KR20010094576A - Weight measuring apparatus using personal computer - Google Patents

Abstract

PURPOSE: A weighting machine using a PC is provided for a user to show the own weight and health condition any time and manage the record by simply connecting the weighting machine to the PC. CONSTITUTION: A load cell(12), which is mounted on the lower side of the weighting board, is electrically connected with an amplifier(13), a low path filter(14), and an A(Analog)/D(Digital) converter(15). A micom(16) controls the amplifier, low path filter, and A/D converter through a controller logic(17). A memory(18) performs backup of the auto-zero adjust function and span adjust calibration data, and remembers the needed data in power-off. A communication port(19) is connected with a body of the PC(20) through an RS232C line(30). The PC includes a monitor(22) which displays the result of a software, a keyboard(23) which inputs every instruction, and a speaker(24) which generates various multimedia. The mechanical power pressed on the weighting board is converted into an electronic weighting signal through a sensor of the load cell. The electronic weighting signal is converted into a digital signal through the amplifier, low path filter, and A/D converter, and transferred to the PC in the RS232C type through the micom. The PC receives the weighting data, displays the weight value on the monitor by driving a specific software program, and executes the memory, recording, and processing.

Description

Weighing apparatus using personal computer {Weight measuring apparatus using personal computer}

The present invention relates to a relay device using a personal computer, and more particularly, a personal computer that can display and monitor the weight and related health conditions from time to time by simply connecting to a personal computer widely used in a home or office, and storing and managing records. It relates to the used repeater.

A general electronic relay device uses a load sensor such as a load cell to convert a physical quantity into an electrical signal, amplifies and converts it into an A / D, inputs it into a microprocessor, and processes the microprocessor to display it on a digital display. Leave.

However, the conventional weighing apparatus is a unitary type, in which a weighing table, an electronic circuit, a display printer, and the like are integrated, and are sold for a professional business for the purpose of precise weighing.

In order to connect such relay device with PC, it is necessary to use a dedicated communication line or attach a special device, and send only simple data information to the PC, and the PC aggregates it and uses it as data for transmission only.

Therefore, an object of the present invention is to solve the above-mentioned shortcomings, using a personal computer that can be easily connected to a personal computer or office and widely connected to the home and office to observe the weight and health conditions associated with it at any time and store and manage records. Provide a repeater.

1 is an exemplary view showing a schematic configuration of a device according to the present invention;

2 is a block diagram showing the circuit configuration of the main functional units of the apparatus according to the present invention;

3 is a flowchart showing the operation of the repeater in the apparatus according to the present invention,

4 is a flowchart showing the operation of the personal computer in the apparatus according to the present invention;

5 is a screen state diagram showing a pop-up menu in the normal mode according to the present invention;

6 is a screen state diagram showing a pop-up menu in the setting mode according to the present invention.

Explanation of symbols on the main parts of the drawings

10: repeater 12: load cell

13 amplifier 14 low pass filter

15: A / D Converter 16: Micom

17: control logic 18: memory

19: communication port 20: personal computer (PC)

21: body 22: monitor

23: keyboard 30: communication line

In order to achieve the above object, the present invention provides a relay apparatus for digitally processing an analog signal generated by the load cell 12 by an amplifier 13, a low pass filter 14, and an A / D converter 15: A repeater (10) for controlling the digital signal to be stored in the memory (18) or output to the communication port (19) by the microcomputer (16); And a signal transmitted from the communication port 19 of the repeater 10 to the main body 21 through the communication line 30, and displays a predetermined calculation result on the monitor 22 according to the input selection of the keyboard 23. Characterized in that it comprises a personal computer 20 to output to.

At this time, the microcomputer 16 of the repeater 10 periodically performs data transmission to the communication port 19, sets up data required by a selected function upon inputting a setting command, and backs up the data to the memory 18.

The main body 21 of the personal computer 20 periodically updates the calculation result on the monitor 22 and transmits the result to the microcomputer 16 of the repeater 10 after performing the corresponding work when the setting mode is input. .

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

1 is an exemplary diagram showing a schematic configuration of a device according to the present invention, and FIG. 2 is a block diagram showing a circuit configuration for main functional parts of the device according to the present invention.

The load cell 12, which is installed to be mechanically connected to the lower end of the weighbridge 11, is electrically connected to the amplifier 13, the low pass filter 14, the A / D converter 15, and the like. The microcomputer 16 having a microprocessor is connected to control the amplifier 13, the low pass filter 14, and the A / D converter 15 through the control logic 17. The memory 18 backs up the autozero adjustment function, span adjustment calibration data, and the like, and uses nonvolatile RAM memory (NVRAM) to store necessary data even when the power supply is cut off. The microcomputer 16 includes a communication port 19, which is a serial bidirectional port, and an RS232C buffer IC to enable digital bidirectional communication. The communication port 19 is connected to the main body 21 of the personal computer 20 through the RS232C communication line 30. The personal computer 20 includes a monitor 22 for displaying a result by executing predetermined software, a keyboard 23 for inputting various commands, a speaker for processing input data, and generating various processes as a multimedia function ( 24).

