With the rapid development of modern communication technology, near-field communication technology presents a good development momentum. More and more people are beginning to pay attention to it.
Wireless Remote Control Topic Report Part I: Design Background and Objectives
Design background:
With the progress of science and technology and the development of society, the design of modern electronic products pays more and more attention to the simplicity and practicality of products. The fast-paced modern life makes many electronic products small, convenient and simple. To meet this demand. A wireless remote control system was born.
Its appearance has brought great convenience to people in industry, agriculture, aerospace and family life, enabling people to control the normal operation of other machines and systems within a certain distance. It has brought convenience to the development of industry. He is the inevitable trend of the future development of the electronic industry. In the past industrial production, whether to start the machine or shut down the system.
All of them are controlled by wire, and people need to go to the control center for manual operation in person. It limits the progress of industrial production and the improvement of production efficiency. With the continuous progress of science and technology, this control will be replaced by advanced control. Therefore, the appearance of remote control system has brought a new revolution to industry.
It has greatly promoted the controlled production of industry. It enables people to control other machines within a certain distance, even in the distant universe. The operation of the system greatly improves the production efficiency, makes a great contribution to the improvement of economy, and also determines a country's position in the world. Therefore, as a builder of the country's future. It is necessary for us to learn remote control knowledge well, and it is also the demand of the country and the times. Design objectives:
1. The control distance shall be at least 20m.
2. The switch can be controlled by different keys. 3. The switch can be opened, closed and delayed.
Design ideas and technical routes
In this design, 3 15MHz frequency-stabilized radio remote control module and other peripheral components are used to assemble the remote control switch. Through the single chip microcomputer, all kinds of electrical appliances above 220V can be controlled.
The transmitting circuit scans the key position of the keyboard, and the corresponding control signal is sent to the data input end of PT2262 by the single chip microcomputer. It is coded and modulated by PT2262 on the carrier wave of 3 15MHZ, amplified by the first-stage high frequency and then emitted by the antenna.
Then the signal is received by the receiving board, and the modulated signal is demodulated by the detection circuit after two-stage high-frequency amplification. The digital signal is amplified by LM358, a two-stage high-gain amplification block, and then sent to PT2272 for decoding, and the output end is sent to the single chip microcomputer, which controls the control relays of the corresponding appliances respectively according to the action signals. Complete the control of electrical appliances.
Launching part: 3 15M
wireless transmitting module
Receiving module: 3 15M wireless receiving module.
Design progress plan
1, 20 14, 65438+February? 20 15 1 graduation thesis topic, meet with the tutor.
2.20 15 1 month? 20 15 10 collect relevant information and establish a framework.
3. 20 15 1 graduation thesis opening defense.
4.2065438+February 2005? On March 20 15, Protel software was used to draw the circuits of each part, and the single-chip computer program was written.
5.2065438+March 2005? 2065438+April 2005 Monitor and adjust the circuit.
June, 2065438+May 2005? 2065438+May 2005 Optimize the program and write a paper.
7.2065438+May 2, 2005? 201May 5, 1 1, I finished my thesis and defended my graduation thesis.
Opening report on the design of multi-purpose intelligent remote control switch Part II: 1. The purpose and significance of the research.
Remote control switch is an indispensable development in the era of intelligent control, which brings a lot of convenience and quickness to our life. If you use smart switches in your home, you can control lights, electrical appliances, curtains and door locks, and enjoy the remote control of smart homes anytime and anywhere, so that intelligence and fashion can be perfectly combined.
Commonly used remote controllers can be roughly divided into two categories: infrared remote controllers and radio remote controllers.
The infrared remote control system people see is divided into two parts: transmitting and receiving. The emitting element of the emitting part is an infrared light emitting diode, which emits infrared light instead of visible light. The infrared wavelength emitted by commonly used infrared light-emitting diodes is about 940nm, and its appearance is similar to that of ordinary ones. The 5mm led is the same, but the color is different. The emission power of a single infrared LED is about 100mW. The infrared receiving tube of the receiving circuit is a photosensitive diode. When in use, it needs reverse bias to work normally and obtain high sensitivity. Generally, there are two kinds of infrared receiving diodes: round and square. Due to the low emission power of infrared light emitting diode and the weak signal received by infrared receiving diode, a high gain amplifier circuit should be added at the receiving end. However, nowadays, whether it is amateur production or regular products, radio remote control is a remote control device that uses radio signals to control various mechanisms in the distance.
The (1) transmitting circuit is provided by 3V power supply, and the carrier formation of 40KHZ low-frequency signal is realized by NAND gate and external components, with high stability. This part of the circuit adopts NAND gate integrated circuit.
(2) The receiver circuit consists of several parts. LM567 integrated block is used to realize the encryption function of PLL, bistable circuit is used to control relay, and the switch of relay is used to control load.
Radio remote control system is generally divided into two parts: transmitting and receiving. The transmitter mainly includes coding circuit and transmitting circuit.
