Arduino is an open-source electronic tool that uses a combination of hardware and software. The Arduino board can perform the required functions by sending instructions from the microcontroller on the board. This can be achieved by using the Arduino programming language and the Arduino software (IDE).

Arduino finds application in everyday objects to complex scientific instruments. Arduino was designed by Ivrea Interaction Design Institute as an easy tool for fast prototyping, aimed at students without a background in electronics and programming.

Advantages of using Arduino

Arduino is a key tool to learn new things. Anyone – children, hobbyists, artists, programmers – can start tinkering just by following the step by step instructions of a kit, or sharing ideas online with other members of the Arduino community. Several other advantages of Arduino are:

• Inexpensive: Arduino boards are relatively inexpensive.
• Cross-platform: The Arduino Software (IDE) runs on Windows, Macintosh OSX, and Linux operating systems.
• Simple, clear programming environment: The Arduino IDE is easy to use for beginners and it is very flexible.
• Open source and extensible software: Arduino software is an open-source tool and can be extended by users.
• Open source and extensible hardware: Arduino board pins are published and experienced circuit designers can make their own design by extending and improving it.

We start using the Arduino using the board named Arduino UNO.

The physical layout of Arduino UNO

Components of Arduino UNO

• Microcontroller: The major component of the Arduino board is the microcontroller. The microcontroller is fabricated inside an integrated chip and it performs the arithmetic/logical operation required for the particular task. Also, it communicates with peripheral devices, reads input devices and writes to output devices. Arduino UNO uses an ATmega328P microcontroller.
• Digital I/O pins: For connecting the sensors/input devices and output devices the board has digital I/O pins (0-13). These pins are used either as input or as output based on the requirement. Pins 0 and 1 are used in serial communication where pin 0 is used for reception serial information and pin 1 is used for transmission.
• Analog input pins: Analog input pins (0-5) are used to give analogue inputs directly to the board.
• USB plug: USB plug for uploading the program and communicating with the computer. This also provides a power supply during the development stage of a project.
• External power supply: This is used to power the Arduino board when it is not connected to the computer.
• Board power supply pins: Used to provide power to peripheral devices.
• Reset button: A push button is used to reset the Arduino.
• In-circuit serial programmer

Installing Arduino IDE

1. Download the latest Arduino integrated development environment (IDE) from the link https://www.arduino.cc/en/software .
2. Click on the Arduino software.

3. Click on I agree

4. Click on next

5. Click on install. (If you want change in the destination folder, change to required destination and click install).

6. Now installation will start and wait for the completion of installation. At the end of installation following dialogs will popup. Click on install button for all the three dialogs.

Connecting the Arduino UNO to the computer

Connect the Arduino board to the computer using a USB cable.

Now the Arduino board will be automatically detected. (The same can be verified using device manager).

Writing first Arduino sketch/program

Instruction writing to Arduino is done using the Arduino programming language. These programs are also called sketches. This section demonstrates how to write a simple Arduino program.

Required components:

• Arduino UNO board
• USB cable provided with Arduino UNO board

Arduino UNO board contains a built-in LED. This LED is connected to pin digital pin 13.

Therefore the simplest task performed using the Arduino is bilking that LED for a particular interval of time.

Arduino IDE visual appearance

Open the Arduino IDE. The following window is displayed having File, Edit, Sketch, Tools and Help options. It also has quick access buttons Verify, Upload, New, Open, Save and Serial monitor options. The editor space is provided to write the Arduino program. At the bottom, there is a message area which displays feedback of different processes performed on the sketch.

The following steps are performed to write and upload the new sketch.

1. Writing the new sketch

To write a new sketch, go to File and click New (This can also be done using the New quick access button). This will create a blank sketch. Now write the Arduino program inside the sketch.

// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(LED_BUILTIN, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
  digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (HIGH is the voltage level)
  delay(1000); // wait for a second. The delay given in terms of milliseconds
  digitalWrite(LED_BUILTIN, LOW); // turn the LED off by making the voltage LOW
  delay(1000); // wait for a second
}

2. Saving the Sketch

Now go to File and save the file with the required name (This can also be performed using quick access button Save).

3. Verifying (compiling) the sketch/Program

Compile the sketch by clicking verify button.

If the code gets compiled successfully, then the ‘Done compiling’ message will appear in the message area.

4. Uploading the sketch

The upload button compiles the sketch and uploads the program to the board.

If the code gets uploaded to the Arduino board successfully, then the ‘Done Uploading’ message will appear in the message area.

