Electronics and robotics
Electronics and robotics projects for college and diploma: 57 ideas.
Each project below opens to its own page with what it shows, the science behind it, the materials, safety, step-by-step instructions, what you should see and viva questions. Many can be made from things at home; where a kit helps, the page links one.
Other subjects for college and diploma: Physics, Chemistry, Earth and space, Environment, Computing and coding.
Line follower robot
IR sensors shine infrared light at the floor: white reflects it and black absorbs it. The controller reads which sensor sees the line and steers the motors to stay on it.
Solar tracker with LDRs
Two LDRs compare the light on either side of the panel. The microcontroller turns a servo towards the brighter side, so the panel keeps facing the Sun and collects more energy through the day.
Home automation with NodeMCU
A Wi-Fi board receives commands from a phone app or web page and switches relays, so lights and fans can be controlled from the phone and on a schedule.
Automatic railway gate control
IR sensors detect the train before and after the crossing. The controller closes the gate with a servo and sounds a buzzer as a train approaches, and opens it again once the train has passed.
Fire-fighting robot
Flame sensors detect the infrared light from a flame. The robot steers towards the strongest reading and switches on a small pump to spray water at it.
Vehicle accident alert with GPS and GSM
An accelerometer detects a sudden impact or tilt. The controller reads the location from a GPS module and sends it by SMS through a GSM module to saved numbers.
RFID attendance system
Each card carries an RFID tag with a unique ID. The reader picks up the ID by radio when the card is held near it, and the controller logs the name and time.
Gas leakage detector
The resistance of an MQ-series gas sensor changes when LPG or smoke is in the air. The controller reads it and sounds a buzzer above a set level.
Bluetooth-controlled car
A phone app sends commands over Bluetooth to an HC-05 module. The Arduino reads them and drives the motors forwards, backwards, left and right through a motor driver.
Phone web page that switches a 12 V LED strip through an ESP8266 relay
A NodeMCU (ESP8266) joins the home Wi-Fi, runs a tiny web server and turns a relay on or off when a phone browser taps a button. The relay switches a 12 V LED strip, so the whole thing is a low-voltage copy of a smart switch.
RFID door latch that pulls a 12 V solenoid for tagged cards only
An RC522 reader reads the unique ID of a 13.56 MHz card or key fob. If the ID is in a list stored in the sketch, the Arduino fires a relay for three seconds that pulls a 12 V solenoid bolt open, and an LCD greets the user by name.
ESP32 energy logger measuring a 12 V load with an ACS712 current sensor
An ACS712 Hall-effect sensor measures the current through a 12 V DC load while a resistor divider measures its voltage. The ESP32 multiplies them for power, adds up watt-hours over time and shows the live figures on a phone over Wi-Fi.
Overhead tank level on your phone with automatic pump control (ESP8266)
An ultrasonic sensor on the tank lid measures the distance to the water surface. The ESP8266 converts that to a percentage, shows it on a phone page, and switches a 5 V pump through a relay to refill when the level is low and stop when full.
ESP32-CAM doorbell that sends a visitor snapshot to your phone
An ESP32-CAM board with its small camera takes a photo when the doorbell button is pressed or a PIR sees movement, and sends the picture to a free messaging bot on the owner's phone over Wi-Fi. It shows how a microcontroller can handle images and internet messages.
Earthquake alarm with an MPU6050 that cuts a 12 V supply through a relay
An MPU6050 accelerometer measures shaking on three axes. When the vibration stays above a level for a short time, the Arduino sounds a siren, flashes a light and opens a relay that cuts a 12 V model lighting circuit, as a real system might cut gas or power during a quake.
Two-zone drip irrigation with soil probes and a phone dashboard (ESP8266)
Two soil moisture probes in two pots each control their own 5 V pump through a relay, and a NodeMCU shows both moisture levels and pump states on a phone page. It demonstrates zone-wise watering, the way a farm drip system treats each bed separately.
Polyhouse logger that records light, temperature and humidity to an SD card
An Arduino with a DS3231 clock writes a time-stamped line of light, temperature and humidity readings to a micro SD card every ten minutes. Opened in a spreadsheet, the file shows how conditions inside a covered bed differ from outside over several days.
Water turbidity meter using a laser pointer and an LDR
A laser beam passes through a sample bottle to an LDR; cloudy water scatters light and the LDR reading falls. The Arduino converts the reading to a clarity scale calibrated with known mixtures and shows it on an LCD, a low-cost version of a turbidity meter.
Indoor air quality logger with MQ-135, an OLED and a phone graph (ESP32)
An MQ-135 sensor responds to carbon dioxide, ammonia, smoke and other indoor pollutants. An ESP32 shows a rolling value on an OLED, keeps the last hour of readings in memory and draws them as a graph on a phone page, so the effect of cooking, incense or a closed room is visible.
Dust particle logger with a GP2Y1010 sensor that triggers a 12 V filter fan
A Sharp GP2Y1010 optical dust sensor measures airborne particles by scattered infrared light. An Arduino logs the density, shows it on an LCD and switches a 12 V fan with a cloth filter through a relay when dust rises, a model of an air purifier.
