TASK 9: Tinkercad
Objective: The objective of this task was to create a tinkercad account & to make a simple circuit to estimate the distance between the ultrasonic sensor and the object.
Methodology:
For this project we’ll need the below components: 
The connections made are as follows:
| Ultrasonic Sensor | Arduino UNO |
|---|---|
| VCC | 5v |
| TRIG | Pin 8 |
| ECHO | Pin 9 |
| GND | GND |
P.S: Here the Pins 8,9 & 3 are Digital PWM pins on the Arduino.
| LCD (16x2) 12C | Arduino UNO |
|---|---|
| VCC | 5v |
| SDA | Blank pin |
| SCL | Blank pin |
| GND | GND |
| Servo Motor | Arduino UNO |
|---|---|
| Ground | GND |
| Power | 5V |
| Signal | Pin 3 |
This is how the circuit looks after all the connections
Outcomes & Learnings:
- Working of the Ultrasonic sensor:
The term "ultrasonic" refers to frequencies higher than 20 kHz, which are inaudible to humans because they exceed the upper limit of the human hearing range. Ultrasonic sensors typically have two cylindrical components protruding outward: a transmitter (T) and a receiver (R). The transmitter emits ultrasonic sound waves, which interact with an object in front of the sensor and reflect back to the receiver.
The distance between the ultrasonic sensor and the object is calculated based on the time it takes for the reflected ultrasonic wave to reach the receiver. The formula used for this calculation is:
𝑑=𝑠⋅𝑡
where:
- 𝑑 = Distance between the object and the ultrasonic sensor
- s = Speed of the ultrasonic wave signal
- t = Time taken by the reflected signal to reach the receiver
To increase the range and coverage area of the ultrasonic sensor, it can be mounted on a servo motor, allowing it to rotate. This setup enables the sensor to act as a radar, scanning a wider area and providing better distance measurements.
Click here to view my simulated circuit
TASK 10: Speed control of DC motor using L298N driver
Objective: Understand the control DC motors using the L298N motor driver and the Arduino board. Using an UNO and H-Bridge L298N motor driver, control the speed of a 5V motor.
Methodology:
For this project we’ll need the below components:
The connections made are as follows:
| Potentiometer | Arduino UNO |
|---|---|
| Ground | GND |
| Power | 5v |
| Central pin | A0 |
| L298N motor driver | Components |
|---|---|
| ENA | ~10 of Arduino UNO |
| IN1 | 8th Digital pin of Arduino UNO |
| IN2 | ~9 of Arduino UNO |
| GND | -ve of 9 v power supply |
| 12V | +ve of 9 V power supply |
| Output 1 | One terminal of DC motor |
| Output 2 | 2nd terminal of DC motor |
Note: Here the ENA pin should be compulsorily connected to a PWM (~) pin of the Arduino
This is how the circuit looks after all the connections
Outcomes & Learnings:
- Working of a L298N motor driver:
I learned about the various ports and pins present in the L298N motor driver.
2.Speed Controlling using an L298N driver:
The speed of a DC motor can be controlled by changing its input voltage. A widely used technique to accomplish this is Pulse Width Modulation (PWM). PWM is a technique in which the average value of the input voltage is adjusted by sending a series of ON-OFF pulses. This average voltage is proportional to the width of the pulses, which is referred to as the Duty Cycle. The higher the duty cycle, the higher the average voltage applied to the DC motor, resulting in an increase in motor speed. The shorter the duty cycle, the lower the average voltage applied to the DC motor, resulting in a decrease in motor speed.
Note: The pins in L298N driver which are responsible for speed control are ENA & ENB, these pins should be compulsorily connected to the PWM (~) ports of the Arduino UNO, so that PWM takes place.
Here are the glimpses of me performing this task:
TASK 11: LED Toggle Using ESP32
Objective: Learn the working of an ESP32 and create a standalone web server with an ESP32 that controls the LED connected with ESP32 GPIOs.
Methodology:
For this project we’ll need the below components:
The connections made are as follows:
After feeding the required code into the ESP32 microcontroller enter the mobile hotspot credentials into the code & change the baud rate to 115200, later during the compilation of the code when you receive an IP address, paste the same into your browser and toggle the LED using the same website.
Outcomes & Learnings:
Here are the glimpses of me performing this task:
TASK 12: Soldering Prerequisites
Objective: Learn about the soldering equipment and perform basic soldering on a perf board, for example a LED circuit.