Now you can see the LED blinking for 1 second. Also, this can be re-verified for different values of delays.

Congratulations. You have successfully installed Arduino IDE and are ready to explore the Arduino projects.

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The post Getting Started with Arduino UNO first appeared on Student Projects.

Components required:

Principle:

IR sensors are used in the detection of objects, and obstacles. IR light is emitted from the IR emitter, which falls on the object and then reflects back. This reflected IR light is captured using an IR receiver and used to conclude the presence of the object. If the object is in the vicinity of the IR module, then the object’s presence can be detected. Otherwise, the object is said to be absent.

The IR sensor module has an IR emitter and receiver in the same module. The diagram below shows the IR sensor module.

The IR module contains 3 pins for the interface. Out of 3 pins two pins are VCC (3.3V/5V) and GND power supply. The OUT pin is the output pin which goes to a HIGH state when the object is present. When no object is detected OUT pin will stay at a LOW state. The major components in the module are the OP-AMP comparator, trim-pot, power LED and output LED. Trim-pot is used to change the sensitivity of the IR module (by varying the trim-pot we can change the distance at which the sensor can detect the object).

Circuit diagram:

Procedure:

1. Connect the IR module’s VCC and GND pins to Arduino’s +5V and GND pins respectively as shown in the circuit diagram.
2. Connect the OUT pin of the IR module to the Arduino board (pin 2) and declare it an input pin.
3. From the Arduino board connect the output (pin 7) to the +ve terminal of the LED. Connect –ve terminal of the LED to ground
4. Write the code in Arduino UNO software and run the program.
5. Move the object in front of the IR module and see the LED turning ON which indicates the presence of the object.

Working of object detection:

Whenever there is an object in front of the IR module, OUT of the IR module goes high. The IR module’s OUT pin is connected as the input to the Arduino board. The microcontroller in the Arduino board reads this signal and can conclude whether there is an object or not. The output is indicated through the LED connected to the Arduino board (shown in the breadboard).

The distance of the measurement (sensitivity) can be changed by varying the trim-pot. Variation in the trim-pot changes the reference voltage of the OP-AMP comparator. This

Flowchart for object detection:

Arduino Program for object detection:

int in_IRSensor = 2; // connect ir sensor to arduino pin 2
int out_LED = 7; // conect Led to arduino pin 13
void setup() 
{
  pinMode (in_IRSensor, INPUT); // sensor pin INPUT
  pinMode (out_LED, OUTPUT); // Led pin OUTPUT
}
void loop()
{
  int status_IR = digitalRead (in_IRSensor); //Read the IR sensor output
  if (status_IR == 1)
  {
    digitalWrite(out_LED, HIGH); // high on LED indicates object detected
  }
  else
  {
    digitalWrite(out_LED, LOW); // low on LED indicates no object present
  }  
}

The post Object Detection using the Arduino UNO first appeared on Student Projects.

In this article, we would interface an ultrasonic sensor (HC-SR04) with raspberry pie 4 to measure the distance of an object or obstacle. HC-SR04 is the sensor device that is specially used to measure the distance of an object within the range of 2mm to 400 cm. The ultrasonic sensor works on the principle of measuring the propagation time of the sound waves in between sending and receiving signals. HC-SR04 sends 40KHz signals (8 bursts) for the detection of an object then the time is calculated for the 40KHz signal hitting the object and coming back. That time would be our measured distance. Now, this HC-SR04 sensor has to be interface with a microcontroller or microprocessor to control it in the desired way. In this project, we are gonna use the Raspberry Pi 4 board.

List of All the Components:

Below are the components listed, that are used to make this project.

• HC-SR04
• Raspberry Pi 4
• 680 Ω Resistor (1/4 Watt) resistor
• 1.5 KΩ Resistor (1/4 Watt) resistor
• Connecting wires
• Laptop or Computer (For the programming of Raspberry Pi)

HC-SR04

HC-SR04 is an ultrasonic sensor, its working principle has been explained above. The picture of the sensor is shown below. From the picture, it can observe that the sensor has 4 pins (Vcc, Trig, Echo, and GND). VCC is for the supply voltage and GND for the ground.

Now to send the 40KHz signal into the Air, the Trig PIN must be set high through the Raspberry Pi for at least 10us. As the ultrasonic signals go in the air, the ECHO pin also gets high and it remains high until the 40KHz hit the object and reaches back to the sensor. So the distance is calculated for the time ECHO was HIGH.

