitalWrite(ledPin, HIGH); // Turn the LED on delay(1000); // Wait for 1000 milliseconds (1 second) digitalWrite(ledPin, LOW); // Turn the LED off delay(1000); // Wait for 1000 milliseconds (1 second) } (b) Code for LED fading without potentiometer int led = 11; // the PWM pin the LED is attached to int brightness = 0; // how bright the LED is int fadeAmount = 5; // how many points to fade the LED by void setup() { pinMode(led, OUTPUT); // declare pin 9 to be an output: } void loop() { analogWrite(led, brightness); // set the brightness of pin 9 // change the brightness for next time through the loop: brightness = brightness + fadeAmount; // reverse the direction of the fading at the ends of the fade: if (brightness = 255) { fadeAmount = -fadeAmount; } // wait for 30 milliseconds to see the dimming effect delay(3000); } (c) Code for LED fading using potentiometer // Define pin numbers const int ledPin = 9; // Pin connected to the LED const int potPin = A0; // Pin connected to the potentiometer Department of EEE, GUB 11 | P a g e  // Variable to hold potentiometer value int potValue = 0; // The value read from the potentiometer int ledBrightness = 0; // The brightness of the LED void setup() { pinMode(ledPin, OUTPUT); // Initialize the LED pin as an output } void loop() { // Read the potentiometer value (0 to 1023) potValue = analogRead(potPin); // Map the potentiometer value to a range suitable for PWM (0 to 255) ledBrightness = map(potValue, 0, 1023, 0, 255); // Set the LED brightness using PWM analogWrite(ledPin, ledBrightness); // Small delay to make the response smoother delay(10); } 1.7 Procedure 1. Place the LED on the breadboard. 2. Connect a 220 Ω resistor to the anode terminal of the LED (the longer lead). 3. Connect the other terminal of the resistor to the digital pin 11 of the Arduino Uno via a jumper wire. 4. Connect the cathode terminal of the LED (the shorter lead) to the ground pin of the Arduino Uno. 5. Cross-check the circuit with the one in Figure 1.1. 6. Connect the Arduino Uno to the computer using the USB cable. 7. Open the Arduino IDE and create a new sketch. Write the Code (a). 8. Select Arduino Uno as the board. 9. Save, compile, and upload the code to the Arduino Uno. Check the output. 10. Now do the same for Code (b) and check the output. 11. For the LED fading using a potentiometer, repeat steps 1-4, however, connect the LED to digital pin 9 (PWM pin) of the Arduino Uno. 12. Place a 1 kΩ potentiometer on the breadboard. Connect the first and third pins of the potentiometer to the 5V and GND pins of the Arduino Uno. 13. Connect the middle pin of the potentiometer to the A0 pin of the Arduino Uno. Cross-check the circuit with the one in Figure 1.2. 14. Upload the Code (b) to Arduino Uno and check the output for different values of the potentiometer. Department of EEE, GUB 12 | P a g e  1.8 Lab Tasks 1. Write code for an LED-chaser circuit. The number of LEDs is five. 1.9 Report Tasks 1. Write a program to blink an LED with variable delay. The delay will increase from 200 ms to 2000 ms with an increment of 200 ms. Afterwards, the delay will decrease with the same step size. 2. Write a program to blink four LEDs (Red, Green, Blue, and Yellow) sequentially. 3. Write a program to blink four LEDs (Red, Green, Blue, and Yellow). Among these, the Red and Green LEDs will fade in and fade out while the other LEDs will blink instantaneously. 1.10 Report Questions 1. What is the purpose of the digital pins on an Arduino board, and how are they typically labeled? 2. Are there any limitations or constraints to keep in mind when using analogRead() on an Arduino board? 3. What is the function of the pinMode() function in Arduino, and why is it important when working with digital pins? 4. What is the maximum and minimum voltage range for both digital and analog pins on most Arduino boards? 