Dual-axis solar tracker with four LDRs and two servos
Four LDRs in a cross with small dividing walls sense which side is brighter. Two servos tilt a small solar panel left-right and up-down until all four read the same, so the panel faces the sun. A voltmeter reading from the panel shows the gain over a fixed panel.
Clock-based solar tracker that follows the sun by time with a DS3231
Instead of light sensors, this tracker computes where the sun is from the date, time and the location, using the real-time clock, and turns a panel to that azimuth and elevation with two servos. It keeps pointing correctly even in cloud, when LDR trackers lose the sun.
Solar panel performance logger recording volts, amps and light to an SD card
An Arduino measures a small panel's voltage through a divider and its current through an INA219 sensor while a load resistor draws power, and logs both with light level and time to an SD card. The data shows how output changes with sun angle, cloud and panel temperature.
Sonar radar sweep: a servo-mounted ultrasonic sensor mapping a room on a laptop
Turning an ultrasonic sensor on a servo and sending angle and distance to a laptop builds a polar map of the objects around, like a radar sweep. It combines timing, servo control and serial communication.
Model door lock opened by a 4 digit keypad code and a servo bolt
The Arduino compares the keys typed with a stored code and turns a servo to slide a bolt only when they match. After three wrong tries it locks out for a minute, showing basic access control logic.
RFID card door opener with an MFRC522 reader that logs who entered
A passive RFID card has no battery: the reader powers it through radio waves and reads its unique ID. The Arduino checks the ID against a list and opens a servo door for known cards only.
Fingertip pulse sensor showing heartbeats on the Serial Plotter and a beat LED
Each heartbeat changes the amount of blood in the fingertip, and so changes how much light passes through or reflects. A green LED and a light sensor see this tiny change, which the Arduino turns into a beat rate.
Self-balancing two-wheel robot using an MPU6050 and a PID loop
An inverted pendulum falls over unless something keeps correcting it. The robot measures its tilt hundreds of times a second and drives the wheels under the falling body, which is feedback control with a PID algorithm.
Maze-solving robot using three ultrasonic sensors and the left-hand rule
A robot that always keeps a wall on its left will find the exit of a simply connected maze. It needs three distance readings and a small decision program, which shows how robots navigate.
Mini sumo robot that finds its opponent and stays inside the white-edged ring
Sumo robots search for an opponent, push it out of a black ring and stop at the white border. This needs edge detection with reflective sensors and distance sensing, with simple decision priority in the code.
Hand-tilt glove that drives a car wirelessly using MPU6050 and nRF24L01
A tilt sensor on a glove tells the car which way to go. The data is sent over a 2.4 GHz radio link by a pair of modules, so the car follows hand movements without a phone.
Barometer and altimeter with a BMP280 that detects which floor you are on
Air pressure falls with height, by about 12 pascals for each metre near the ground. A BMP280 sensor can measure this so precisely that it can tell one floor of a building from the next.
Wi-Fi signal strength heat map of a room measured with an ESP32
The strength of a radio signal, measured as RSSI in dBm, falls with distance and with obstacles like walls. Measuring it at grid points shows dead spots and where a router should be placed.
Internet clock showing Indian time on an OLED, set automatically by NTP
Computers set their clocks by asking time servers over the internet using the Network Time Protocol. A NodeMCU can do the same and display accurate Indian Standard Time without a clock chip.
ESP32 sensor node publishing temperature and light over MQTT to a laptop broker
MQTT is the light-weight messaging method behind many IoT systems. A sensor node publishes readings under named topics, and any subscriber, such as a laptop or a phone, receives them through a broker.
Digital kitchen scale built from a load cell, an HX711 amplifier and an Arduino
A load cell is a metal bar whose resistance changes by a tiny amount when it bends under a weight. The HX711 amplifies and digitises this change so the Arduino can show the mass in grams.
Colour sorter for beads or candies using a TCS3200 sensor and two servos
The TCS3200 sensor measures how much red, green and blue light an object reflects. The Arduino classifies the colour and uses a servo to drop the object into the right bin, a small model of an industrial sorting line.
555 monostable delay timer: calculated against measured pulse width
Staircase and passage lights, bell pushes and sample-and-hold stages all need a pulse of fixed length after a single trigger. A 555 timer in monostable mode gives such a pulse, and its length is set by one resistor and one capacitor. The project tests how close the formula T = 1.1 RC is to what a stopwatch measures.
LM317 adjustable 1.25 to 12 V bench supply with a load regulation test
Every student lab needs a variable DC supply, and shop-bought ones are costly. An LM317 regulator with two resistors gives an adjustable output. The project builds one from a 15 V adapter output and tests how much the output falls when the load current rises, which is the load regulation.
AA cell capacity tester with a constant-current load and Arduino logging
Rechargeable and cheap zinc cells carry a printed capacity that is often much higher than the truth. A constant-current load with an Arduino logger finds the real milliamp-hours of a cell by recording voltage until the cell reaches its cut-off.