Raspberry Pi 4

Raspberry Pi 4 is a microprocessor board that runs on Linux. It is a mini-computer, that is used to control electrical components like an ultrasonic sensor. It has some sets of inputs and outputs (GPIO) that allow connecting the electrical components in the desired way. The Pin configuration for the Raspberry pi 4 is shown below.

Design and working of the Circuit

When all the required components are ready, it is time to connect them. The noticeable thing here is that Raspberry works on the 3.3V of logic level, while the HC-SR04 works on 5 V. so their voltage compatibility is required. The Schematic of the Circuit is shown below.

The connections are, VCC of HC-SR04 is connected to the PIN 2 of the Raspberry Pi, the Trig pin is connected to the PIN 16 which is GPIO 23 on the Raspberry board, the Echo is to PIN 18 (GPIO 24), and GND to the Pin 20 on the Raspberry board.

Now the problem is we can’t directly put the Echo Pin of the sensor to the GPIO pin of the Raspberry board. Because the Echo Pin has a voltage of 5V while raspberry needs the 3.3V. so for their configuration, use a combination of 680Ω and 1.5 KΩ resistors are connected between their connection.

Working

The working of the project will be that the ultrasonic sensor would be triggered by the Trig Pin through the raspberry programming, then during the propagation and reflection of 40KHz wave, the Echo pin will provide a high signal to the one of GPIO pin of Raspberry pi as input. This input will be calculated by a program to calculate the distance of the object. The code for this project is given below:

import RPi.GPIO as GPIO
import time
try:
    GPIO.setmode(GPIO.BOARD)
    pinTrigger = 16
    pinEcho = 18
 
    GPIO.setup(pinTrigger, GPIO.OUT)
    GPIO.setup(pinEcho, GPIO.IN)
 
    GPIO.output(pinTrigger, GPIO.LOW)
    GPIO.output(pinTrigger, GPIO.HIGH)
 
    time.sleep(0.00001)
    GPIO.output(pinTrigger, GPIO.LOW)
 
    while GPIO.input(pinEcho)==0:
        pulseStartTime = time.time()
    while GPIO.input(pinEcho)==1:
        pulseEndTime = time.time()
 
    pulseDuration = pulseEndTime - pulseStartTime
    distance = round(pulseDuration * 17150, 2)
 
    print("Distance: %.2f cm" % (distance))
finally:
    GPIO.cleanup()

The post Raspberry Pi interface with Ultrasonic Sensor first appeared on Student Projects.

Design and verify full adder by using dataflow style with select statement

PROGRAM:

Library ieee;
use ieee.std_logic_1164.all; 
entity fa_select1 is
port(a,b,c:in bit; 
sum,carry:out bit); 
end fa_select1;
architecture df of fa_select1 is begin
with bit_vector'(a,b,c) select (sum,carry)<=bit_vector'("00") when "000" , bit_vector'("10") when "001",
bit_vector'("10") when "010",
bit_vector'("10") when "100",
bit_vector'("01") when "110",
bit_vector'("01") when "011",
bit_vector'("01" )when "101",
bit_vector'("11") when "111"; end df;

SIMULATION OUTPUT:

RESULT: Full adder is simulated and verified

The post Verilog program for Full Adder using dataflow style with select statement first appeared on Student Projects.

Design and verify full subtractor by using dataflow style with select statement.

PROGRAM:

library ieee;
use ieee.std_logic_1164.all; 
entity flsub_select is
port(a:in bit_vector(2 downto 0); 
s:out bit_vector(1 downto 0)); 
end flsub_select;
architecture beh of flsub_select is begin
with a select
s<=("00") when "000",
("11") when "001",
("11") when "010",
("01") when "011",
("10") when "100",
("00") when "101",
("00") when "110",
("11") when "111";
end beh; 

SIMULATION OUTPUT:

RESULT: Full subtractor using dataflow style with select statement is simulated and verified.

The post Verilog program for Full Subtractor by using a behavioral model with if,elsif& then statements. first appeared on Student Projects.

Design and verify full adder by using dataflow style with select statement.

PROGRAM:

Library ieee;
use ieee.std_logic_1164.all; entity fa_select is
port(a:in bit_vector(2 downto 0); 
s:out bit_vector(1 downto 0)); end fa_select ;
architecture beh of fa_select is begin
with a select
s<=("00")when"000",
("10")when"001",
("10")when"010",
("01")when"011",
("10")when"100",
("01")when"101",
("01")when"110",
("11")when"111";
end beh; 

SIMULATION OUTPUT:

RESULT: Full adder using dataflow style with select statement is simulated and Verified.

