CN109286923B

CN109286923B - Communication method based on Bluetooth

Info

Publication number: CN109286923B
Application number: CN201811184457.7A
Authority: CN
Inventors: 欧阳海军
Original assignee: Guangzhou Guoou Electronic Technology Co ltd
Current assignee: Guangzhou Guoou Electronic Technology Co ltd
Priority date: 2018-10-11
Filing date: 2018-10-11
Publication date: 2021-09-07
Anticipated expiration: 2038-10-11
Also published as: CN109286923A

Abstract

The invention discloses a communication method based on Bluetooth.A host and a slave receive and send data mutually and follow a data frame structure, the data frame is divided into a frame header and a text, the frame header and the text are changed according to different functions, and the size range of the text is 0-516 bytes; when the length of the data frame exceeds 20 bytes, 100 ms delay is inserted every 20 bytes sent; after a sending party sends a data frame, the sending party waits for 500 milliseconds to send the next data frame again, and under the condition that the receiving party detects that no new data is received within 300 milliseconds, the receiving party judges that the data frame is ended or the connection is interrupted. Actively uploading all data in the measurement process in real time, and enabling an upper computer to synchronously acquire all latest data; the real-time uploaded data has fields such as data numbers and the like, and can be used for judging whether data are lost; the upper computer can acquire all data, settings and the like of the thickness gauge under the condition of data loss caused by unstable connection and the like; in case of unstable connection, it can be determined that the data is in error and retransmitted.

Description

Communication method based on Bluetooth

Technical Field

The invention relates to the technical field of communication, in particular to a communication method based on Bluetooth.

Background

In the existing measuring method of the coating thickness gauge, generally, an operator uses the coating thickness gauge to obtain paint film thickness data, the paint film thickness data is recorded on a notebook, and whether the paint film is normal or not is judged by observing the measured thickness data. The measuring method is troublesome, errors are easy to occur in manual recording, and certain experience is still needed for data observation.

Instead of manual recording, a method of general recording may be adopted, which can avoid errors caused by manual data recording and misjudgment caused by insufficient human experience, but may cause data loss due to unstable connection.

Disclosure of Invention

The invention aims to provide a communication method based on Bluetooth, which is stable in communication connection, can judge data transmission errors and retransmits the data.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a communication method based on Bluetooth, both communication parties are a slave computer and an upper computer, and the communication between the upper computer and the slave computer comprises the following steps:

s1, the upper computer searches the slave computers through Bluetooth and matches and connects the slave computers;

s2, the upper computer sends an instruction to request slave computer identity recognition;

s3, the slave responds to the identity request command and sends back the model, serial number, software and hardware version and version information of the communication protocol supported by the slave to the upper computer;

s4, the upper computer sends a synchronization setting instruction;

s5, the slave replies the setting information of the slave;

s6, the upper computer judges the working mode of the slave computer according to the setting information replied by the slave computer;

s7, the upper computer sends a synchronization instruction according to the working mode of the slave computer, and the data synchronization of the upper computer and the slave computer is completed;

the data receiving and sending of the host and the slave follow the structure of a data frame, the data frame is divided into a frame head and a text, the frame head is 8 bytes, the length of the text is not fixed, the text is changed according to different functions, and the size range of the text is 0-516 bytes;

when the length of the data frame exceeds 20 bytes, 100 ms delay is inserted every 20 bytes sent;

after a sending party sends a data frame, the sending party waits for 500 milliseconds to send the next data frame again, and under the condition that the receiving party detects that no new data is received within 300 milliseconds, the receiving party judges that the data frame is ended or the connection is interrupted.

Preferably, the method further includes step S8, when the slave has new measurement data or the slave is changed in setting, the slave will actively report to the upper computer, and the upper computer performs corresponding processing.

Preferably, the encoding of the body part is an ASCII code encoded character string.

Preferably, all the checks between the slave computer and the upper computer adopt CRC16 check, and if the content to be checked does not contain the check code, the calculation is directly carried out; if the content to be checked contains the check code, the check code field is cleared, then the CRC16 check code is calculated for all the content to be checked, and then the calculated value is filled into the check code field.

Preferably, the upper computer is an Android, IOS or Windows device with a Bluetooth function.

Preferably, the slave machine is a Bluetooth coating thickness gauge with a Bluetooth function.

