Practical Arduino: Utilizing the 433MHz Wireless Transmitter and Receiver Module

Experiment: 433M Wireless Transmitting and Receiving Module, Super Regenerative Anti-Theft Wireless Alarm Module

Regenerative receivers amplify signals using positive feedback in a loop without frequency conversion, providing simple, sensitive, compact, and inexpensive designs. Drawbacks may include unstable sensitivity, poor selectivity, and low interference resistance. Unlike superheterodyne receivers, which convert signal frequencies, regenerative receivers process signals directly.

Compared to superheterodyne technology, regenerative receivers have several advantages:

1. Simple circuitry, with the most basic receiver requiring only one transistor to perform functions such as amplification, detection, and power amplification.
2. High sensitivity.
3. Compact size and low cost.

The main disadvantages of regenerative receivers are:

1. Unstable sensitivity across the full frequency spectrum, making them more suitable for fixed-frequency applications.
2. Poor selectivity and interference rejection capabilities.
3. Poor frequency stability, leading to frequency drift.
4. Susceptibility to blocking when receiving signals at close range.

433MHz wireless module

The 433MHz wireless module, The RF433 RF small module, utilizing high-frequency RF technology, is a miniature transceiver with an all-digital single IC RF front-end and an ATMEL AVR microcontroller. It supports high-speed data signal transmission, packaging, error checking, and correction for wireless data transmission. Industrial-grade components ensure stable and reliable operation, with a compact size for easy installation. It is widely used in security alarms, wireless automatic meter reading, home and industrial automation, remote control, and wireless data transmission.

Transmitter module

1. Communication method: Amplitude Modulation (AM)
2. Operating frequency: 315MHz/433MHz
3. Frequency stability: ±75kHz
4. Transmitting power: ≤500mW
5. Static current: ≤0.1μA
6. Transmitting current: 3-50mA
7. Operating voltage: DC 3-12V
8. Transmitter head (utilizing 2SC3357 transistor)

Ideal for wireless remote control and data transmission systems with multiple transmitters and a single receiver. SAW resonators offer excellent frequency stability, comparable to crystals, surpassing common LC oscillators. Even with high-quality variable capacitors, maintaining tuned frequency against temperature and vibration changes is challenging. The transmitter module lacks an integrated encoding circuit but features a data modulation transistor Q1, allowing for straightforward integration with external encoding circuits, rolling code circuits, and microcontrollers, regardless of encoding circuit voltage or output signal amplitude. For instance, when interfacing with encoding ICs such as PT2262 or SM5262, simply connect the data output pin (Pin 17) to the data module's input terminal.

The transmission module operates between 3 to 12V, maintaining a stable frequency regardless of voltage changes. Its paired receiver can receive signals without adjustments. At 3V, the module transmits up to 20-50 meters; at 5V, the range is 100-200 meters; at 9V, it extends to 300-500 meters. Optimal performance is at 12V, with a transmission current of 60mA and a range of 700-800 meters at 500mW. Beyond 12V, power consumption rises without significant improvement in transmission range.

This module offers high transmission power and long range, ideal for challenging environments. A 25cm wire is recommended for the antenna. For optimal long-distance communication, position the antenna vertically. Keep in mind that actual transmission distances are typically half or less than the rated distance, so account for this in development.

The data module uses ASK modulation for lower power consumption, with transmission current dropping to zero when the data signal is inactive. Connect the data signal to the transmission module's input using resistors or direct connections, avoiding capacitive coupling to ensure proper function. Maintain the data voltage level near the module's operating voltage for optimal modulation.

The transmission module should be mounted vertically on the motherboard's edge, at least 5mm from other components to prevent impedance issues. Its range depends on signal frequency, amplitude, voltage, battery capacity, antenna, receiver sensitivity, and environment. In open areas, it can reach up to 800 meters, but obstacles reduce this distance. Signal refraction and reflection cause dead zones and instability, resulting in variable distances based on conditions.

Super-regenerative Receiver Module

Dimensions: 30x13x8 millimeters

Main Technical Specifications:

1. Communication Method: Amplitude Modulation (AM)
2. Operating Frequency: 315MHz/433MHz
3. Frequency Stability: ±200kHz
4. Receiver Sensitivity: -106dBm
5. Static Current: ≤5mA
6. Operating Current: ≤5mA
7. Operating Voltage: DC 5V
8. Output Method: TTL Level

The receiver module operates at 5V and 4mA, featuring a super-regenerative circuit with -105dBm sensitivity. A 25-30cm vertical wire is recommended for reception. The module lacks a decoding IC and functions as a basic component, achieving its full potential when integrated into specific circuits and further developed. This design allows for adaptable use with various decoding circuits or microcontrollers, offering convenience and flexibility in circuit design.

The advantages of this circuit include:

1. The antenna input end features a selective frequency circuit, independent of the quarter-wavelength antenna's selective function. When controlling over shorter distances, the external antenna can be shortened or even removed.
2. The waveform at the output end is clean without signals, with interference signals appearing as brief spike pulses rather than the dense noise waveforms produced by other super-regenerative receiving circuits, resulting in strong anti-interference capabilities.
3. The module itself emits minimal radiation, and combined with the shielding effect of the copper foil grounding mesh on the back of the circuit board, leakage from self-oscillation and intrusion of external interference signals are minimized.
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Using a skeleton-core copper inductor to set the frequency at 315MHz before sealing enhances stability over circuits with adjustable capacitors. Adjustable capacitors have limited precision and cannot be sealed post-adjustment, as they are prone to changes from environmental factors. Adjustable inductors, however, allow for precise multi-turn adjustments and can be sealed to maintain constant inductance.

433M Wireless Transmitting and Receiving Module

The transmitting module can pair with various receiving modules and our store's wireless receivers. It offers stable modulation, reliable performance, a wide voltage range, consistent quality, and good value. The super-regenerative module features an LC circuit with amplification and shaping, outputting TTL level signals for direct decoder connection, providing convenience and affordability. It has a wide bandwidth, typically ±10MHz, with default frequencies at 315MHz or 433.92MHz, and can adjust between 266MHz to 433MHz if needed.

Module Applications

Remote control switches, receiving modules, motorcycles, car anti-theft products, home security products, electric gates, roller shutters, windows, remote control sockets, remote-controlled LEDs, remote-controlled stereos, remote-controlled garage doors, remote-controlled sliding doors, remote-controlled rolling shutters, sliding gates, remote-controlled door opening systems, remote-controlled curtains, alarm hosts, alarms, remote-controlled motorcycles, remote-controlled electric vehicles, remote-controlled MP3 players, and more.

Usage Notes

1. The VCC voltage should be consistent with the module's operating voltage, and power filtering should be done effectively.
2. The antenna greatly affects the reception of the module. It is advisable to connect a 1/4 wavelength antenna, typically using a 50-ohm single-core wire, with the antenna length for 433M being approximately 17cm.
3. The position of the antenna also influences the module's reception. During installation, extend the antenna as straight as possible, away from shielding bodies, high-voltage areas, and sources of interference. When in use, the receiving frequency, decoding method, and oscillation resistance should match that of the transmitter.
4. Both the transmitting and receiving modules require external antennas; otherwise, the signal distance will only be a few centimeters.

TAG：433m wireless module,Transmitter and Receiver Module,Electronics product design