CN102801818A - Universal sensor interface acquisition system based on ZigBee technology - Google Patents

Abstract

The invention relates to a sensor universal interface acquisition system based on ZigBee technology, which belongs to the field of wireless communication and electronic technology. Including ZigBee module, power supply module, sensor general interface module and digital packaging sensor module; the microcontroller of ZigBee module simulates its I/O port as a serial transmission bus clock line and data line, and connects with the sensor general interface module; power supply module Provide power to the ZigBee module through the power line and ground line; the sensor general interface module includes clock line, power line, ground line and data line; the digital package sensor module and the sensor general interface module through the clock line, power line, ground line and data line connect. The invention realizes the plug-and-play of specific packaged sensors through the common interface of the sensor, avoids the circuit change of different types of data acquisition, improves the compatibility and effectiveness of the system, and reduces the cost.

Description

Sensor general interface acquisition system based on ZigBee technology

technical field

The invention relates to an acquisition system based on ZigBee technology, in particular to a sensor general interface, which belongs to the field of wireless communication and electronic technology.

Background technique

The development of microelectronics technology, computing technology and wireless communication technology has promoted the development of low-power multifunctional sensors, which can integrate multiple functions such as information collection, data processing and wireless communication in a small volume. The wireless sensor network is to integrate the logical information world and the objective physical world to realize the collection, transmission and processing of information in the objective physical world. The data acquisition unit sensor node of the wireless sensor network is mainly composed of four parts: sensor module, processor module, wireless communication module and energy supply module. ZigBee technology is a two-way wireless communication technology or wireless network technology with short distance, low complexity, low power consumption, low data rate and low cost. and communication technology in terms of application software. However, the current data acquisition system based on wireless sensor networks in my country still has the following problems:

1. The sensor node structure is complex. In a wireless sensor network, a sensor node is generally composed of four modules: sensor module, processor module, wireless communication module and energy supply module. Pin connections and peripheral circuits, resulting in complex circuits and many connections, once connected, it is not easy to change.

2. There are many types of sensors, and each sensor requires a connection circuit. According to the different types of measured physical quantities, different working principles, and different types of output signals, various sensors can be divided. Each sensor has its own pin structure, working sequence, and connection method with the processor. When the data acquisition system needs to collect a variety of data, it is necessary to design different connection circuits for different sensors.

3. The sensor design is not uniform and lacks versatility. Even the same type of sensor has different pin designs and output signal types, some have three pins, some have four pins, some have digital output, and some have analog output, resulting in the need to collect a variety of physical data. The connection method lacks versatility.

4. The plug and play of the sensor cannot be realized. Once the circuit welding of the sensor node is completed, the circuit cannot be changed unless the circuit is re-soldered. In general, the sensor node needs to collect different physical data by replacing the sensor, so it needs to be constantly changed and welded. The lack of a sensor plug-in Ready-to-use interface.

5. Poor compatibility and high cost. A data acquisition system based on a wireless sensor network needs to collect various types of data. Different data acquisition corresponds to different sensors, different connection circuits, constant changes, and welding circuits. The system compatibility is poor, and unnecessary resources are wasted.

Contents of the invention

Aiming at the defects existing in the prior art, the present invention provides a sensor universal interface acquisition system based on ZigBee technology. The system structure is simple and there are few connecting lines, no need to change the circuit. A variety of data, low cost, high efficiency, good compatibility.

Technical scheme of the present invention is:

The invention provides a sensor general interface acquisition system based on ZigBee technology, the system is composed of four parts: ZigBee module 1, power supply module 2, sensor general interface module 3 and digital packaging sensor module 4.

ZigBee module 1 is responsible for controlling the operation of the entire sensor node, including transmitting control commands, storing and processing the data collected by itself; responsible for wireless communication with other sensor nodes, exchanging control information and sending and receiving collected data. ZigBee module 1 refers to the power supply pin, ground pin and two I/O pins of the ZigBee chip, as the power line, ground line, clock line and data line, and through the clock line, power line, ground line and data line and The sensor common interface module 3 is connected. Wherein the power supply line and the connection line provide the operating voltage for the sensor general interface module 3; the ZigBee module 1 simulates the two I/O pins of the port 1 as a serial transmission bus through a microcontroller, which are clock lines and data lines respectively. It is used to transmit control commands and collect monitoring data.