The post Verilog program for Full Adder by using dataflow style with select statement first appeared on Student Projects.

Here is a simple IR sensor-based security system which will detect any movement and triger an alarm. This circuit is ideal for use in houses, banks, stores, and other restricted areas where a movement-based alert alarm is required. This circuit is based on an IR sensor in which an IR beam is continuously falling on a photodiode, and an alarm is activated anytime this Infrared beam is broken by any form of movement.

The circuit schematic is shown below.

This security burgler alarm circuit is simple to build and only requires a few components, which are mentioned below.

IR LED

An IR LED (infrared light-emitting diode) is a special-purpose LED that emits infrared rays with wavelengths ranging from 700 nm to 1 mm. So it is invisible to human eyes. IR LEDs are more commonly used in security systems and remote control devices.

Photodiode

A photodiode is a semiconductor device with a P-N junction that converts light into an electrical current. The resistance and output voltage of the photodiode alter in response to the amount of infrared light received.

LM358

The LM358 is an operational amplifier (Op-Amp), and it is used as a voltage comparator in this design. The LM358 contains two independent voltage comparators. We have used only one comparator, with inputs at PINs 2 and 3 and outputs at PIN 1. The voltage comparator has two inputs: one inverting and the other non-inverting (PIN 2 and 3). The output of the comparator (PIN 1) is High when the voltage at the non-inverting input (+) is greater than the voltage at the inverting input (-). If the inverting input (-) has a higher voltage than the non-inverting end (+), the output is LOW.

NE555

The 555 Timer is is configured as a monostable mode in this example. When a falling edge is detected on pin 2(trigger pin), the output voltage rises high for a predetermined duration.

Working of an IR Sensor

An IR LED serves as the emitter, while an IR photodiode serves as the detector. An IR LED emits infrared light, which is detected by the IR photodiode. The resistance and output voltage of the photodiode alter in response to the amount of infrared light received. In this circuit we will detect when there is no light falling on the photodiode and trigger an alarm.

How does the IR based burgler alarm circuit work?

As per the circuit diagram given above, a variable resistor is connected to inverting end of LM358(Pin 2) to adjust the sensitivity of the sensor. A junction of the photodiode and a resistor is connected to the non-inverting end of LM358(Pin 3). LM358 op-amp voltage comparator’s output (PIN1) is connected to the 555 timer’s Trigger pin. The 555 Timer is set to monostable mode in this example.

When the circuit is switched ON and when there is IR radiation towards the photodiode, the voltage across it drops, while the voltage across the series resistor R2 increases. Non-inverting end (pin 3) gets high voltage when compared to inverting end (pin2). Hence the output of the comparator is HIGH, because the comparator output is connected to the 555 timer’s trigger pin, the 555 output is low when Trigger pin 2 is high. As a result, the 555 timer output remains LOW when the IR rays fall on the Photodiode. Read this article to learn how the IR sensor works with the LM358 comparator.

Now when the IR radiation towards the photodiode breaks due to some movement, the voltage across it increases, while the voltage across the series resistor R2 decreases. Non-inverting end (+) gets low voltage when compared to inverting end (-). Hence the output of the comparator is LOW, because the comparator output is connected to the 555 timer’s trigger pin, the 555 output is HIGH when Trigger pin 2 is low. As a result, the 555 timer output becomes HIGH and the he buzzer beeps for a short time. By altering the value of resistor R1 or capacitor C1, the duration of the beep can be lengthened.

Inverting end of LM358 is connected to the 10k pot. Make the necessary adjustments to ensure that voltage comparison works properly.

So, give it a shot and let me know if you have any questions in the comments section below. I’ll be happy to assist you!

The post IR Based Security Alarm Circuit first appeared on Student Projects.

Here is the circuit diagram.

This car parking sensor circuit is simple to build and only requires a few components, which are mentioned below.

IR LED

An IR LED (infrared light-emitting diode) is a special-purpose LED that emits infrared rays with wavelengths ranging from 700 nm to 1 mm. So it is invisible to human eyes. IR LEDs are more commonly used in security systems and remote control devices.

Photodiode

A photodiode is a semiconductor device with a P-N junction that converts light into an electrical current. The resistance and output voltage of the photodiode alter in response to the amount of infrared light received.

LM358

The LM358 is an operational amplifier (Op-Amp), and it is used as a voltage comparator in this design. The LM358 contains two independent voltage comparators. We have used only one comparator, with inputs at PINs 2 and 3 and outputs at PIN 1. The voltage comparator has two inputs: one inverting and the other non-inverting (PIN 2 and 3). The output of the comparator (PIN 1) is High when the voltage at the non-inverting input (+) is greater than the voltage at the inverting input (-). If the inverting input (-) has a higher voltage than the non-inverting end (+), the output is LOW.

