A radio frequency transceiver for short-range information transmission

Abstract

A radio frequency transceiver for short-range information transmission includes a microcontroller and a TDA5255 RF chip. The microcontroller and TDA5255 RF chip have seven circuit lines: power line, ground line, BUSCLK line, BUSDATA line, Rx / Tx line, DATA line, and PWD / DD line. The BUSCLK line and BUSDATA line are the bus clock line and bus data line, respectively. This RF transceiver enables short-range information transmission and can send arbitrary information from a PC via connection. It can also display the received feedback information on a host computer interface. The system has been applied to the controller of an electric vehicle with good control performance. It can also be ported as a module for short-range remote control applications.

Description

Technical Field

[0001] This utility model belongs to the field of mobile communication technology and is a design for realizing a short-range information transmission method. Background Technology

[0002] Short-range wireless data communication, as a type of wireless access communication, is widely used in remote control, alarm, telemetry, and other fields. Designing an RF transceiver is an important method for achieving short-range information transmission. This design utilizes Infineon's TDA5255 RF transceiver chip and XC866 microcontroller to design an RF transceiver and achieve information transmission.

[0003] The TDA5255 RF chip is a low-power, monolithic FSK / ASK transceiver suitable for half-duplex, low-data-rate communication in the 433MHz–435MHz range. This device features high integration and a simple peripheral circuitry. Internally, it includes a power amplifier, low-noise amplifier, AGC control circuitry, a double-balanced mixer, a synthesized converter, an I / Q limiter, an RRSI generator, an FSK demodulator, a fully integrated VCO and PLL synthesizer, an adjustable crystal oscillator, a data filter, a data comparator, positive and negative peak detectors, a data rate detection circuit, and a bus interface. It also offers a low-power mode with low current consumption (9mA in receive mode, 12mA in transmit mode), a power supply voltage of 2.1V–5V, FSK / ASK modulation and demodulation, an I2C / 3-wire microcontroller interface, and internal low-pass channel selection and data filters with adjustable bandwidth. The data limiter has a self-adjusting threshold. The FSK receiver sensitivity is -109dBm, the transmit power is +13dBm, and the maximum data rate is up to 100kb / s. The TDA5255 RF chip's basic operating modes include: transmit / receive mode, ASK / FSK modulation, and high transmit power / low transmit power mode, which can be controlled via the corresponding pins Rx / Tx, ASK / FSK, and PWD / DD. It can be used in low data rate communication systems, wireless access systems, remote control systems, alarm systems, telemetry systems, home automation systems, etc.

[0004] The microcontroller used is the Infineon XC866 8-bit microcontroller. The XC866 is designed based on the XC800 core, which is compatible with the standard 8051 processor. Utility Model Content

[0005] The purpose of this invention is to provide a radio frequency transceiver for short-range information transmission, which solves the problems existing in the prior art.

[0006] The technical solution adopted by this utility model to solve its technical problem is:

[0007] 1. A radio frequency transceiver for short-range information transmission, characterized in that: it includes a microcontroller and a TDA5255 radio frequency chip, wherein the microcontroller and the TDA5255 radio frequency chip are provided with 7 circuit lines, namely a power line, a ground line, a BUSCLK line, a BUSDATA line, an Rx / Tx line, a DATA line, and a PWD / DD line; wherein: the BUSCLK line and the BUSDATA line are the bus clock line and the bus data line, respectively;

[0008] When BUSMODE=0, the bus mode of the TDA5255 RF chip is I2C, and the microcontroller sets the working mode of the TDA5255 RF chip through the I2C bus.

[0009] When the Rx / Tx pin is floating or high, the TDA5255 RF chip is in transmit mode; the RF signal travels from the antenna through capacitors C6, C8, and C9, inductor L1, and capacitor C11 to the low-noise amplifier input pin; resistor R9 is high impedance, and capacitor C6 is a DC decoupling capacitor.

[0010] The Rx / Tx pin can be grounded or programmed to put the device in receive mode; the Rx / Tx pin operates in open-drain mode, outputs logic low, and has low resistance to resistor RF; DC current flows from VCC through L2, inductors L3, D2, R9, and D1 to GND.

[0011] This utility model also has the following additional technical features:

[0012] As a further specific optimization of the technical solution of this utility model: the PWD / DD pin is used to set the high and low power consumption modes of the RF device; the DATA pin is a data pin. In the transmit mode, the microcontroller sends a signal to the RF device; in the receive mode, if a signal is received, the waveform of this pin is the same as that of the transmitter, and the test delay is 25μs; when no signal is received, this pin outputs irregular pulse noise.

