Component reference

Popular IoT sensors & actuators, with approximate India prices

A quick-reference sheet for common components used in Arduino / Raspberry Pi / ESP32 based IoT projects — original illustrated figures, typical use, and retail prices from Indian sellers.

Sensors

Devices that read something from the environment and turn it into a signal.

DHT11 / DHT22

Measures temperature and humidity for climate monitoring.

₹80 – ₹350

HC-SR04 Ultrasonic

Measures distance using sound wave echo timing.

₹60 – ₹120

PIR Motion Sensor

Detects movement of people or animals via body heat.

₹70 – ₹150

LDR (Light Sensor)

Detects ambient light level for auto-lighting projects.

₹20 – ₹60

MQ-2 Gas Sensor

Detects smoke and gases like LPG, methane, propane.

₹80 – ₹150

IR Obstacle Sensor

Detects nearby objects using infrared reflection.

₹30 – ₹80

Soil Moisture Sensor

Reads soil water content for smart irrigation.

₹40 – ₹90

Rain Sensor Module

Detects rainfall for weather stations and covers.

₹50 – ₹100

Load Cell + HX711

Measures weight for smart scales and IoT dispensers.

₹150 – ₹300

Flame Sensor

Detects open flame or fire for safety alarms.

₹30 – ₹70

Sound Sensor Module

Detects clap or sound intensity to trigger actions.

₹40 – ₹80

GPS Module (NEO-6M)

Provides live location coordinates for tracking.

₹450 – ₹700

Actuators

Devices that take a signal and turn it into physical action.

Buzzer (Active)

Produces sound for alerts and alarms.

₹10 – ₹30

Relay Module

Switches high-power devices using a low-power signal.

₹50 – ₹100

Servo Motor (SG90)

Moves to a precise angle for arms, gates, and latches.

₹120 – ₹200

DC Motor

Provides continuous rotation for wheels and fans.

₹30 – ₹90

Stepper Motor (28BYJ-48)

Moves in exact steps for precise positioning tasks.

₹150 – ₹250

Solenoid Valve

Opens or shuts fluid flow for water/irrigation systems.

₹300 – ₹600

Mini Water Pump

Pushes water for auto-watering or liquid dispensing.

₹80 – ₹150

LED (Indicator)

Gives visual status feedback for a project's output.

₹1 – ₹5

Figures are original simplified illustrations (not photographs) meant to show the recognizable shape of each module. Prices are approximate street/retail rates on Indian electronics marketplaces (Robu, Robocraze, Amazon India, local shops) and vary by seller, quantity, and module quality — check current listings before buying.