Accordingly, the mechanical force of the load applied to the weighbridge 11 is converted into an electrical weight signal in the load cell 12 sensor, which is a load sensor, which is an amplifier 13, a low pass filter 14, and an A / D converter 15. Is converted into a digital signal, and the microcomputer 16 performs a stabilization process and a digital communication function of the weighing signal and is transmitted to the personal computer 20 in the form of RS232C. The personal computer 20 receives the transmitted weight data, executes a predetermined software program, displays the weight value on the monitor 22, and then stores, records, and processes information according to each software function.

On the other hand, since the two-way digital communication function is possible, the function of controlling the microcomputer 16 using a command reversely from the personal computer 20 side is also possible. Accordingly, through the signal processing circuit of the repeater 10, various compensation functions such as temperature compensation of the measured value according to the temperature change of the load cell 12 and calibration functions such as span adjustment function can be performed.

The software in the present invention is largely divided into the repeater 10 side software for the A / D interface by the microcomputer 16 and the personal computer 20 side software for monitor screen display and two-way communication. If most of the processing is configured to be possible on the repeater 10 side, the repeater 10 may have the function of an independent indicator controller alone. When the microcomputer 16 of the repeater 10 is initialized, various flags used for A / D conversion are initialized and operate in the mode according to the instruction of the personal computer 20 side. The operation according to this is divided into a normal mode and a setup mode as described below.

3 shows a flowchart illustrating the operation of a repeater in an apparatus according to the invention.

In the normal mode for performing normal weighing, the digital weight data converted from the A / D converter 15 is transferred to the personal computer 20 through the communication port 19 after the internal stabilization signal processing, and operated in conjunction with the software of FIG. 4. Let this be done. In the setting mode, various initialization and calibration are performed by the command received from the personal computer 20, and the data necessary for the selection of the weighing capacity, the resolution selection, the span adjustment function, and the various automatic compensation functions are set for each type, and the memory is stored. The function of backing up to 18 is performed.

At this time, it is possible to set the maximum weighing capacity, the minimum display weight, the daily change curve of the weight, and the memory display function of the previous weighing value.

In more detail, in FIG. 3, the controller first determines whether it is the setting mode, and if yes, processes the setting mode, and if no, reads the A / D conversion data in the normal mode and goes through a nonlinearity correction algorithm of the sensor when stable data comes in. Performs a function of transmitting / D data according to a command of the personal computer 20 side.

At this time, the function of the one chip microprocessor (ATMEL 89C52), which is a CPU built in the microcomputer 16 of the repeater 10, is a dual-integrated A / D conversion controlled by an analog switch and drift of an analog circuit. Value stabilization and compensation, two-way digital serial communication, auto-zero tracking, anti-flickering, linearity compensation, etc. Perform internal calculations and multi-range, store and update calibration data in memory (EEPROM), decode and process instructions received from load cell 12 or personal computer 20, load cell 12 Nonlinearity correction algorithm.

In the A / D interface, one command frame is composed of 11 bytes or 12 bytes, and the command exchanges commands and data with the personal computer 20 using an ASCII code command composed of 1 byte or 2 bytes.

As an example of the main command of the A / D interface, the 'I' command initializes flags such as StartZeroFlag, RxEnableFlag, InitialFlag, ZeroFlag, and CountendFlag in normal mode. At this time, RxEnableFlag indicates that the PC command can be received after initializing the A / D interface, and InitialFlag initializes the A / D interface and initializes the InitialFlag by the Initialize function after power-on. . This flag is checked and notified to the PC that it has been initialized. ZeroFlag is set when the zero is within the range and used to set the zero. CountendFlag is set when the A / D conversion is completed to indicate the end of the count. .

In addition, 'R' command sends version information, 'D' command sends A / D data, 'F' command sends capacity data, '*' command switches to test mode, 'I' command ends test mode, 'S' 'Command to set all data initial values,' Z 'command to zero adjustment,' T 'command to span adjustment,' L 'command to adjust nonlinearity,' X 'command to set the weight sensor capacity, and' W 'command Is set data storage, the 'U' instruction is set to command the storage data output.

4 is a flowchart showing the operation of the personal computer in the apparatus according to the present invention.

The personal computer 20 determines the presence or absence of a setting command by the user and performs a corresponding operation in the setting mode, sends a command for setting up the data, and transmits the command to the microcomputer 16. The A / D conversion digital data input from the repeater 10 is divided into the corresponding display mode (normal display, counting display, historical history change graph indicator), displayed on the monitor 22, and continuously waiting for display switching input. Done. Here, the normal weighing display is an operation of weighing the weight as a general scale weighing machine, and the counting display is a total weight displaying operation of the unit price when used for commercial use, and the past history change is the last time when used as a scale or a weight checker. ) Display of comparison record with weighing value.