Joule thief that lights an LED from a nearly flat 1.2 V cell
A single cell below 1 V cannot light a white LED, which needs about 3 V. A joule thief is a tiny blocking oscillator that pumps energy from the cell in short bursts and steps the voltage up. The project builds it and measures the pulse frequency, the output voltage and the extra running time.
LM386 audio amplifier with measured gain and frequency response
Small radios, intercoms and toy speakers use small audio power amplifiers. The LM386 gives gain of 20 or 200 with a few components. The project builds one and measures the voltage gain and how it changes with frequency, so that a student learns to read a Bode-style plot.
TV remote code decoder with a TSOP1738 receiver and Arduino
Infrared remotes talk to TVs and fans by sending pulses of 38 kHz light. An Arduino with a TSOP1738 receiver can decode the pulse train of each button, which teaches the idea of a protocol, and can then switch low-voltage loads from any old remote.
Thermistor thermometer calibrated with the Steinhart-Hart equation
A thermistor is cheap and sensitive but its resistance is not linear with temperature. By measuring resistance at three known temperatures and fitting the Steinhart-Hart equation, you can build a digital thermometer more accurate than a basic LM35 and show how calibration removes error.
LM2596 buck converter module: efficiency against load current
Phone chargers, LED drivers and solar chargers use switching converters because linear regulators waste power as heat. The project tests a ready-made LM2596 buck module and compares its efficiency with an LM7805 linear regulator at the same load.
PWM speed controller for a 12 V DC motor with an IR tachometer
Fans, conveyors and e-rickshaws vary motor speed by switching power on and off very fast rather than wasting it in a resistor. The project builds a PWM controller, measures real rpm with an infrared sensor and plots speed against duty cycle.
HX711 load cell kitchen scale with calibration and an error table
Digital weighing scales in shops use strain-gauge load cells, which change resistance by a tiny amount when bent. An HX711 amplifier and Arduino turn that into grams. The project calibrates the scale with known masses and reports its accuracy.
LoRa point-to-point sensor link: range and packet loss between two ESP32 nodes
Wi-Fi does not reach farms, dams or hill villages. LoRa radio reaches kilometres on a few milliwatts. The project builds a transmitter that sends soil moisture and temperature and a receiver that shows them, then measures signal strength, packet loss and range against distance, spreading factor and antenna height.
MQTT sensor network of three ESP32 nodes with a Mosquitto broker and Node-RED
Factories and smart buildings send small readings from many sensors to one place. MQTT is the light-weight publish-subscribe protocol for this. The project builds three ESP32 nodes that publish readings to a broker on a laptop, with Node-RED showing live charts and alerts, and tests behaviour when a node drops off.
GPS track logger with SD card storage and route plot on an open map
Delivery vans, school buses and trekkers need a record of where they went. A battery-powered logger with a GPS module stores time, position and speed on an SD card, and a Python script plots the track on a map and finds distance and average speed. The project tests accuracy against a phone and a known surveyed route.
MAX30102 pulse rate and SpO2 monitor compared with manual pulse counts
A pulse oximeter clips on a finger and shows pulse and blood oxygen using red and infrared light. A student can build a low-cost model with a MAX30102 sensor and an Arduino, display the readings, and test the pulse rate against a manual count. The project is for learning only and must not be used for medical decisions.
Fingerprint attendance system with an R307 sensor, RTC and SD card log
Proxy attendance is a problem in classes and workshops. A fingerprint module identifies a person on the spot and a log records the time. The project builds a stand-alone attendance box and a Python script that converts the log into a monthly report, with attention to consent and data protection.
Traffic signal controller in register-level C on an ATmega328P with a pedestrian request
Arduino code hides what a microcontroller does. Writing the program straight to the ATmega328P registers shows how ports, timers and interrupts work. The project builds a four-way traffic signal model with a state machine, timer interrupts and a pedestrian button, and measures timing accuracy.
Smart pill box with RTC reminders, lid sensors and a missed-dose log
Elderly patients often forget tablets. A seven-compartment box with an RTC alarm, LEDs and lid sensors can remind the user, detect which lid opened and record missed doses for a caregiver. The project designs and tests the device with candy in place of medicine and discusses safety and reliability.
PWM solar charge controller for a 12 V 7 Ah battery with cut-offs and logging
Small solar lighting systems fail when batteries are overcharged or deeply discharged. A charge controller protects them. The project builds one with an Arduino, a MOSFET switch and voltage and current sensing, with three-stage charging, low-voltage load disconnect and data logging, tested on a 12 V 7 Ah sealed lead-acid battery with a 20 W panel.
Four-axis servo robot arm with inverse kinematics solved in Python
Factory robots must place a gripper at an exact point. Inverse kinematics finds the joint angles that reach a point. The project builds a four-axis arm from acrylic and servos and solves the angles by trigonometry in Python, then measures positioning accuracy and repeatability.
Self-balancing two-wheel robot with an MPU6050, complementary filter and PID
A two-wheel robot is an inverted pendulum and falls unless it moves under itself fast enough. The project builds one with a gyroscope and accelerometer, fuses their data, and tunes a PID controller until the robot stands and recovers from pushes, recording the effect of each gain.