The power supply module 2 is composed of two AA batteries, and the positive and negative poles of the batteries lead out a power line and a grounding line respectively. The power supply module 2 is connected with the ZigBee module 1 through a power line and a ground line, and provides the ZigBee module 1 with a working voltage of 3V.

The sensor general interface module 3 includes a clock line, a power line, a connection line and a data line, and the shape adopts a PIN jack. The sensor general interface module 3 is connected with the digital packaging sensor module 4 through clock lines, power lines, ground lines and data lines. Among them, the PIN jack adopts a single-row four-hole jack form, the No. 1 jack is the clock line, the No. 2 jack is the power line, the No. 3 jack is the grounding line, and the No. 4 jack is the data line. The jack spacing is 2.54 mm. The sensor universal interface module 3 provides a plug-and-play jack for the multifunctional unified digital package sensor, which is convenient, fast and efficient.

The digital packaging sensor module 4 packages the sensor and its peripheral circuits on a PCB board, and leads out four pins which are respectively clock lines, power lines, ground lines and data lines. The sensor is responsible for sensing and collecting monitoring information in the monitoring area, and the peripheral circuit is to ensure the digital output of the digital package sensor module 4 . When the packaged sensor is a digital sensor, it can be directly packaged according to the four-wire output; when the packaged sensor is an analog sensor, it is necessary to connect the sensor to peripheral circuits such as A/D converters and serial interfaces to ensure four-wire output. digital output. The power line and the ground line provide 3V working voltage for the digital packaging sensor module 4 through the sensor general interface module 3; the clock line and the data line cooperate with each other to complete the transmission of the control command and the transmission of the collected monitoring data. The shape of the digital package sensor module 4 uses four-pin single-row PIN pins as pins, pin 1 is the clock line, pin 2 is the power line, pin 3 is the ground wire, and pin 4 is the data line , the pin spacing is 2.54mm, the pin length is 6.35mm, and the pin size is consistent with the PIN jack of the sensor universal interface module 3, realizing plug-and-play seamless connection.

The beneficial effects of the present invention are:

1. The node circuit of the present invention replaces two modules of the processor module and the wireless communication module with a ZigBee module, and the whole circuit only has four connecting wires of the clock line, the power supply line, the ground wire and the data line, and the structure is simple and clear, which reduces the production cost , and complete the most needed functions with the least modules and connecting lines.

2. The sensor universal interface of the present invention provides a socket for connecting various sensors to the circuit, and selects different sensors to insert into the socket according to different types of measurement data, without changing the circuit, which is convenient and quick.

3. In order to realize the plug-and-play function of the universal interface, the digital packaging sensor of the present invention is uniformly packaged according to the hardware specification and timing specification required by the invention before leaving the factory, so as to realize the unified packaging of the sensor, which is easy to install and improves the utilization rate.

4. The present invention is applicable to a collection system that collects multiple types of data at the same time. For different collection tasks, it only needs to replace specific packaged sensors without other operations, which is efficient, fast, and resource-saving.

Description of drawings

Fig. 1 is the structural representation of the sensor general interface acquisition system based on ZigBee technology that the present invention provides;

Fig. 2 is a schematic diagram of the general interface of the sensor provided by the present invention and the external dimensions of the digital package sensor;

Among them: Figure 2(a) is a schematic diagram of the external dimensions of the sensor's general interface; Figure 2(b) is a schematic diagram of the external dimensions of the digital package sensor;

Fig. 3 is the structural representation of a kind of sensor universal interface acquisition system based on ZigBee technology that the embodiment of the present invention provides;

Fig. 4 is a flow chart of the data acquisition program of the digital temperature and humidity sensor DHT90 provided by the embodiment of the present invention.

Detailed ways

A specific embodiment of the present invention will be described below in conjunction with the accompanying drawings.

The structural diagram of the general interface acquisition system for sensors based on ZigBee technology in the present invention is shown in FIG. 1 . Including ZigBee module 1, power supply module 2, sensor general interface module 3 and digital packaging sensor module 4; ZigBee module 1 is connected with sensor general interface module 3 through clock line, power line, ground line and data line; power supply module 2 is through power line and the ground wire are connected to the ZigBee module 1; the sensor general interface module 3 is connected to the digital package sensor module 4 through the clock wire, the power wire, the ground wire and the data wire.