The communication specifications of the personal computer 20 are set to 19200, E, 7, 1 / baud: 19200 / parit: NONE / data bits: 7 bits / stop bits: 1. The functions of the personal computer 20 are divided into the communication port initialization, command processing, error (err) processing, initial value determination, weight indication conversion, graph display, A / D interface specification setting, and the like.

The main screen output stage contains A / D interface, communication port setting, setting function, and main menu to save screen. In addition, after entering the normal mode, the setup mode menu is entered to enter the pop up menu prepared for entering the setup mode and to send a command to change or save the specifications of the A / D interface in the setup mode. have.

Next, the communication initialization and A / D initialization step, the microcomputer 16 receives the initialization command from the personal computer 20 performs an initialization operation for its own A / D conversion while error of its own error The message is sent to the personal computer 20 together with the message. The personal computer 20 may check whether there is an error in the A / D interface through an error message.

Next, the range check step checks whether the A / D conversion data is within the reference zero value range, and at the same time, the effective range of the data at various stages such as span control, linearity compensation, and calibration. Check the range.

Next, the load cell 12 may cause a slight change in the characteristics of the sensor over time. When the characteristic or state of the sensor falls within the setting range, the load cell 12 corrects the minute change of the reference zero value. After the calibration step, it is necessary to remember the weight value when the work is terminated and the power is cut off, so it is also stored.

Next, in normal mode, the A / D interface converts the A / D converted data from the sensor into a weight value and processes various functions as a normal operation for A / D conversion of the analog signal from the load cell 12 sensor. The process is included. Setup Mode Various menus for controlling the A / D interface such as auto span adjust, linearity compensation, zero set, scale change, receive & send, etc. Is ready. The changed data is stored in the memory 18. The command sent to and received from the A / D interface of the repeater 10 is composed of a frame having a certain format. However, because the length of the frame varies depending on the data sent and received, check whether the frame corresponding to the sent command has arrived.

The next step is to initialize the segment, which handles what is displayed in normal mode and setup mode and stores the A / D converted values. There are two methods for observing the variation of the load cell 12 sensor. The first is to trace the change, and the other is to compare with the reference value. When the comparison value is out of the indicated value, it changes the graph color and remembers the previous value.

The final step is to initialize the A / D interface and then send a command requesting the A / D converted value. Instead of sending the A / D converted data directly from the sensor, the A / D interface goes through the process of checking the range of data, correcting the linearity, checking the error, etc., and then sends a constant A / D converted value to the personal computer (20). (20) processes this through the initial value processing and the weight conversion process. The A / D converted digital value is calculated by weight in Kg, g and the like and rounded.

5 is a screen state diagram showing a pop-up menu in the normal mode according to the present invention, Figure 6 is a screen state diagram showing a pop-up menu in the setting mode according to the present invention.

In the top menu, there is a part that sets the value of the communication port, a setting function, and a main program that receives data from the A / D interface and converts it into a weight value. Normal mode is initiated by a hotkey or menu selection and initially initializes the communication port to 19200. At this time, the personal computer 20 sends an initialization command to the A / D interface, requests an A / D value when the received data normally arrives, and outputs an error message when an error occurs. When referring to the screen appearing on the monitor 22, in the normal mode, the upper left number indicates the A / D value converted into weight, and the upper right number indicates the weight value read last time or changed by setting. Display the value.

In the lower part of the screen output, a multi-color graph is displayed. The change is tracked so that the overall variation width of the sensor's A / D value can be easily observed, and the color changes when the change amount exceeds a predetermined value.

Functions of setting mode include linear correction command, zero adjustment and span adjustment command. Linear correction command must be performed after zero and span adjustment. After applying the weight corresponding to the linear correction command 'L1', send the 'L1' command to the A / D interface. When prompted to add weight, add the weight that corresponds to the first point; when prompted, remove the weight. Next, the commands 'L2', 'L3', 'L4', and 'L5' are operated like 'L1'. After the final value has been performed, the calculated value is stored in the memory.

According to the above configuration and operation, the present invention has an effect of displaying and observing the weight and health state associated with it at any time by simply connecting to a personal computer widely distributed in a home or office, and storing and managing records.

Claims (3)

In a repeater which digitally processes an analog signal generated from the load cell 12 by an amplifier 13, a low pass filter 14, and an A / D converter 15, and converts the digital signal into: A repeater (10) for controlling the digital signal to be stored in the memory (18) or output to the communication port (19) by the microcomputer (16); And The signal is transmitted from the communication port 19 of the repeater 10 to the main body 21 through the communication line 30, and a predetermined calculation result is output on the monitor 22 according to the input selection of the keyboard 23. Repeater using a personal computer characterized in that it comprises a personal computer (20) to output. The method of claim 1, The microcomputer 16 of the repeater 10 periodically performs data transmission to the communication port 19 and sets up data required by a selected function upon inputting a setting command and backs up the data to the memory 18. Weighing device using personal computer. The method of claim 1, The main body 21 of the personal computer 20 periodically updates the calculation results on the monitor 22 and transmits the results to the microcomputer 16 of the repeater 10 after performing the corresponding work when the setting mode is input. Weighing device using a personal computer, characterized in that.