5. What is the difference between digital pins and analog pins on an Arduino board? Department of EEE, GUB 13 | P a g e  Experiment 2 Ultrasonic Distance Measurement using Arduino 2.1 Objectives 1. To understand the internal working principle of ultrasound sonar sensor 2. To interact with sensor modules using Arduino interfacing pins 2.2 Learning Outcomes After completion of this experiment, the students will be able to 1. Explain the principle of ultrasonic distance measurement from the concept of sound wave reflection 2. Measure the distance between a certain object and the sensor 3. Use ‘Serial Monitor’ of Arduino IDE for data visualization 2.3 Theory Ultrasonic sonar sensors, also known as ultrasonic distance sensors or ultrasonic rangefinders, are electronic devices used for measuring distances or detecting objects within a certain range. These sensors work on the principle of echolocation, similar to how bats and dolphins use sound waves to navigate and perceive their environment. The sensor includes an ultrasonic transmitter that emits high-frequency sound waves (ultrasonic waves) into the surrounding environment. These sound waves are inaudible to the human ear, typically in the ultrasonic range (around 40 kHz or higher). It also contains a receiver that is capable of detecting the reflected sound waves (echo) when they bounce off an object. The time taken for the emitted sound wave to return to the sensor is used to calculate the distance to the object. Figure 2.1 Working Principle of Sonar Sensor Department of EEE, GUB 14 | P a g e  The HC-SR04 module has 4 I/O pins. The VCC and GND pins are the power pins of the module. The TRIG pin serves as the input to the module and is connected to a digital pin of Arduino. To initiate the sensor, a calibration pulse of 10µs needs to be sent in this pin. When the TRIG pin goes LOW, 8 pulses of 40kHz emit from the transmitter, and the ECHO pin goes HIGH instantly. The pulses, getting reflected from any obstacle are detected by the receiver and the ECHO pin becomes LOW. If there is no obstacle, the ECHO pin automatically goes LOW after 38 ms. The HC-SR04 can measure up to 400 cm. The distance is measured as per Equation 2.1; where 𝑣 is the sound velocity in the medium and 𝑡 is the duration of the HIGH state of the ECHO pin. 𝑑 = 0.5 × 𝑣 × 𝑡 (2.1) 2.4 Required Equipment 1. Arduino Uno (1 Pcs) 2. HC-SR04 Sonar Sensor Module (1 Pcs) 3. 220Ω resistor (1 Pcs) 4. LED (1 Pcs) 5. Breadboard 6. Jumper wires 2.5 Circuit Diagram The TRIG and ECHO pins are connected to the digital pins 7 and 6 of Arduino Uno. An LED is connected to the digital pin 13 via a 220Ω resistor. Figure 2.2 Circuit Setup for Distance Measurement Department of EEE, GUB 15 | P a g e  2.6 Arduino Code const int Trig=7; const int Echo=6; const int LED=13; void setup() { // put your setup code here, to run once: pinMode(Trig,OUTPUT); pinMode(Echo,INPUT); pinMode(LED,OUTPUT); Serial.begin(9600); // baud rate } void loop() { // put your main code here, to run repeatedly: digitalWrite(Trig,LOW); delayMicroseconds(2); // ensures the TRIG pin is actually LOW digitalWrite(Trig,HIGH); delayMicroseconds(10); // creating the 10 microsecond pulse digitalWrite(Trig,LOW); long duration, distance; // defining variables duration=pulseIn(Echo,HIGH); distance=0.034*duration*0.5; // measuring the distance in cm unit Serial.print("Distance is: "); // accessing the serial monitor Serial.println(distance); delay(100); if(distance>10) { digitalWrite(LED,HIGH); } else { digitalWrite(LED,LOW); } } 2.7 Procedure 1. Place the sonar sensor module on the breadboard. 2. Connect the VCC, GND, TRIG, and ECHO pins of the sensor with the 5V, GND, digital pin 7, and digital pin 6 of Arduino Uno via jumper wires. Department of EEE, GUB 16 | P a g e  3. Connect an LED with the digital pin 13 through a resistor of 220Ω. 4. Cross-check the circuit with Figure 2.1 5. Open Arduino IDE and create a new sketch. 6. Write the given code in the sketch. 7. Select ‘Arduino Uno’ as the board. 8. Verify, compile, and upload the code to the Arduino. 9. Open the serial monitor in the Arduino IDE and check the distance. 10. Now place any object in front of the transmitter and check the output 11. Repeat Step 10 for different distances of the object. 