[0013] As a further specific optimization of the technical solution of this utility model: the synchronous serial channel (SSC) of the microcontroller XC866 supports full-duplex and half-duplex synchronous communication.

[0014] As a further specific optimization of the technical solution of this utility model: the microcontroller sends and receives data through the TXD and RXD lines, which are usually connected to the pins MTSR (master transmit / slave receive) and MRST (master receive / slave transmit) respectively; the clock signal is output from MS_CLK (master serial shift clock) or input from SS_CLK (slave serial shift clock), which are usually connected to the pin SCLK.

[0015] As a further specific optimization of the technical solution of this utility model: both the sending and receiving of microcontroller data have buffer registers; when transmitting information with the TDA5255 RF chip, a half-duplex communication mode is used, and the internal register values ​​of the TDA5255 RF chip are set through the I2C bus protocol.

[0016] As a further specific optimization of the technical solution of this utility model: the microcontroller completes the working mode setting of the TDA5255 RF chip, controls the TDA5255 RF chip to send valid information, receives and processes the data received by the TDA5255 RF chip, etc.; P1.0 and P1.1 are connected to RXD0 and TXD0 of MAX3232 respectively to complete serial communication with the PC.

[0017] Compared with the prior art, the advantages of this utility model are:

[0018] This invention relates to a radio frequency transceiver capable of short-range information transmission. It can send arbitrary information from a PC via a connection and display the received feedback information on a host computer interface. The system has been applied to the controller of an electric vehicle, demonstrating excellent control performance. It can also be ported as a module for applications such as short-range remote control. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the radio frequency transceiver circuit of this utility model;

[0020] Figure 2 This is a schematic diagram of the microcontroller program flow of this utility model;

[0021] Figure 3 This is a schematic diagram of the information transmission method of this utility model. Detailed Implementation

[0022] Exemplary embodiments of the present invention will now be described in more detail with reference to the accompanying drawings.

[0023] Example 1

[0024] Hardware circuit design for a radio frequency transceiver to achieve short-range information transmission, such as... Figure 1 As shown. The microcontroller and TDA5255 RF chip have 7 circuit lines: power line, ground line, BUSCLK line, BUSDATA line, Rx / Tx line, DATA line, and PWD / DD line.

[0025] When BUSMODE=0, the TDA5255 RF chip operates in I2C mode. The microcontroller sets the operating mode of the TDA5255 RF chip via the I2C bus. The BUSCLK line and BUSDATA line are the bus clock line and bus data line, respectively.

[0026] When the Rx / Tx pin is floating or high, the TDA5255 RF chip is in transmit mode. At this time, the RF signal travels from the antenna through capacitors C6, C8, C9, inductor L1, and capacitor C11 to the low-noise amplifier input pin. Resistor R9 is high impedance and does not affect circuit matching. Capacitor C6 is a DC decoupling capacitor. The other input signal of the differential low-noise amplifier can be AC ​​coupled through a large capacitor. In this case, the differential low-noise amplifier functions as a more easily matched single-ended low-noise amplifier. Important matching components include C8, C9, inductor L1, and capacitor C11.

[0027] The Rx / Tx pins can be grounded or programmed to put the device in receive mode. In this state, the Rx / Tx pins operate in open-drain mode, outputting logic low with low impedance to resistor RF. DC current flows from VCC through L2, inductor L3, D2, R9, and D1 to GND. Because R9 has high impedance, capacitors C6, C4, and C5 have large capacitance values. This simplifies the RF signal. The low-noise amplifier RF is grounded, so there is no power consumption at the low-noise amplifier input. Power amplifier matching primarily depends on C8, capacitor C28, inductor L2, capacitor C29, and inductor L3. It is important to note that capacitor C8 cannot be modified during power amplifier matching design, as its value is already determined by the low-noise amplifier input matching. For accurate calculation of external capacitance, the capacitance on the pads and the parasitic capacitance between the pins and the switches (C20, C22, C23) must be considered.

[0028] The PWD / DD pins are used to set the high and low power modes of the RF device. The DATA pin is the data pin. In transmit mode, the microcontroller sends signals to the RF device. In receive mode, if a signal is received, the waveform on this pin is the same as the transmitter, with a test delay of 25μs. When no signal is received, this pin outputs irregular pulse noise. In practical applications, the noise can be removed by modifying the RSSI signal threshold value of the TDA5255 RF chip, allowing the DATA pin to remain low when no valid information is received.