Accompanying drawing 3 is an embodiment of the sensor general interface acquisition system based on ZigBee technology:

The HFZ-CC2430EM-22 module is selected as ZigBee module 1, which is responsible for controlling the operation of the entire node, sending control commands, processing and sending collected data, and wirelessly communicating with other nodes to form a multi-hop self-organizing network system. This module adopts the ZigBee radio frequency chip CC2430 of Texas Instruments (TI), integrates high-performance 8051 core, ADC, USART, etc. on the chip, and supports the ZigBee protocol stack. The module has a total of 24 pins that are 19 I/O ports, including all P1 ports, P0 ports and P2_0, P2_1, P2_2 ports, 2 power pins, 2 ground pins, and a reset pin , The pin pitch is 2.54mm. Among them, the 8051 microcontroller integrated on the CC2430 chip simulates the P1_1 and P1_3 ports as a serial transmission bus as a clock line and a data line, which are respectively connected to the No. 1 jack and No. 4 jack of the sensor general interface module 3; The pin and the ground pin are respectively connected to the No. 2 jack and the No. 3 jack of the sensor general interface module 3 .

Two AA batteries are selected as the power module 2, which is responsible for providing 3V working voltage for the ZigBee module 1, sensor general interface module 3 and digital package sensor module 4. Two AAA batteries are connected in series, the positive pole is connected to the power pin of the HFZ-CC2430EM-22 module, and the negative pole is connected to the ground pin of the HFZ-CC2430EM-22 module.

A single-row four-hole PIN jack is selected as the sensor general interface module 3, which is responsible for providing a plug-and-play socket for digitally packaged sensors. The No.1 jack is the clock line, the No.2 jack is the power cord, the No.3 jack is the ground wire, and the No.4 jack is the data line. Show. The No. 1 jack, the No. 2 jack, the No. 3 jack, and the No. 4 jack are respectively connected to the No. 1 pin, the No. 2 pin, the No. 3 pin, and the No. 4 pin of the digital packaging sensor module 4 .

The digital temperature and humidity sensor DHT90 in the pin type package is selected as the digital package sensor module 4, which is responsible for the perception, collection and conversion of the collected data. DHT90 includes a capacitive polymer humidity sensor, a temperature sensor made of energy gap material, and seamless connection with 14-bit A/D converter and serial interface circuit on the same chip; four pins Single-row pin package, from top to bottom are pins 1 to 4, of which pin 1 is the clock line SCK, pin 2 is the power line VDD, pin 3 is the wire GND, The No. 4 pin is the data line DATA, the pin pitch is 2.54mm, and the pin length is 6.35mm. The sensor is packaged on the PCB. The schematic diagram of the external dimensions is shown in Figure 2(b). The operating voltage range of DHT90 is 2.4-5.5V, and the working voltage of 3V is selected in this embodiment, so the No. 2 pin and No. 3 pin are connected to the No. 2 jack and No. The power pin and ground pin of the module are connected; pin 1 and pin 4 of the DHT90 are connected to P1_0 and P1_3 of the HFZ-CC2430EM-22 module through the pin 1 and pin 4 of the PIN jack, and the DHT90 Pins 1 to 4 of the corresponding to jacks 1 to 4 inserted into the PIN jack.

After the hardware connection of the embodiment is completed according to the above method, the software design of the whole system is started. IARE Embedded Workbench (IAR Embedded Workbench) is used as the software development platform. It is widely used because of its powerful debugging function and friendly interface. It is suitable for developing embedded operating systems based on 32/16/8-bit microprocessors. IAR integrates C-SPY debugger, project manager, file editor, library manager, linker, assembly tool and C/C++ editor in one. There is also a code optimizer in the IAR software, which enables the IAR embedded workbench to generate reliable and efficient FLASH codes for 8051 series chips. The compiler of IAR Embedded Workbench has the following features: memory mode selection, high-efficiency floating-point support, bottleneck performance analysis, convenient interrupt simulation and processing, good support for extended tools and version control, extended target features, and is fully compatible with standard C.

The steps for developing the embodiment system using IAR EW are as follows:

(1) Set project options.

(2) Edit and compile source files to generate application program files.

(3) Connect the target module, including debugging options.

(4) Debug the program, if there is an error, return to the second step to modify the file and then re-debug.

(5) After the debugging is successful, exit the debugging option and complete the program download of the SoC.