The invention has the beneficial effects that:

1. by adopting Bluetooth wireless communication, the coating thickness gauge can be communicated with a mobile phone, a tablet personal computer or a PC personal computer;

2. the special instruction is used for inquiring information such as the model, the serial number, the supported protocol version and the like of the thickness gauge, so that the condition of the thickness gauge is conveniently judged and authenticated, and the subsequent communication protocol is conveniently upgraded;

3. the thickness gauge can actively upload all data in the measuring process in real time, and the upper computer can synchronously acquire all latest data;

4. the real-time uploaded data has fields such as data numbers and the like, and can be used for judging whether data are lost;

5. the upper computer can acquire all data, settings and the like of the thickness gauge through synchronous instructions when the upper computer is connected for the first time or the upper computer is connected unstably and the like to cause data loss;

6. all data has CRC16 check, and in case of unstable connection, the data can be judged to be in error and retransmitted.

Drawings

The invention is further illustrated with reference to the following figures and examples.

Fig. 1 is a schematic diagram of a bluetooth-based communication method according to an embodiment of the present invention.

Detailed Description

The present invention is further described with reference to the following drawings and specific examples so that those skilled in the art can better understand the present invention and can practice the present invention, but the examples are not intended to limit the present invention.

Fig. 1 is a communication method based on bluetooth according to one embodiment, in which two communication parties are a slave and an upper computer, and the communication between the upper computer and the slave includes the following steps:

s4, the upper computer sends a synchronization setting instruction;

s5, the slave replies the setting information of the slave;

1. Data frame format:

the master and the slave transmit and receive data to and from each other following a data frame structure. The data frame is divided into a frame header and a text, and the frame header is 8 bytes. The text length is not fixed and is changed according to different functions, and the text size range is 0-516 bytes. As shown in the following table:

all data transmission adopts a small-end mode, namely low byte is transmitted first. For example, assuming the source port is 0x0001, the lower byte 0x01 is sent first, and then the upper byte 0x00 is sent.

Source port: indicating the source of the data frame.

Destination port: indicating the removal of the data frame.

The two fields, source and destination, together determine the class of data frame. The upper computer and the slave support different source and destination ports, respectively, as will be described in detail below.

Frame length: the byte number of the whole data frame comprises a frame header and a text part. Because the text length is 0-516 bytes, the frame length range is: 8 to 524.

CRC16 check code: the data of the whole data frame is checked, so that a receiver can conveniently judge whether the data is lost or damaged in the transmission process.

The text is as follows: text information to be transmitted for the data frame. There are parts of the data frame that do not require text.

2. Data frame sub-packaging:

in order to ensure stable link layer communication and ensure enough processing time of a master side and a slave side, when the length of a data frame exceeds 20 bytes, 100 millisecond delay is inserted every 20 bytes are sent.

3. Data frame demarcation:

after a sender sends a data frame, the sender should wait 500 milliseconds before sending the next data frame; when the receiving side detects that no new data is received within 300 milliseconds, the receiving side judges that the data frame is ended or the connection is interrupted.

Because each data frame has a frame length field, if no data error or loss occurs in the communication process, the receiving side can directly judge that the data frame is ended, and the receiving side can reply without waiting for 300 milliseconds. The sender does not need to wait 500 ms any more if it has received the receiver's reply.

4. Data frame sent (received) by upper computer

4.1 identification Instructions

After receiving the command, the slave machine replies the identification information. See "5.1 identification information"

4.2 coating measurement mode: data synchronization instruction

After receiving the command, the slave replies the data set and the setting information, see "5.3 coating measurement mode setting information" and "5.4 coating measurement mode: current group data ".

4.3 vehicle paint detection mode: acquiring finished automobile data instruction

After receiving the command, the slave computer replies the data of the whole vehicle, and the method is shown in a 5.6 vehicle paint detection mode: data of the entire vehicle "

4.4 vehicle paint detection mode: remotely switching measurement locations and clearing the location data instructions

The site codes are shown in the following table:

4.5 vehicle paint detection mode: remote clearing data instruction of whole vehicle

4.6 vehicle paint detection mode: remote acquisition of measurement sequence instructions

After receiving the command, the slave machine will revert to the current measurement sequence setting, see "5.7 car paint detection mode: measurement order data "

4.7 vehicle paint detection mode: remotely specifying measurement order instructions

The upper computer can specify the positions and the sequence of the slave computers needing to be measured, so that some measuring parts are omitted (for example, some vehicle types do not have D columns, and the measuring parts can be omitted), or the measuring sequence is changed.