Working of an IR Sensor

An IR LED serves as the emitter, while an IR photodiode serves as the detector. An IR LED emits infrared light, which is detected by the IR photodiode. The resistance and output voltage of the photodiode alter in response to the amount of infrared light received. The IR sensor’s basic functioning concept is shown below.

How does the Reverse Car Parking Sensor circuit work?

As per the circuit diagram given above, a variable resistor is connected to inverting end of LM358(Pin 2) to adjust the sensitivity of the sensor. A junction of the photodiode and a resistor is connected to the non-inverting end of LM358(Pin 3).

When the circuit is switched ON and when there is no object near the IR LED and photodiode, then there will be no IR radiation towards the photodiode. Hence the voltage across series resistor R2 decreases. Non-inverting end (pin 3) gets less voltage when compared to inverting end (pin2). Hence the output becomes LOW and the LED turns OFF.

Now when there is an object near the IR LED and photodiode, the photodiode absorbs the IR generated by the IR LED after it is reflected by the object. When reflected IR hits the photodiode, the voltage across it drops, while the voltage across the series resistor R2 increases. Non-inverting end (pin 3) gets high voltage when compared to inverting end (pin2). Hence the output becomes HIGH and the LED turns ON.

Inverting end of LM358 is connected to the 10k pot. Make the necessary adjustments to ensure that voltage comparison works properly.

So, give it a shot and let me know if you have any questions in the comments section below. I’ll be happy to assist you!

The post Reverse Car Parking Sensor Circuit first appeared on Student Projects.

You must use a relay if you want to connect any heavy load. The Relay connection with the Dark Activated automated Light switch is shown in the circuit diagram below.

Circuit diagram

Components required

100k Ohm Potentiometer is a variable resistor that is used to change the trigger point for the LED. That is, how much light is needed for the LED to turn ON and OFF. You can also use a 50k Resister in the place of a variable resistor.

BC547 is an NPN transistor that is used to amplify the current. When there is a small current at its base, it controls the large current at its collector and emitter end.

1N4007 is a PN junction rectifier diode. This allows only the flow of electrical current in one direction only. So, it can be used for the conversion of AC power to DC.

A relay is an electrically operated switch.

How does it work?

During the daytime when there is a light, the LDR has very low resistance and all voltage coming through R1 dropped with the ground. This makes the voltage at the base of the transistor very low and it will not switch ON the transistor. Because the transistor is OFF, the current will not flow through the transistor. As a result, the relay will not be switched ON and the bulb remains OFF.

At night when there is no light, the LDR has high resistance and very less power dropped with the ground. This makes the voltage at the base of the transistor high to turn the transistor ON. Because the transistor is turned ON, current flows through the transistor. It flows from the positive battery terminal, through R2, the relay, and the transistor down to the negative battery terminal. As a result, the relay turns ON and hence the bulb turns ON.

The same circuit can be used for a variety of purposes.

So, give it a shot and let me know if you have any questions in the comments section below. I’ll be happy to assist you!

The post Automatic Street Light Control System using LDR first appeared on Student Projects.

Circuit diagram

Components required

100k Ohm Potentiometer is a variable resistor that is used to change the trigger point for the LED. That is, how much light is needed for the LED to turn ON and OFF. You can also use a 50k Resister in the place of a variable resistor.

BC547 is an NPN transistor that is used to amplify the current. When there is a small current at its base, it controls the large current at its collector and emitter end.

How does it work?

During the daytime when there is a light, the LDR has very low resistance and all voltage coming through R1 dropped with the ground. This makes the voltage at the base of the transistor very low and it will not switch ON the transistor. Because the transistor is OFF, the current will not flow through the transistor. As a result, LED will not turn ON.

At night when there is no light, the LDR has high resistance and very less power dropped with the ground. This makes the voltage at the base of the transistor high to turn the transistor ON. Because the transistor is turned ON, current flows through the transistor. It flows from the positive battery terminal, through R2, the LED, and the transistor down to the negative battery terminal. As a result, the LED turns ON.

The same circuit can be used for a variety of purposes. Check out the Automatic Street Light Control System using LDR application. Instead of LED, bulbs are used using a relay.

So, give it a shot and let me know if you have any questions in the comments section below. I’ll be happy to assist you!

The post Automatic night light using LDR first appeared on Student Projects.