The program design of the sensor nodes in the system of the embodiment mainly consists of two parts, one part is responsible for realizing networking and data transmission between nodes, and the other part is responsible for realizing the collection and reading of sensor monitoring data.

The working process of networking and data transmission between nodes is to initialize the sensor nodes first. After the initialization is completed, the nodes send a signal to request to join the network, which can be realized by directly joining the network with the parent node. If the sensor node is successfully connected to the network, the sensor node Start to collect data on the objects in the monitoring area. After the data collection is completed, send the collected data to the sink node, that is, the coordinator. After the sending is successful, return to the information collection stage, continue to collect data, and collect data and send data repeatedly.

The integrated 8051 microcontroller on DHT90 and CC2430 completes the sending of control commands and the transmission of collected data through the mutual cooperation of clock lines and data lines. Refer to Figure 4 for the data acquisition program flow of the temperature and humidity sensor DHT90. The specific process is: first power on the sensor to make the sensor enter a dormant state; after the sensor is started, the microcontroller sends a start transmission sequence to the sensor to complete the initialization work ;After the initialization sequence is sent, the microcontroller sends a measurement command to the sensor, and the sensor determines whether to accept the command; after confirming that the command is received, wait for the measurement data until the sensor indicates that the data measurement is completed; restart the clock after the data measurement is completed, and the microcontroller reads the measurement Data, the communication ends after the data is read.

Claims (9)

1. a sensor general interface acquisition system based on ZigBee technology, is characterized in that, described system is made up of ZigBee module (1), power supply module (2), sensor general interface module (3) and digital encapsulation sensor module (4) ; Described ZigBee module (1) is connected with sensor universal interface module (3) by clock line, power line, ground wire and data line; Described power supply module (2) is connected with ZigBee module (1) by power line and ground wire ; The sensor general interface module (3) is connected to the digital packaging sensor module (4) through a clock line, a power line, a ground line and a data line. 2. according to the sensor universal interface collection system based on ZigBee technology according to claim 1, it is characterized in that, described ZigBee module (1) is simulated as serial transmission by two I/O pins of port 1 by microcontroller Bus, which are clock lines and data lines, are used to transmit control commands and collect data; the ZigBee module (1) only uses power pins, ground pins and the above two I/O pins as power lines, ground lines, clock and data lines. 3. according to the sensor universal interface collection system based on ZigBee technology according to claim 1, it is characterized in that, described power supply module (2) adopts two joints No. 5 batteries to provide 3V for ZigBee module (1) by power line and ground wire working voltage. 4. according to the sensor universal interface collection system based on ZigBee technology according to claim 1, it is characterized in that, described sensor universal interface module (3) comprises clock line, power supply line, connecting wire and data line, and profile adopts PIN jack . 5. according to the sensor universal interface module (3) described in claim 4, it is characterized in that, described PIN jack adopts single-row four-hole jack form, and No. 1 jack is clock line, and No. 2 jack is power cord , The No. 3 jack is the ground wire, the No. 4 jack is the data line, and the distance between the jacks is 2.54mm. 6. according to the sensor general interface acquisition system based on ZigBee technology according to claim 1, it is characterized in that, described digital encapsulation sensor module (4) is that sensor and peripheral circuit thereof are packaged on a PCB board, and draw four The pins are clock line, power line, ground line and data line respectively; the digital package sensor module (4) is connected with the sensor general interface module (3) through the clock line, power line, connection line and data line; the shape adopts four-pin single Pin row package; the output acquisition data is digital output. 7. according to the sensor universal interface collection system based on ZigBee technology according to claim 1, it is characterized in that, described power line and ground wire provide the work of 3V for digital encapsulation sensor module (4) by sensor universal interface module (3) voltage; the clock line and the data line cooperate with each other to complete the sending of control commands and the transmission of collected data. 8. according to the sensor universal interface acquisition system based on ZigBee technology according to claim 6, it is characterized in that, described four pin single-row pin package adopts PIN pin as pin, No. 1 pin is clock line, No. 2 The pin is the power line, the 3rd pin is the grounding line, and the 4th pin is the data line, the pin spacing is 2.54mm, and the pin length is 6.35mm. 9. according to the sensor universal interface acquisition system based on ZigBee technology according to claim 6, it is characterized in that, when packaged sensor is digital sensor, can output according to four wires and directly package; When the sensor of package is analog sensor, The sensor needs to be connected to the serial interface through the A/D converter to ensure the four-wire digital output.

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