The measurement order text, 19 bytes, specifies the measurement order of each point, uses one measurement number for each site (as shown in the following table), and if there are less than 19 points to be measured, it is necessary to complement FF (16 m) at the end. For example, without testing the B-pillar, the roof is tested first, and the other sequences are left unchanged: 100001020305060708090A 0B 0D 0E 0F 1112 FF

Measurement site numbering table:

name of location	Position number (hexadecimal)
		Front engine room cover	00
Right front lappet	01
		Right A column	02
Right front door	03
		Right B column	04
Right back door	05
		Right C column	06
Right rear fender	07
		Trunk lid	08
Left rear fender	09
		Left C column	0A
Left back door	0B
		Left B column	0C
Left front door	0D
		Left A column	0E
Left front fender	0F
		Vehicle roof	10
Left D column	11
		Right D column	12

5. Data frame sent from slave (received by upper computer)

5.1 identification information

After the instrument receives the '4.1 identification instruction' sent by the upper computer, the following identification information can be replied

The text part is a character string coded by ASCII code: each row starts with two capital letters and an equal sign; ending with the line break '\ n', i.e., ASCII code 0x0A, an example is as follows:

MD＝Guoou-T2M

SN＝1234567

HV＝1.00u

SV＝1.01a

CP＝1.0

CS＝Hi

field(s)	Content providing method and apparatus
		MD	Instrument type
SN	Instrument serial number
		HV	Hardware version number
SV	Software version number
		CP	Communication protocol version, currently 1.0
CS	Communication speed, Lo for low-speed communication and Hi for high-speed communication

5.2 coating measurement mode: real-time data

In the coating measuring mode, the instrument uploads the following data frame each time new data is measured

The text real-time data structure is as follows:

group creation time	Data start address	Number of data	Current value	Type of base
					4 bytes	1 byte	1 byte	4 bytes	1 byte

Group creation time: the 32-bit (4-byte) unsigned integer number representing the creation time of the current data group can judge whether to switch to a different data group according to the field, and if the data group is switched, data synchronization needs to be carried out once.

Data start address: the data is covered in a circular loop in the data group, the upper limit of the group capacity is 60, and the 61 st digit of the measurement is stored in the position of the 1 st digit stored firstly. This field indicates the location of the current data store.

The number of data is as follows: the number of data existing in the group is 60 at most.

By connecting the 2 fields, whether the real-time data is lost or not can be judged: if the data group is not full, the value of the field of the number of data should be increased by 1 each time, and if the value is increased by more than 1, data loss is indicated; if the data group is full, the "number of data" field should remain unchanged, the "start address of data" field should be incremented by 1 each time, and if the incremented number exceeds 1, then data loss will occur. If a loss occurs, one data synchronization is required.

Current value: 4 bytes single precision floating point type (IEEE754 single precision floating point type standard), unit micrometer (μm).

Type of matrix: 'F' denotes a magnetic matrix and 'N' denotes a non-magnetic matrix.

5.3 coating measurement mode: setting information

The instrument was operated in the "4.2 coating measurement mode: after the data synchronization command, two data frames are recovered. One of the data frames representing the current setting of the instrument is

The text of the setup message is shown in the following table:

where "start position" indicates the offset of the field in the frame body.

5.4 coating measurement mode: current group data

The instrument was operated in the "4.2 coating measurement mode: after the data synchronization command, two data frames are recovered. Two of the following data frames represent information and all data of the current data set

The text of the current group of data is shown in the following table:

5.5 vehicle paint detection mode: real-time data

When the instrument is in the vehicle paint detection mode, the following data frames are uploaded every time new data are measured

The text real-time data structure is as follows:

vehicle number	Detection site	Total number of parts	Current serial number of part	Data of
					2 bytes	3 bytes	1 byte	1 byte	4 bytes

Vehicle number: 0x 0001-0 xFFFF

Detection of the site: the position number of 3 bytes ASCII code is detailed in a 4.4 vehicle paint detection mode: remotely switching the measurement position and clearing the byte value of the ASCII code in the position data command

Total number of sites: the number of times a certain vehicle part (e.g. hood) needs to be measured is 6 or 9

Current sequence number of the part: the currently measured value is the number of values of the current position and ranges from 0x01 to 0x09

Data: single precision floating point type float data, 4 bytes, little-end mode (i.e. low byte first transfer). For example, a floating point type of 82.5 is represented as 0x42a50000, and the data portion is 0x00,0x00,0xa5,0x42.

5.6 vehicle paint detection mode: vehicle data

The instrument was in "4.3 car paint detection mode: after acquiring the data instruction of the whole vehicle, the measurement data of the whole vehicle can be replied

1) Data segment

The whole vehicle data is divided into a plurality of data segments, and each data segment represents a measuring position. The data segment structure is as follows:

measurement site

Total number of points of the part

Data 1

Data 2

Data 3

Data 4

Data 5

Data 6

Measurement site: 3 bytes, and "5.5 car paint detection mode: the "detection sites" in the "real-time data" are the same.

