Wireless modules are widely used in vehicle monitoring, remote control, telemetry, small wireless networks, wireless meter reading, access control systems, community paging, industrial data acquisition systems, wireless tags, identification, non-contact RF smart cards, small wireless data terminals, safety and fire protection System, wireless remote control system, biological signal collection, hydrometeorological monitoring, robot control, wireless 232 data communication, wireless 485/422 data communication, digital audio, digital image transmission and other fields.
Technical indicators of superheterodyne receiving module: Volume of superheterodyne receiving module: 28x11x4.5mm. Main technical indicators: 1. Communication method: AM 2. Working frequency: 315MHZ3. Receiving sensitivity: -102DBM4. Quiescent current: 0.1MA5. Working current : 2.5MA6, working voltage: DC 2.1-5.5V7, output mode: TTL level.
1. When the transmitting and receiving modules are connected to the antenna, it is best to use a 25 cm long wire, and it is best to be erected for long-distance transmission.
2. The working voltage of the transmitting module: DC 3～12V; the working voltage of the receiving module: DC 5V, the output mode: TTL level.
3. The TTL level signal is used most often because the data representation adopts binary regulations. +5V is equivalent to logic "1", and 0V is equivalent to logic "0". This is called TTL (transistor-transistor logic level). )signal system.
4. The encoding signal sent by the encoding chip PT2262 is composed of address code, data code, and synchronization code to form a complete code word. After the decoding chip PT2272 receives the signal, the address code is checked twice before the VT pin outputs high voltage. level.
5. PT2262/2272 can have up to 12 bits (A0-A11) three-state address terminal pins (floating, connected to high level, connected to low level), any combination can provide 531441 kinds of address codes, PT2262/2272 can have up to 6-bit (D0-D5) data terminal pins, only the address codes of the transmitting terminal PT2262 and the receiving terminal PT2272 are exactly the same, they can be paired.
6. Both address code and data code are represented by pulses with different widths. Two narrow pulses represent "0"; two wide pulses represent "1"; one narrow pulse and one wide pulse represent "F", which is the address code. "Hanging".
7. The oscillating resistance must also be matched, otherwise the receiving distance will become close or even unable to receive.
8. The PT2272 decoder chip has different suffixes, indicating different functions, such as L4/M4/L6/M6