Road. The coding circuit is controlled by an operation switch, and the operation switch enables the coding circuit to generate required control instructions. The command signals generated by the coding circuit are all low-frequency electrical signals, which cannot be directly transmitted to the remote control target. Before being transmitted by the transmitting antenna, the command signal must be sent to the transmitting circuit to be transmitted on the high frequency carrier. The receiver consists of a receiving circuit and a decoding circuit. The signal sent by the receiving antenna is selected and amplified by the high frequency part of the receiver and sent to the demodulator. The function of the demodulator is to unload the command signal from the carrier. Because the unloaded instruction signals are mixed, they are sent to the decoding circuit for decoding to recover the instruction signals.
Radio remote control is a remote control device that uses radio signals to control various mechanisms in the distance. Radio remote control system is generally divided into two parts: transmitting and receiving. The transmitter mainly includes coding circuit and transmitting circuit. The coding circuit is controlled by an operation switch, and the operation switch enables the coding circuit to generate required control instructions. The command signals generated by the coding circuit are all low-frequency electrical signals, which cannot be directly transmitted to the remote control target. Before being transmitted by the transmitting antenna, the command signal must be sent to the transmitting circuit to be transmitted on the high frequency carrier. The receiver consists of a receiving circuit and a decoding circuit. The signal sent by the receiving antenna is selected and amplified by the high frequency part of the receiver and sent to the demodulator. The function of the demodulator is to unload the command signal from the carrier. Because the unloaded instruction signals are mixed, they are sent to the decoding circuit for decoding to recover the instruction signals.
A wireless remote control multi-way switch system is designed and manufactured by using wireless transmitter chip Si40 10, wireless receiver chip Si43 13 and single chip computer C805 1F920 developed by Silicon Laboratory. It is simple in structure, stable in performance, convenient to control, suitable for occasions where there are many controlled appliances, and can realize multi-channel and multi-function control.
The radio remote control multiplex switch system consists of two parts: radio transmitting circuit and radio receiving control circuit.
Infrared remote controller is not very effective because of the influence of remote control distance and angle. If the code is transmitted and received by FM or AM, the remote control distance can be increased, which is not affected by the angle. The infrared remote control transmitting and receiving module can be used for indoor infrared remote control without affecting the surrounding environment and interfering with other electrical equipment. Because you can't go through the wall, the household appliances in different rooms can use the universal remote control without interfering with each other; The circuit debugging is simple, as long as the given circuit is connected correctly, it can be put into operation without any debugging; Easy coding and decoding, multi-channel remote control. Compared with wired remote control, wireless remote control is not affected by distance, which completely eliminates the hidden dangers brought by towing cable remote control device and brings more convenience to people's daily work and life.
With the rapid development of digital processing technology, wireless digital communication technology is becoming more and more mature, with strong anti-interference ability and easy to process digital signals, which makes the anti-interference performance of wireless remote control system gradually improve and the safety performance greatly improve.
Compared with ultrasonic remote control and infrared remote control, radio remote control is based on the propagation of radio signals in the air. According to the frequency of radio waves, it can penetrate certain obstacles and spread over a long distance, so it has become the first choice in the field of wireless remote control and has been widely used in national defense, military, scientific research and daily work and life.
2. The main content of the study.
Design a radio remote control switch, which requires
The transmitting frequency of (1) remote control switch is 2.4GHZ.
(2) The remote control distance is about 10m, which is mainly used to remotely control the switch of home appliances.
(3) The transmitter power supply voltage should be lower than 10V.
(4) The remote control receiver is required to accurately receive the carrier frequency signal of 2.4GHZ and demodulate the signal to control the switching action of household appliances.
(5) The whole remote control circuit is as simple and feasible as possible.
3. Research methods
3. 1 2.4GHZ wireless remote controller:
Wireless remote control is to control the model by using high frequency radio waves. At present, the traditional wireless remote control system generally has two major problems: co-frequency interference and short remote control distance. The main reason is that the bandwidth is narrow due to the lower carrier frequency, and the possibility of co-frequency interference is increased due to the transmission of control information in analog mode. Using advanced 2.4 GHz spread spectrum technology, theoretically, hundreds of people can remotely control their own models in the same place without interference, and it also has advantages in remote control distance. The power of 2.4 GHz remote control system is only below 100 mW, while its remote control distance can reach above 1, and the antenna length is only 3 cm due to high frequency. In addition, there are many commercial technologies for reference. Therefore, it is necessary to apply 2.4 GHz spread spectrum communication technology to the field of wireless remote control.
3.2 2.4G wireless module:
3. 2. 1 NRF 24 e 1 wireless chip module
The main control chip of the remote controller is nRF24LE 1 made by Norway Nordic Company, which is divided into two parts: enhanced 805 1MCU and embedded 2.4G low-power wireless transceiver core NRF 24L01P. There are three options for air speed: 250 kbps, 1 Mbps and 2 Mbps, which ensures the rapid transmission of air data. They communicate with each other through SPI interface. It also has rich peripheral resources, especially the built-in 128-bit AES hardware encryptor, which can encrypt any wireless data with high intensity, ensuring the security of wireless data, especially meeting the requirements of RFID for high security. The working mode of CPU can be controlled by the control bit of the switch status register. When working in the transmitting mode, the transmitting power is -6dBm, the current consumption is 9mA, and the receiving mode is 12.3mA, which provides innate conditions for designing a low-power system.