2.8 Lab Tasks 1. A sonar sensor is placed at the entrance of a garage in a way that every vehicle passes the sensor while entering the garage. Modify the given code to count the number of vehicles that have entered the garage. 2.9 Report Tasks (a) Write an Arduino program to detect the distance of an object using a sonar sensor and turn on LED lights based on the following conditions; i. Distance < 5 cm: 1 red LED ii. 5 cm < Distance < 10 cm: 2 red LEDs iii. 10 cm < Distance < 20 cm: 3 red LEDs iv. A green LED to indicate the object is out of this range but in the detectable range v. A blue LED to indicate there are no detectable objects 2. A distance-averaging system has been designed using a sonar sensor. The sensor takes 20 distance values with an interval of 5s. If the average distance exceeds a certain value, the system turns on an alarm. Write the code for this system. 2.10 Report Questions 1. What is the range of values returned by the analogRead function, and how is it related to the resolution of the analog-to-digital converter (ADC) on the Arduino board? 2. How can you improve the accuracy of readings obtained with analogRead? 3. Discuss situations where you might choose to use pulseIn instead of digitalRead or analogRead for signal measurement. 4. How can you use the analogRead function to measure the voltage of a sensor that provides a voltage range beyond the Arduino's reference voltage? 5. Describe real-time constraints and considerations when using pulseIn or digitalRead in applications that require precise timing, such as robotics or motor control. Department of EEE, GUB 17 | P a g e  Experiment 3 Real-time Motion Detection using PIR Sensor 3.1 Objectives 1. To understand the internal construction and working principle of PIR motion sensor 2. To interface the PIR sensor with Arduino Uno for real-time motion sensing 3.2 Learning Outcomes After the completion of this experiment, the student will be able to 1. Explain the IR-based motion sensing principle 2. Set up a PIR sensor with Arduino Uno to control a system 3. Utilize the concept of ‘Single Trigger’ and ‘Repeating Trigger’ for toggling between different operating stages of the PIR sensor 3.3 Theory Passive Infrared Sensor is used to automate systems based on the motion sensed around them. The name suggests two key operating principles of this sensor. The term ‘Infrared’ indicates that the sensor operates utilizing the IR spectrum and the term ‘Passive’ suggests that the sensor itself does not produce any IR spectrum. The underlying theory of PIR sensors is based on the detection of changes in infrared radiation emitted by objects within the range of the sensor. Figure 3.1 Working Principle of PIR Sensor The internal construction of PIR includes two pyroelectric materials that generate a voltage signal when exposed to changes in IR radiation within its range. Objects emit IR Department of EEE, GUB 18 | P a g e  in the form of temperature. The PIR sensor detects the temperature differences between the background and the objects in motion. When an object moves, it momentarily changes the temperature of the sensor’s view which is detected as an electric signal. The signal is then further analyzed to trigger an event, in other words, it decides whether the change is significant enough. A Fresnel lens is placed above the pyroelectric materials. The lens converges the IR rays from different directions to the front face of the pyroelectric materials. Figure 3.2 PIR Sensor Pin Diagram The PIR sensor has three pins among which two are the power pins and one is the output pin, D0. Whenever the sensor detects a motion, D0 goes HIGH. There are two potentiometers for sensitivity and time delay adjustments. The sensitivity controls the detection range of the sensor (3m ~ 7m) whereas the time delay adjusts the duration of the HIGH state of the D0 pin after the detection of a movement. It ranges from 3 seconds to 5 minutes. Figure 3.3 Triggering Operation of PIR Sensor Department of EEE, GUB 19 | P a g e  The triggering modes are used to control the response type. In single triggering mode, D0 will go HIGH once it detects a motion. After the set delay time, D0 will go LOW. On the other hand, in repeated triggering mode, D0 will remain HIGH as long as the motion remains within the range. 