Methodology:
My first experience soldering an LED onto a perf board was great. I inserted the LED leads through the correct holes, ensuring proper orientation. Then, I heated the soldering iron and kept it on the junction of the lead and copper pad, feeding solder wire into the joint for a solid connection. Later cross checked if the connections were strong.
TASK 13: 555 IC astable multivibrator with 60% duty cycle
Objective: Design a 555 IC astable multivibrator with 60% duty cycle.
Methodology:
For this project we’ll need the below components:
| Name | Component | Quantity |
|---|---|---|
| U1 | 555 IC Timer | 1 |
| C1 C2 | 0.01 uF Capacitor | 2 |
| R1 | 10 kilo ohms | 1 |
| R2 | 20 (10+10) kilo ohms | 1 |
| V1 | VRPS- 5V | 1 |
The connections are made on the breadboard as shown in the circuit diagram below:
Outcomes & Learnings:
- I learned the general working of a 555 IC timer, along with the truth table of S-R flip flop.
- The formula used to calculate, ratio of the resistors to be used while designing a astable multivibrator for a given % of duty cycle is:
- All the above knowledge helped me learn, how to design an astable multivibrator using the 555 IC timer. The duty cycle I got while performing this project is 59.5% while the expected result being 60%
TASK 14: K-Map & Deriving Logic Gates
Objective: Determine the Karnaugh map and make a burglar alarm using simple logic circuits. The buzzer or led blinks when certain conditions are met, you can use push buttons for the door and key.
Methodology:
Since this is a burglar alarm, it should start ringing in case of un-authorised access i.e. when the door opens in the absence of the key. So, let’s make the following assumptions:
We denote state of:
- Door by, ‘D’. Open door is denoted by 1, closed door is denoted by 0.
- Key by, ‘K’. If key is NOT put on the door it’s denoted by 0 and if key is put on the door it’s denoted by 1.
- The burglar alarm is denoted by, ‘A’ where 1 means the alarm is activated and 0 means the alarm is off.
So, the alarm works on the basis of the given truth table: 
K-map obtained from the given truth table is:
Outcomes & Learnings:
Since we can see that the solution of the given k-map is, D1 K0. The Logic circuit representing this is as shown below,
Below is the simulation of the logic circuit I designed for burglar alarm:
TASK 15: Active Participation
I won 1st place in the Kagada 2023 Project making competition, my project was about converting heat energy from railway tracks to electricity using Thermo Electric Generators (TEGs), which works on the principle of seebeck effect. Below is the image of my certificate I received,
TASK 16: Datasheets report writing
Objective: Study the datasheet of L293D motor driver and write a report on it. Specify about the ICs used in L293D, PWM, H-bridge etc.
Outcomes & Learnings:
- The L293D is a dual-channel H-Bridge motor driver capable of driving a pair of DC motors or a single stepper motor. This means it can drive up to two motors individually which makes it ideal for building a two-wheeled robotic platform. The L293D is most often used to drive motors, but can also be used to drive any inductive load such as a relay solenoid or large switching power transistor. It is capable of driving four solenoids, four uni-directional DC motors, two bi-directional DC motors or one stepper motor. The IC also includes built-in kick-back diodes to prevent damage when the motor is de-energized.
The L293D IC has a supply range of 4.5V to 36V and is capable of 1.2A peak output current per channel, so it works very well with most of our motors.
| Components | Range |
|---|---|
| Motor output voltage | 4.5V - 36V |
| Logic input voltage | 5V |
| Output Current per channel | 600mA |
| Peak Output Current per Channell | 1.2A |
The following images shows the L293D pins:
- PWM – to control speed:
The speed of a DC motor can be controlled by changing its input voltage. A common technique to do this is to use PWM (Pulse Width Modulation). PWM is a technique where the average value of the input voltage is adjusted by sending a series of ON-OFF pulses. The average voltage is proportional to the width of the pulses known as the Duty Cycle. The average voltage is proportional to the width of the pulses known as the Duty Cycle. - H-Bridge – to control the rotation direction:
The spinning direction of a DC motor can be controlled by changing the polarity of its input voltage. A common technique for doing this is to use an H-bridge. An H-bridge circuit consists of four switches with the motor in the centre forming an H-like arrangement. Closing two specific switches at a time reverses the polarity of the voltage applied to the motor. This causes a change in the spinning direction of the motor.