RFID EM18 The EM18 RFID reader module is designed to read RFID cards operating at a frequency of 125 kHz. When an RFID card enters the reader’s range, the card’s unique data is transmitted to the reader as an RF signal. The reader then converts this data into bytes and sends it through its serial …
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Introduction DTMF (Dual Tone Multi-Frequency) is a signaling technique in telecommunications that uses a combination of two pure tone frequencies (sine waves) to generate dial tones in telephones. When a key is pressed, a pair of tones—one low and one high frequency—is sent. There are 8 unique frequencies: 4 in a lower range and 4 …
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GSM SIM900 Global System for Mobile Communication (GSM) is a digital cellular network standard widely used for mobile devices and long-distance communication. Several GSM modules are available on the market, including the SIM900, SIM700, SIM800, SIM808, and SIM5320. The SIM900A module supports data transfer over GPRS, SMS sending and receiving, and voice calls. It communicates …
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Introduction Ultrasonic HC-SR04 Module The HC-SR04 ultrasonic module operates on the principles of SONAR and RADAR. This module features an ultrasonic transmitter, receiver, and control circuitry all integrated onto a single board. It has four pins: Vcc, Gnd, Trig, and Echo. When a pulse of 10µs or longer is sent to the Trig pin, the …
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DHT11 Sensor The DHT11 sensor is a digital humidity and temperature sensor with a single-wire interface, delivering humidity and temperature data serially. It measures relative humidity from 20% to 90% RH and temperature from 0°C to 50°C. The DHT11 has four pins: two for power supply, one unused, and one data pin for communication. Data …
PIR Motion Sensor A PIR (Passive Infrared) sensor detects infrared radiation emitted by living objects, allowing it to sense their presence. The sensor is divided into two slots, both connected to a differential amplifier. When a stationary object is in front of the sensor, both slots receive equal radiation, resulting in zero output. However, when …
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Small DC Motor Small DC motor A DC motor converts electrical energy, provided as Direct Current (DC), into mechanical energy. In the case of a DC motor, this mechanical energy is seen as the rotational movement of the motor shaft. By reversing the direction of the DC current through the motor, the shaft’s rotation direction …
Stepper Motor Stepper Motor A stepper motor is a brushless DC motor that divides a full 360° rotation into a series of equal steps. The motor rotates by following a specific sequence of control signals, and its speed can be adjusted by changing the rate of these signals. Stepper motors come in a variety of …
Introduction The Global Positioning System (GPS) uses signals from satellites in space and ground stations on Earth to accurately determine a location. GPS receives Radio Frequency signals sent by satellites and ground stations, which it uses to calculate its exact position. GPS itself does not transmit any information. The received signals contain timestamps indicating when …
4×4 Keypad Introduction A keypad serves as an input device, detecting and processing key presses from the user. A 4×4 keypad comprises 4 rows and 4 columns, with switches positioned at each intersection. Pressing a key connects a specific row and column, allowing the system to recognize the pressed key. To detect a keypress, configure …
