CN202372203U - Temperature and humidity measuring device based on CAN (Controller Area Network) bus - Google Patents

Abstract

The utility model relates to a temperature and humidity measuring device based on a CAN (Controller Area Network) bus. The temperature and humidity measuring device comprises a data processing and displaying module, and is characterized by being provided with a temperature and humidity information acquiring module and a single CAN bus node module, wherein the temperature and humidity information acquiring module, the single CAN bus node module and the data processing and displaying module are connected. The temperature and humidity measuring device has the beneficial effects that: the instantaneity and accuracy are high; and a CAN bus technology is adopted, so that multi-point measurement of a sensor array is convenient to realize, and the problems of poor accuracy and poor instantaneity of the conventional single-point and separate detection are solved.

Description

A kind of humiture measurement mechanism based on the CAN bus

Affiliated technical field

The utility model relates to the temperature and humidity measurement mechanism, especially relates to a kind of humiture measurement mechanism based on the CAN bus.

Background technology

The temperature and humidity monitoring has very important meaning for aspects such as industry, agricultural and medical and health care system.With the agricultural is example, and humiture not only directly influences growth and development of plant, and agriculture necessity such as agricultural product and agriculture chemical is influenced by ambient temperature and humidity very easily in storage and transportation and situation such as moldy metamorphism occurs; Humiture is also significant to medicine and hygiene fields; Medicine, vaccine and other medical supplies have strict requirement in each links such as production, processing, storage and transportations to ambient temperature and humidity; The bad environment humiture can cause that the inefficacy of medical supplies is rotten, and direct threats is to patient's life security.Ambient temperature and humidity monitoring can be avoided the generation of above-mentioned situation effectively, and reliable foundation is provided for temperature and humidity management.

Existing humiture instrument has mechanical type and digital.Mechanical humiture appearance shows not directly perceived, and the no datat ability to communicate can't be carried out reading of remote monitoring data.The digital Temperature and Humidity appearance can become digital signal with the conversion of signals of humiture, can directly show.General digital Temperature and Humidity appearance is spot measurement, can not measure the humiture of a plurality of measuring points simultaneously.When so common humiture observation system in the market moves; The instability that receives the influence of factors such as transmission range, electromagnetic interference (EMI) easily and become; When especially more or communication distance was far away in measure dot number, it is more serious that the labile factor of system can become.

Continuous development along with automotive electronic technology; The quantity of various electronic control units constantly increases on automobile, the engineering machinery, and volume of transmitted data increases rapidly, and the connection lead between each electronic control unit is also more and more; Therefore; Ask the communication reliability and reduce lead cost and wiring difficulty that for improving electronic control unit German BOSCH has developed the CAN bus protocol, and has developed into international standard.

The CAN bus is the serial communication network of distributed control of a kind of effective support or real-time control.Can be divided into many master-slave modes; Arbitrary node all can initiatively send information to other node on the network; And be regardless of master and slavely, and thereby communication mode is flexible, the last node of CAN is counted reality can reach 110; Communication media can adopt twisted-pair feeder, concentric cable or optical fiber, and highest communication speed can reach 1Mbps (transmission range 40m).The CAN bus structure are simple, and the non-destructive arbitration technique has effectively been avoided bus collision; Reliable fault processing and error-detection mechanism, antijamming capability is strong, can in high-noise environment, work, so the humiture measurement mechanism that designs based on the CAN bus has fine practicality and application prospect.

Summary of the invention

The purpose of the utility model is to overcome the deficiency of existing humiture instrument, and a kind of humiture measurement mechanism based on the CAN bus is provided, and this device interface is simple, is easy to multiple spot array temperature and humidity measurement, and the communication rate high reliability is high, and communication distance is far away.

In order to solve the problems of the technologies described above, the utility model is realized through following technical scheme:

A kind of humiture measurement mechanism based on the CAN bus; Comprise the data processing display module; It is characterized in that: be provided with humiture information acquisition module and single-CAN bus node module, described humiture information acquisition module, single-CAN bus node module and data processing display module are connected;

The integrated Temperature Humidity Sensor of described humiture information acquisition module;

Described single-CAN bus node module comprises single-chip microcomputer, CAN controller and EBI chip for driving, and described single-chip microcomputer, CAN controller and EBI chip for driving are connected.

The humiture information acquisition module collects temperature, humidity information in the single-chip microcomputer, passing through the CAN controller according to certain agreement and error-detection mechanism configuration frame, sends through bus then.The receiving node of system is through interrupting receiving data.Extract data bit through single-chip microcomputer, calculate temperature, humidity value, and be presented on the data processing display module.