3.4 Required Equipment 1. Arduino Uno (1 Pcs) 2. HC-SR501 PIR Sensor Module (1 Pcs) 3. LED (1 Pcs) 4. 220Ω resistor (1 Pcs) 5. Breadboard 6. Jumper wires 3.5 Circuit Diagram The D0 pin is connected to digital pin 7 of the Arduino Uno. An LED is connected to digital pin 13 through a 220Ω resistor. Figure 3.4 Circuit Setup for PIR Sensor 3.6 Arduino Codes const int pir=7; int pir_state; const int led=13; void setup() { pinMode(pir,INPUT); pinMode(led,OUTPUT); Serial.begin(9600); } void loop() {: pir_state=digitalRead(pir); if(pir_state==HIGH) Department of EEE, GUB 20 | P a g e  { digitalWrite(led,HIGH); } else { digitalWrite(led,LOW); } Serial.print("State: "); Serial.println(pir_state); delay(200); } 3.7 Procedure 1. Place the PIR sensor module on the breadboard. 2. Connect the VCC, GND, and D0 pins of the sensor with the 5V, GND, and digital pin 7 of Arduino Uno via jumper wires. 3. Connect an LED with the digital pin 13 through a resistor of 220Ω. 4. Cross-check the circuit with Figure 3.4. 5. Open Arduino IDE and create a new sketch. 6. Write the given code in the sketch. 7. Select ‘Arduino Uno’ as the board. 8. Verify, compile, and upload the code to the Arduino. 9. Move your hand across the sensor module and check the output for single trigger mode. 10. Move your hand across the sensor module and check the output for repeated trigger mode. 11. Check the serial monitor of Arduino IDE for both steps 9 and 10. 3.8 Report Tasks 1. The corridors of the annex buildings of Green University of Bangladesh have PIR- enabled lights installed. However, the range adjustment control of one of the lights is somehow damaged. Hence, sonar sensors have been used to define a perimeter around the PIR sensor. Any movement within this perimeter turns on the specific light. Design the above system and write code for it. Assume the value of the perimeter. 2. A smart parking system combines a sonar sensor and PIR sensor to effectively identify the occupancy of parking slots. LEDs are used to indicate the occupancy status. Write code for the system with your own design considerations. Department of EEE, GUB 21 | P a g e  Experiment 4 Data Visualization using 16x2 LCD with Arduino 4.1 Objectives 1. Configure 16x2 LCD to receive and display data from Arduino Uno 2. Display custom characters in LCD 4.2 Learning Outcomes After the completion of the experiment, students will be able to 1. Connect 16x2 LCD with Arduino Uno and configure different modes 2. Transmit data from Arduino Uno to LCD and perform different display operations 3. Access byte levels to display custom characters in LCD 4.3 Theory Liquid Crystal Display (LCD) is a type of flat panel display that uses liquid crystals in its primary form of operation typically found in smartphones, televisions, computer monitors, and instrument panels. A 16x2 LCD has 2 lines with 16-character box in each line. Again, each character box is made up of a 5x8 (column x row) pixel matrix. The character boxes are identified by 𝐶𝑖 𝑅𝑗 where 𝐶 represents the column and 𝑖 ranges from 0 to 15. 𝑅 refers to the row and 𝑗 ranges from 0 to 1. Figure 4.1 Pinouts and Matrix of 16x2 LCD The LCD unit has 16 pins to interface it with the Arduino Uno among which 8 pins are used for data transmission and the rest are used to configure the LCD in different modes. The detailed pin descriptions are provided in Table 4.1. Department of EEE, GUB 22 | P a g e  Table 4.1 Pin Description of 16x2 LCD Pin Pin Pin Name Pin Description Pin Connection No. 1 VSS/GND Ground Ground of MCU Supplies power to the LCD 2 VCC/VDD +5V Supply +5V of MCU Contrast Adjusts the contrast of the 3 VO Rheostat Control LCD LOW for Command Register 4 RS Register Select Digital pin of MCU HIGH for Data Register LOW for WRITE