[0029] Example 2

[0030] Microcontroller design for a radio frequency transceiver to achieve short-range information transmission:

[0031] The XC866's Synchronous Serial Channel (SSC) supports full-duplex and half-duplex synchronous communication. Data is sent and received via the TXD and RXD lines, typically connected to the MTSR (Master Transmit / Slave Receive) and MRST (Master Receive / Slave Transmit) pins, respectively. The clock signal is output from MS_CLK (Master Serial Shift Clock) or input from SS_CLK (Slave Serial Shift Clock), these two clock lines are typically connected to the SCLK pin. Both data transmission and reception are buffered by registers. Half-duplex communication is used when transmitting information with the TDA5255 RF chip, and the internal register values ​​of the TDA5255 RF chip are set via the I2C bus protocol.

[0032] The microcontroller sets the operating mode of the TDA5255 RF chip, controls the TDA5255 RF chip to send valid information, and receives and processes the data received by the TDA5255 RF chip. P1.0 and P1.1 are connected to RXD0 and TXD0 of the MAX3232 respectively to complete serial communication with the PC.

[0033] Example 3

[0034] The software design of an RF transceiver for short-range information transmission is shown in the following flowchart. Figure 2 As shown in the diagram, the design of a radio frequency transceiver for short-range information transmission is illustrated. Figure 3 As shown.

[0035] Data is transmitted by first sending a "0", then a "1", followed by the information bit "0" or "1". This way, the information code is obtained after a 1.5-basic-time delay following the rising edge. For example... Figure 3 As shown. The definition of the basic time determines the information transmission rate. Here, it is taken as 100μs. One information code is transmitted every 300μs, and the transmission rate is 3.3kb / s. The maximum data rate of the TDA5255 RF chip can reach 100kb / s.

[0036] The above detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

Claims

1. A radio frequency transceiver implementing a near field communication transmission mode, characterized by: It includes a microcontroller and a TDA5255 RF chip. The microcontroller and the TDA5255 RF chip are equipped with 7 circuit lines, namely power line, ground line, BUSCLK line, BUSDATA line, Rx / Tx line, DATA line, and PWD / DD line; among which, the BUSCLK line and BUSDATA line are the bus clock line and the bus data line, respectively. When BUSMODE=0, the bus mode of the TDA5255 RF chip is I2C, and the microcontroller sets the working mode of the TDA5255 RF chip through the I2C bus. When the Rx / Tx pin is floating or high, the TDA5255 RF chip is in transmit mode; the RF signal travels from the antenna through capacitors C6, C8, and C9, inductor L1, and capacitor C11 to the low-noise amplifier input pin; resistor R9 is high impedance, and capacitor C6 is a DC decoupling capacitor. The Rx / Tx pin can be grounded or programmed to put the device in receive mode; the Rx / Tx pin operates in open-drain mode, outputs logic low, and has low resistance to resistor RF; DC current flows from VCC through L2, inductors L3, D2, R9, and D1 to GND.

2. The radio frequency transceiver for implementing near field information transmission according to claim 1, wherein: The PWD / DD pins are used to set the high and low power modes of the RF device; the DATA pin is the data pin. In transmit mode, the microcontroller sends signals to the RF device; in receive mode, if a signal is received, the waveform on this pin is the same as that on the transmitter, with a test delay of 25μs; when no signal is received, this pin outputs irregular pulse noise.

3. The radio frequency transceiver for realizing short-range information transmission according to claim 1, characterized in that: The XC866 microcontroller's Synchronous Serial Channel (SSC) supports full-duplex and half-duplex synchronous communication.

4. The radio frequency transceiver for realizing short-range information transmission according to claim 1, characterized in that: The microcontroller sends and receives data via the TXD and RXD lines, which are typically connected to the MTSR (Master Transmit / Slave Receive) and MRST (Master Receive / Slave Transmit) pins, respectively. The clock signal is output from MS_CLK (Master Serial Shift Clock) or input from SS_CLK (Slave Serial Shift Clock), and these two clock lines are typically connected to the SCLK pin.

5. A radio frequency transceiver for realizing short-range information transmission according to claim 1, characterized in that: Both data transmission and reception of the microcontroller are buffered by registers; when transmitting information with the TDA5255 RF chip, half-duplex communication is used, and the internal register values ​​of the TDA5255 RF chip are set via the I2C bus protocol.

6. A radio frequency transceiver for realizing short-range information transmission according to claim 1, characterized in that: The microcontroller sets the operating mode of the TDA5255 RF chip, controls the TDA5255 RF chip to send valid information, receives and processes the data received by the TDA5255 RF chip, and connects P1.0 and P1.1 to RXD0 and TXD0 of MAX3232 respectively to complete serial communication with the PC.

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