Pick a sensor by what it must measure, then by range and output type. A DHT22 reads temperature and humidity on one pin. An HC-SR04 reads distance from 2 to 450 cm. A PIR sensor detects motion up to 7 m away. Check voltage and pins before you buy. This guide compares the common Arduino sensors.
Which sensor reads temperature and humidity?
The DHT22 reads temperature from -40 to 80 degrees C and humidity from 0 to 100 percent. It uses one data pin and runs on 3.3 to 5.5 V.
A 37-in-1 starter kit adds a DHT11, a relay, and a joystick module. It suits a first sensor project with a UNO R3 board.
How does an ultrasonic sensor measure distance?
The HC-SR04 sends a sound pulse and times its echo. It reads distance from 2 to 450 cm with 0.3 cm precision.
It needs 5 V power and two pins: trigger and echo. Mount it level, or the echo will miss the target.
Which sensor detects motion for a robot or camera?
The HC-SR501 PIR sensor detects motion up to 7 m away. It runs on 5 to 20 V with an adjustable delay from 0.3 to 18 seconds.
A PIR sensor suits a wildlife camera or a security camera. It wakes the camera only when motion crosses its 110 degree field.
How do you read air pressure and altitude?
The BMP280 reads pressure from 300 to 1100 hPa with plus or minus 1 hPa accuracy. It also reads temperature on the same chip.
It talks over I2C or SPI at 3.3 V or 5 V. Pair it with an OLED display to show pressure and altitude.
Which sensor follows a line under a robot car?
The TCRT5000 reads a dark line from 1 to 25 mm below the sensor. It outputs a digital signal through an LM393 comparator.
A 4-pack gives one sensor per wheel side with spares. Mount each sensor 10 mm above the track for a clean reading.
Which sensor detects gas and smoke?
The MQ-2 detects LPG, methane, propane, and smoke on one module. It needs a warm-up near 20 seconds before readings settle.
It outputs an analog voltage that rises with gas level. Calibrate it in clean air, then set your alarm threshold above that baseline.
Frequently asked questions
Can one Arduino pin read a DHT22?
Yes. The DHT22 uses a single-bus protocol on one digital pin. The Arduino DHT library handles the timing for you.
How far can an HC-SR04 read?
It reads from 2 to 450 cm. Soft surfaces and angled walls shorten the range, so test it on your target first.
Does a PIR sensor work outdoors?
Yes, but sunlight and wind can trigger false alarms. Mount it in shade and aim it away from moving branches.
What is the difference between DHT11 and DHT22?
The DHT22 reads -40 to 80 degrees C, while the DHT11 reads 0 to 50 degrees C. The DHT22 also reads humidity more precisely.
Parts used
HC-SR04 Ultrasonic Ranging Sensor Module for Arduino, 2-450cm, with Mounting Bracket Options, $4.01. HC-SR04 ultrasonic ranging module for Arduino. 2-450cm detection range, 0.3cm precision, 5V. Sensor only or with acrylic mounting bracket. Ships from NY, USA.
DHT22 / AM2302 Digital Temperature & Humidity Sensor Module, $5.96. DHT22 / AM2302 digital temperature and humidity sensor module. 0: 100% RH, -40 to 80°C, 3.3: 5.5V, single-bus output for Arduino and ESP32. Ships from NY, USA.
BMP280 Barometric Pressure & Temperature Sensor Module, 5-Pack / 10-Pack, 3.3V & 5V, $6.77. BMP280 barometric pressure and temperature sensor module. 300: 1100 hPa, ±1 hPa accuracy, I2C/SPI, 3.3V or 5V. 5-packs and 10-packs for Arduino and ESP32. Ships from NY, USA.
HC-SR501 PIR Motion Sensor Module, 2-Pack, $7.62. HC-SR501 PIR motion sensor module for Arduino and Raspberry Pi. 5: 20V, adjustable 0.3: 18s delay, up to 7m detection, <120° cone. 2-pack. Ships from NY, USA.
MQ-2 Smoke & Combustible Gas Sensor Module, $5.81. MQ-2 smoke and combustible gas sensor module for Arduino. Detects LPG, methane, propane, butane, alcohol, hydrogen, smoke : 300: 10,000ppm, 5V heater. Ships from NY, USA.
IR Infrared Obstacle Avoidance Sensor Module, 5-Pack / 10-Pack, $6.20. IR infrared obstacle avoidance sensor module for Arduino and robot cars. 2: 30cm adjustable detection, 35° angle, LM393 comparator, 3.3: 5V. 5-packs and 10-packs. Ships from NY, USA.
TCRT5000 Infrared Reflective Line Tracking Sensor Module, 4-Pack, $7.02. TCRT5000 infrared reflective line tracking sensor module. 1: 25mm adjustable detection, LM393 comparator, digital output, 3.3: 5V. 4-pack for Arduino robot cars. Ships from NY, USA.
WAVGAT 37 in 1 / 45 in 1 Sensor Modules Starter Kit for Arduino UNO R3 / MEGA2560, $30.95. WAVGAT 37 in 1 / 45 in 1 sensor modules starter kit for Arduino UNO R3 and MEGA2560. HC-SR04, DHT11, relay, joystick, laser, buzzer and more. Loose or with storage box. Ships from NY, USA.
UNO R3 Compatible Development Board, ATmega328P CH340G : USB / Type-C, $9.27. UNO R3 compatible development board with ATmega328P and CH340G USB-serial, 16MHz, 14 digital I/O and 6 analog inputs. Works with the Arduino IDE. USB-B or Type-C, with or without cable. Ships from NY, USA.
0.96 Inch OLED Display Module, SSD1306, I2C, 128×64, for Arduino / ESP32 / ESP8266, $5.47. 0.96 inch OLED display module, SSD1306 driver, 128×64 pixels, I2C interface, 4 pins (GND, VCC, SCL, SDA), 3.3V-5V. Works with Arduino, ESP32, ESP8266, and Raspberry Pi. Choose yellow-blue, white, or blue display. Ships from NY, USA.
Microcontrollers and Development
Related buying guides on Quality RC Parts
How to Choose the Right Sensor for Arduino Projects
How to Choose Sensor Modules for Your Arduino Projects
How to Build Your Arduino Sensor Kit for Robot Projects
Browse all the guides on the Quality RC Parts Drone Guides hub, or start at the Quality RC Parts store.
Sources
Quality RC Parts stocks parts in New York, USA and ships in-stock orders in 1-2 business days.
Last updated: 2026-11-10.