The internal structure of NRF 24U 1 chip is basically the same as that of NRF 24U 1. Considering the cost calculation, the NRF 24u 1+ device controller conforming to the full-speed USB 2.0 standard is adopted.
3.2.2 JTT-24L0 1+ embedded micro-power wireless data transmission module
JTT-24L0 1+ is a single-chip micro-power wireless transceiver module working in the general ISM frequency band of 2.4~2.5GHz, and it is a wireless communication module developed by Chengdu Jiangteng Technology Co., Ltd. by using high-performance wireless RF chips nRF24L0 1+ and high-precision peripheral components.
Features:
(1) Built-in 2.4Ghz antenna, compact size15 mm x 24 mm.
(2) The transmission distance is long, and the interference-free sight distance in the open field is 100m, and the specific distance depends on the environment.
(3) Using real GFSK single transceiver chip.
(License-free use of the 2.4 GHz global open ISM band.
(5) Automatic response and automatic forwarding function
(6) Address and CRC check function and point-to-multipoint communication address control
(7) The highest working speed is 2Mbps, with high efficiency GFSK modulation and strong anti-interference ability, which is especially suitable for industrial control field and can transmit audio and video.
(8) The standard inclination spacing interface is convenient for embedded application.
(9) The data rate of SPI interface is 0~ 10Mbps.
(10) 125 optional working channel to meet the needs of multipoint communication and frequency hopping communication.
(1 1) supports wireless wake-up, and the short message channel switching time can be used for frequency hopping.
(12) adopts 10PPM high-precision crystal oscillator.
Inductance and capacitance in (13) high Q 0402 package.
(14) The working voltage 1.9~3.6V is recommended, but it should not exceed 3.6V. The voltage should be as close as possible to 3.6V but not exceed 3.6V..
3.2.3 2.4G JF24D wireless transceiver module
JF24D integrates the functions of high frequency keying (GFSK) transceiver circuit, and realizes the function of high-speed data transmission with a very small volume. JF24D has a transmission rate of 1Mbps and a fast frequency hopping check function, which can realize stable and reliable short-distance data transmission in crowded ISM frequency bands. ISM band license for global work.
Features:
(1) Low pressure and high efficiency
(2) Low cost and bidirectional high-speed data transmission.
(3) Small size (no need for external antenna)
(4) It has the functions of fast frequency hopping, forward error correction and verification.
This topic plans to adopt JF24D wireless transceiver module.
3.3 Realization of Multi-channel Remote Control
(1) 5 1 series single chip microcomputer (AT89S5 1) is used for software programming, signal coding and decoding is completed, and multi-channel remote control is realized.
(2) Using the coding and decoding chip of wireless remote controller to complete the coding and decoding of signals and realize multi-channel remote control. Such as: EV 1527, PT 2262, PT 2294-M4, PT 2264, etc.
Although there are many ways to realize this design, I think it is better to use JF24C wireless transceiver module and single chip microcomputer to complete it. The following is the research method I decided:
JF24D is connected with single chip microcomputer through SPI digital interface. It supports SPI standard format (CKPHA=0).
Note: JF24C can be equipped with various single-chip computers. For single chip microcomputer without SPI in hardware, I/O port or serial port can be used to simulate SPI. When matched with 5 1 series single chip microcomputer, P0 port is added with a 10K pull-up resistor, and other IO ports can be directly connected with JF24C. Single chip microcomputer can supply power at 5V, JF24C can supply power at 3.3V, and the working voltage of JF24C cannot exceed 3.5V, otherwise the device will be damaged.
4. Implementation plan
The seventh semester:
Week 8: Choose the graduation project. Complete the determination of the instructor and graduation project.
Week 9-12: complete the opening report and foreign language translation.
Week 12: finish the opening defense of graduation project.
Week 13-20: According to the proposed project implementation plan, conduct in-depth research and basically complete the hardware or software design related to graduation design.
Week 2/kloc-0: under the guidance of the teacher, complete the overall scheme design, system software and hardware design, experimental testing and other related aspects for in-depth research.
The eighth semester:
Week 65438 +0-5: Continue to complete the thesis design.
Week 6- 9: Submit the first draft of graduation design/thesis to the tutor, and revise the first draft according to the guidance.
Week 10- 14: Finish the graduation thesis and review its format.
Week 15: graduation defense.
5. References:
Chen Yongfu. Practical radio remote control circuit. Beijing: People's Posts and Telecommunications Publishing House, 2007.
Zhu Weihua, Michael Chen. High frequency electronic circuit. Beijing: Electronic Industry Press, 2003.
[3] Huang Zhiwei and Yan Wang. National electronic competition training course for college students. Beijing: Electronic Industry Press, 2005.
[4] Huang Zhiwei. Design of the National Electronic Design Competition for College Students. Beijing: Beijing University of Aeronautics and Astronautics Press, 2006.
[5] tavares and Jose. Mendes. Household remote control switch board. University of Minio, Portugal.
Instructor's opinion
Instructor's signature:
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