operation 5 R/W Read/Write Digital pin of MCU HIGH for READ operation Enable the READ/WRITE Digital pin of MCU 6 E Enable operation (always HIGH) 4-bit or 8-bit data transmission 7-14 D0-D7 8-bit Data Pins Digital pins of MCU between LCD and MCU 15 A Anode Power supply to the backlight +5V supply of MCU 16 C/K Cathode of the LCD Ground of MCU This experiment will utilize 4-bit data transmission and so D4-D7 will be connected to the Arduino Uno. Though 4-bit transmission mode is slower than 8-bit mode as data is transmitted nibble by nibble in a 4-bit system, it reduces the number of connections required. To display custom characters in LCD, the byte-level matrices of the LCD need to be accessed. An array referring to the custom character needs to be incorporated into the code. Figure 4.2 Byte-level Access for Custom Characters Department of EEE, GUB 23 | P a g e  4.4 Required Equipment 1. Arduino Uno (1 Pcs) 2. Hitachi HD44780 LCD/Compatible model (1 Pcs) 3. 1kΩ potentiometer (1 Pcs) 4. Breadboard 5. Jumper wires 4.5 Circuit Diagram The power pins of the LCD are connected to the power pins of the Arduino Uno. The contrast control pin of the LCD is connected to the middle pin of the potentiometer. The rest of the pins are connected as per Table 4.2. Table 4.2 Connection Details of LCD and Arduino LCD Pins Arduino Pins RS Digital pin 11 R/W GND E 10 D4-D7 Digital pins 5-2 A VCC C GND Figure 4.3 Connection Diagram of LCD and Arduino Uno Department of EEE, GUB 24 | P a g e  4.6 Arduino Codes (a) Code for displaying ASCII characters #include const int RS= 11; const int E=10; const int D4=5; const int D5=4; const int D6=3; const int D7=2; LiquidCrystal lcd(RS,E,D4,D5,D6,D7); // Creates an LCD object. Parameters: (rs, enable, d4, // d5, d6, d7) void setup() { // put your setup code here, to run once: lcd.begin(16,2); // Initializes the interface to the LCD screen, and specifies the dimensions (width and height) of the display } void loop() { // put your main code here, to run repeatedly: lcd.print("Arduino"); // Prints "Arduino" on the LCD delay(3000); lcd.setCursor(2,1); // Sets the location at which subsequent text written to the LCD will be // displayed lcd.print("LCD Tutorial"); delay(3000); // 3 seconds delay lcd.clear(); // Clears the display lcd.blink(); //Displays the blinking LCD cursor delay(4000); lcd.setCursor(7,1); delay(3000); lcd.noBlink(); // Turns off the blinking LCD cursor lcd.cursor(); // Displays an underscore (line) at the position to which the next character //will be written delay(4000); lcd.noCursor(); // Hides the LCD cursor lcd.clear(); // Clears the LCD screen } (b) Code for displaying custom characters #include // Array of bytes // B stands for binary formatter and the five numbers are the pixels Department of EEE, GUB 25 | P a g e  byte heart = {B00000, B01010,B11111, B11111, B01110, B00100, B00000, B00000}; byte smile = {B00000, B00000, B01010, B00000, B10001, B01110, B00000, B00000}; byte lock = {B01110, B10001, B10001, B11111, B11011, B11011, B11111, B00000}; byte character = {B11111, B10101, B11111, B01010, B01110, B11111, B01110, B01110}; const int RS= 11; const int E=10; const int D4=5; const int D5=4; const int D6=3; const int D7=2; // Creates an LCD object. Parameters: (rs, enable, d4, d5, d6, d7) LiquidCrystal lcd(RS,E,D4,D5,D6,D7); void setup() { // Initializes the interface to the LCD screen, and specifies the dimensions of the display lcd.begin(16,2); lcd.createChar(0, heart); // Create a custom character lcd.createChar(1, smile); lcd.createChar(2, lock); lcd.createChar(3, character); // Clears the LCD screen lcd.clear(); // Print a message to the LCD lcd.print("Custom Character"); } void loop() { // put your main code here, to run repeatedly: lcd.setCursor(1, 1); lcd.write(byte(0)); // Display the custom character 0, the heart lcd.setCursor(5, 1); lcd.write(byte(1)); lcd.setCursor(9, 1); lcd.write(byte(2)); lcd.setCursor(13, 1); lcd.write(byte(3)); } Department of EEE, GUB 26 | P a g e  4.7 Procedure 1. Place the LCD on the breadboard and connect it to the Arduino Uno and potentiometer as per Table 4.2. Cross-check the circuit with the one in Figure 4.3. 