Total number of sites: 1 byte, 0x6 or 0x9

Data x: single precision floating point type float data, 4 bytes, little-end mode (i.e. low byte first transfer).

For example, a floating point type of 82.5 is represented as 0x42a50000, and the data portions are 0x00,0x00,0xa5,0x42.

The unmeasured data is represented by NAN, i.e. 0x7fc00000, as: 0x00,0x00,0xc0,0x7f.

2) Vehicle data

The whole vehicle data has 1024 bytes, and is formed by sequentially connecting data segments of all parts, and the part with less than 1024 bytes is filled with useless data.

3) Whole vehicle data frame format

Because the total vehicle data is 1024 bytes, which exceeds the maximum size 516 of the text of a single data frame, the total vehicle data is sent by using 2 continuous data frames, and the two data frames are respectively as follows:

5.7 vehicle paint detection mode: measuring sequential data

The instrument received "4.6 car paint detection mode: after the measurement sequence command is remotely acquired, the current measurement sequence setting can be replied

Text format references "4.7 vehicle paint detection mode: text description of remote specified measurement order instruction ".

6, a verification algorithm:

all checks of the protocol use CRC16 checks. If the content to be verified does not contain the verification code, directly calculating; if the content to be checked contains the check code itself (for example, the check code exists in the middle of the content to be checked), the check code field is cleared first, then the CRC16 check code is calculated for all the content to be checked, and then the calculated value is filled into the check code field.

The following is one of the more convenient measurement techniques of operating personnel, detect each part of automobile body in proper order: the device comprises a front engine room cover, a right front fender, a right A pillar, a right front door, a right B pillar, a right rear door, a right C pillar, a right rear fender, a right D pillar, a trunk cover, a left D pillar, a left rear fender, a left C pillar, a left rear door, a left B pillar, a left front door, a left A pillar, a left front fender and a roof, wherein each part is measured for 6-9 times. After measuring a part, can press down the measurement that key got into next part, also can be through clicking corresponding part name and image in the APP, send the bluetooth instruction to the calibrator through the APP, appoint the part that next step needs to be measured. In the case where there is no corresponding part in the vehicle body (e.g., D-pillar), the down button is pressed to skip the part and continue the measurement of the next part.

The data communication between the coating thickness gauge and the mobile phone adopts an autonomous communication protocol, and the correctness and the validity of transmitted data are verified; the data may be automatically retransmitted by the protocol in case of connection instability. Besides receiving and processing data, the mobile phone can also be used as a remote controller to control the coating thickness gauge. Through the real-time measurement data of uploading of bluetooth for cell-phone APP, avoid the mistake that the artificial record data leads to.

The mobile phone is connected with the database of the network server through the network, the mobile phone can send data to the network server through the network, and the network server has the functions of data calculation and analysis and can send the analysis result back to the mobile phone through the network again to enable a user to know the analysis result. The APP and the server are communicated to obtain a film condition evaluation result, so that misjudgment caused by insufficient human experience is avoided.

The above-described embodiments of the present invention are not intended to limit the scope of the present invention, and the embodiments of the present invention are not limited thereto, and various other modifications, substitutions and alterations can be made to the above-described structure of the present invention without departing from the basic technical concept of the present invention as described above, according to the common technical knowledge and conventional means in the field of the present invention.

Claims

1. A communication method based on Bluetooth is characterized in that two communication parties are a slave computer and an upper computer, and the communication between the upper computer and the slave computer comprises the following steps:

s4, the upper computer sends a synchronization setting instruction;

s5, the slave replies the setting information of the slave;

s8, when the slave has new measurement data or the slave is changed in setting, the slave will actively report to the upper computer, and the upper computer performs corresponding processing;

2. The bluetooth-based communication method according to claim 1, wherein: the encoding of the body part is a string encoded in ASCII code.

3. The bluetooth-based communication method according to claim 1, wherein: all the checks between the slave computer and the upper computer adopt CRC16 check, if the content to be checked does not contain the check code, the calculation is directly carried out; if the content to be checked contains the check code, the check code field is cleared, then the CRC16 check code is calculated for all the content to be checked, and then the calculated value is filled into the check code field.

4. The bluetooth-based communication method according to claim 1, wherein: the upper computer is Android, IOS or Windows equipment with a Bluetooth function.

5. The bluetooth-based communication method according to claim 1, wherein: the slave machine is a Bluetooth coating thickness gauge with a Bluetooth function.