Wireless communication system circuit module design circuit diagram based on nRF401

This design is based on nRF401 as the wireless transceiver chip and two AT89C2051 as the control chip to design a wireless communication system. One piece of AT89C2051 (defined as control chip A) controls nRF401. The IO interface of AT89C2051 cooperates with the serial port to control nRF401 to achieve asynchronous communication; the other AT89C2051 (defined as control chip B) can not only meet the requirements of the bus serial port, but also solve the problem of control chip A. Due to frequent serial interruptions and the inability to respond to the bus in time, it plays the role of sharing tasks, isolating interference, and expanding the serial port. Using the design method of two 2051 microcontrollers, compared with the design of one dual serial port microcontroller, can reduce costs, improve chip utilization, and isolate interference. Practice shows that the system has a simple structure and strong anti-interference ability, and can well solve the wireless communication problems between short-distance systems.

nRF401 is a single-chip UHF wireless transceiver chip developed by Nordic Company, working in the 433MHz ISM band. In the receiving mode, nRF401 is configured as a traditional heterodyne receiver. The received RF modulated digital signal is amplified by a low-noise amplifier, converted into an intermediate frequency by a mixer, amplified and filtered, and then entered into the demodulator. After demodulation, it is converted into digital signal output (DOUT terminal). In the transmit mode, the digital signal is input through the DIN terminal, processed by the phase-locked loop and the voltage-controlled oscillator, and then enters the RF output of the power amplifier. In the design of this system, in order to avoid interference, the wireless transceiver part based on nRF401 is built on a separate PCB board, and the communication control interface (J1) is led out to form an independent wireless transceiver module.