2. Adjust the contrast of the LCD by rotating the potentiometer knob. 3. Open a new sketch in Arduino IDE and write Code (a). 4. Verify, compile, and upload the code to the Arduino. 5. Power up the circuit and observe the output. 6. Open another new sketch in Arduino IDE and write Code (b). 7. Repeat steps 4 and 5. 4.8 Lab Tasks 1. Write code for the custom character provided by the course instructor during the lecture. 4.9 Report Tasks 1. Write a code to display the analog data taken from a potentiometer connected to the Arduino. 2. Write a code to turn on/off an LED using a pushbutton. The status of the LED will be displayed on the LCD. 3. Write a code to display the data obtained from the sonar sensor. 4. Write a code that will display “GUB EEE Green” in the middle of the first row of a 16x2 LCD. In the second row, there will be scrolling text from right to left. The text should be “Your nickname–IDP2”. 4.10 Report Questions 1. What are the advantages of using I2C or SPI communication protocols for connecting an LCD to an Arduino and when might you prefer one over another? 2. What is the purpose of a potentiometer in an LCD setup with Arduino, and how is it used for fine-tuning the display? 3. What is the difference between a 16x2 and a 20x4 LCD, and how might your Arduino code need to change when switching between these two types? 4. Make a discussion on the usage of I2C to reduce the number of I/O pins of LCD. Provide appropriate code snippets to validate your discussion. Department of EEE, GUB 27 | P a g e  Experiment 5 Digital Counter Implementation using Seven Segment Display 5.1 Objectives 1. To interface a segment display with Arduino Uno without any driver circuit 2. To display numbers on the seven-segment display 5.2 Learning Outcomes After completion of this experiment, the students will be able to 1. Connect seven-segment displays with Arduino Uno 2. Control the LEDs of the display using codes 5.3 Theory A seven-segment display is commonly used for displaying numeric data in devices like digital clocks and calculators. It has seven individual LEDs (labeled ‘a’ to ‘g’ in Figure 5.1) along with a dot LED, ‘dp’. The LEDs can be accessed through individual pins. By controlling the voltage states at these pins, numbers 0 to 9 can be displayed. Additionally, some alphabets can be displayed. Depending on the shorted terminals of the LEDs, two types of displays are available; a. Common Cathode (CC): Here all the cathode terminals of the LEDs are shorted and only one pin is available. b. Common Anode (CA): Here all the anode terminals of the LEDs are shorted and only one pin is available. Figure 5.1 Seven Segment Display Variants (CA and CC) Department of EEE, GUB 28 | P a g e  5.4 Required Equipment 1. Arduino Uno (1 Pcs) 2. Seven Segment Display (CA) (1 Pcs) 3. 220Ω resistors (7 Pcs) 4. Breadboards 5. Jumper wires 5.5 Circuit Diagram A common anode seven-segment display is connected to the Arduino through 220Ω resistors. The ‘dp’ is not connected. Figure 5.2 Digital Counter Setup 5.6 Arduino Codes // Pin connections for 7-segment display int segA = 6; int segB = 7; int segC = 8; int segD = 2; int segE = 3; int segF = 5; int segG = 4; Department of EEE, GUB 29 | P a g e  int digits = { {LOW, LOW, LOW, LOW, LOW, LOW, HIGH}, // 0 {HIGH, LOW, LOW, HIGH, HIGH, HIGH, HIGH}, // 1 {LOW, LOW, HIGH, LOW, LOW, HIGH, LOW}, // 2 {LOW, LOW, LOW, LOW, HIGH, HIGH, LOW}, // 3 {HIGH, LOW, LOW, HIGH, HIGH, LOW, LOW}, // 4 {LOW, HIGH, LOW, LOW, HIGH, LOW, LOW}, // 5 {LOW, HIGH, LOW, LOW, LOW, LOW, LOW}, // 6 {LOW, LOW, LOW, HIGH, HIGH, HIGH, HIGH}, // 7 {LOW, LOW, LOW, LOW, LOW, LOW, LOW}, // 8 {LOW, LOW, LOW, LOW, HIGH, LOW, LOW} // 9 }; void setup() { // Set all pins for the 7-segment display as output pinMode(segA, OUTPUT); pinMode(segB, OUTPUT); pinMode(segC, OUTPUT); pinMode(segD, OUTPUT); pinMode(segE, OUTPUT); pinMode(segF, OUTPUT); pinMode(segG, OUTPUT); } void loop() { for (int i = 0; i