The TTP223B Capacitive Touch Sensor Module is a compact digital touch switch that detects finger touch using capacitive sensing technology. Operating from 2V to 5.5V DC, it provides a simple HIGH/LOW digital output and can work through suitable thin non-metallic surfaces. It is ideal for Arduino, ESP32, STM32, home automation, robotics, DIY electronics, and touch-controlled projects.

The Piezoelectric Knock Vibration Sensor Switch Module detects knocks, taps, vibrations, and impacts with adjustable sensitivity. It provides both digital TTL and analog outputs for easy integration with Arduino, ESP32, Raspberry Pi, and other microcontrollers. Featuring an onboard LED indicator and compact design, it is ideal for security systems, alarms, automation, robotics, and DIY electronics projects.

The DHT22 Humidity and Temperature Sensor Module is a reliable digital sensor designed to measure temperature and relative humidity with good accuracy. It uses a capacitive humidity sensor and thermistor and provides calibrated digital output through a single data pin. With a 3V–5V operating voltage, wide measurement range, and low power consumption, it is ideal for IoT, weather stations, HVAC, home automation, agriculture, and environmental monitoring projects.