The beneficial effect of the utility model is:

Real-time and accuracy are high: adopted the CAN bussing technique; Make things convenient for sensor array to realize multimetering; Adopted intelligent method to different check points with data message merge, changed that traditional single-point and timesharing detection accuracy are poor, the problem of real-time difference; The reliability, accuracy and the real-time that detect have been improved, for warm and humid control system operation provides tactful foundation; Connect a plurality of detecting units through the CAN bussing technique, realized the information sharing of different check point data, shared inspection center's computing machine and database have changed the expensive situation that a traditional detecting unit needs a computing machine.

Description of drawings

Fig. 1 is the logic diagram of circuit of the utility model.

Fig. 2 is the main program flow synoptic diagram of the utility model.

Embodiment

Below in conjunction with accompanying drawing and embodiment the utility model is further specified.

Consult Fig. 1, the embodiment of the utility model provides a kind of humiture measurement mechanism based on the CAN bus,

Be provided with the humiture information acquisition module; The integrated Temperature Humidity Sensor of described humiture information acquisition module; Present embodiment is to adopt inner humiture one body sensor SHT11, and this sensor is accurate digital relative humidity of the monolithic whole school with two-wire serial bus interface and the temperature sensor that Switzerland Sensirion company produces.

Be provided with single-CAN bus node module, the single-CAN bus node module of present embodiment comprises single-chip microcomputer, CAN controller and EBI chip for driving, and described single-chip microcomputer, CAN controller are formed and be connected with the EBI chip for driving.Present embodiment is the AT89S52 single-chip microcomputer that adopts American ATMEL commonly used to produce, and constitutes the single-CAN node by SJA1000CAN controller and P82C250CAN EBI chip for driving.SJA1000 is a kind of independent CAN controller, is the substitute of the PCA82C200 of Philips semiconductor company controller (BasicCAN).It has increased a kind of new mode of operation (PeliCAN), the CAN 2.0B agreement of a lot of new features of this pattern support.Its inside solidification has the CANBUS agreement, can independently carry out the CAN bus protocol by structure.P82C250 is the interface between CAN controller and the physical medium, can drive the node of 110 same P82C250 of employing as EBI.This scheme cost is low, satisfies the design's requirement fully.

Be provided with the data processing display module, present embodiment be LCD (Liquid Crystal Display, LCD), LCM-1602 character mode lcd module, it is one of the most widely used liquid crystal display in the present instrument and meter.

Described humiture information acquisition module, single-CAN bus node module and data processing display module are connected;

The humiture information acquisition module collects temperature, humidity information in the single-chip microcomputer, passing through CAN controller SJA1000 according to certain agreement and error-detection mechanism configuration frame, sends through bus then.The master routine of system is as shown in Figure 2, adopts Basic CAN pattern, and each CAN node regularly 1S sends the humiture data of gathering, and the take over party arbitrates according to the ID difference of message on the bus, and the message that satisfies condition receives in the buffer zone of having opened up.Realize then showing.Master routine is the interruption initialization to using at first, then to the initialization of CAN bus initialization and SHT11 Temperature Humidity Sensor, then circle collection humiture data, send and accept message.Because the collection of humiture needs certain hour, so we adopt timer interrupt timing 1S, 1S has arrived the transmission data.The receiving node of system is through interrupting receiving data.When having data to accept, CAN controller SJA1000 hardware produces and interrupts, and the CAN controller can carry out error-detecting to the frame information that receives simultaneously, has judged whether error code information.If having, the data that receive overflow or mistake, the corresponding positions of the status register of CAN controller meeting set CAN bus controller, and single-chip microcomputer can be to this CAN node warm reset.If the data that receive do not have mistake, extract data bit through single-chip microcomputer, calculate temperature, humidity value, and be presented on the LCDs.Because node is regardless of the principal and subordinate on the CAN bus network, so all nodes of system can be as sending node or receiving node.

Above-described embodiment, related data and computing method are only as schematic illustration, the equivalent arrangements of being done according to the utility model claim such as, the technology that all should be the utility model contains.

Claims (3)

1. humiture measurement mechanism based on the CAN bus; Comprise the data processing display module; It is characterized in that: be provided with humiture information acquisition module and single-CAN bus node module, described humiture information acquisition module, single-CAN bus node module and data processing display module are connected.

2. a kind of humiture measurement mechanism based on the CAN bus according to claim 1 is characterized in that: the integrated Temperature Humidity Sensor of described humiture information acquisition module.

3. a kind of humiture measurement mechanism based on the CAN bus according to claim 1 is characterized in that:

Described single-CAN bus node module comprises single-chip microcomputer, CAN controller and EBI chip for driving, and described single-chip microcomputer, CAN controller and EBI chip for driving are connected.

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