RU2402822C2 - Stand for studying microcontroller control systems - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: stand also includes a group of peripheral test and simulating devices, consisting of a source of harmonic signals with controlled amplitude and frequency, a source of pulsed signals with controlled frequency and pulse ratio, a potentiometre and a first-order integrating RC circuit with variable parametres. Combinatorial functions of the stand are provided by presence of a connecting field, one group of leads of which is connected to microcontroller leads, while the other groups of leads are connected to leads of user interface devices and to leads of test and simulating devices. Leads belonging to all groups can be connected to each other in given combinations using detachable electroconductive jumpers and can also be connected to external stands and contact calipers of external measurement and testing apparatus.

EFFECT: broader functional and combinatorial capabilities of the stand.

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Description

The invention relates to teaching aids and is hardware for the learning process in the development of microcontroller control systems.

The invention is a radio engineering device and can be used in the development of both software and hardware components of microcontroller control systems.

Based on the features of the development of microcontroller control systems, stands designed for their study should provide the ability to build and debug not only the software component of the system, but also the corresponding hardware component. For this, the interaction of the stands with a personal computer, the availability of various types of signal sources, a set of input and output information devices, and the ability to switch these devices between themselves and with the control microcontroller must be provided.

Based on the features of the construction of the learning process, it is necessary to ensure a consistent passage through all stages of the development of microcontroller control systems in a single software package, as well as the possibility of implementing an electrical circuit and joint debugging of the corresponding control program executed on the microcontroller. In addition, it is necessary to ensure the possibility of observation and analysis of the processes occurring in the system.

Known stands for training in the construction of electrical circuits, having a typesetting field for installing elements, allowing you to collect the circuit and conduct debugging. Such stands include, for example, a training stand for studying the basics of digital electronics, described in [1] - RU No. 2214628 (C2), G09B 23/18, publ. 10/20/2003. It also relates to teaching aids and allows the assembly and study of electronic circuits, to improve the skills of troubleshooting in electrical and electronic devices. The stand has a type-setting field with sockets for connecting electronic elements. The capabilities of this stand are limited to the study of electrical circuits that do not include programmable elements in the form of microcontrollers.

For the study of physical processes occurring in electrical circuits, and a detailed study of the level of hardware support for calculations, the stands are equipped with instrumentation. Such stands include, for example, a training stand on electronics, described in [2] - RU No. 2067779 (CI), G09B 23/18, publ. 10/10/1996. It contains a sweep of the time axis of the displayed signals and includes a multi-channel oscilloscope.

The capabilities of this stand are also limited by the study of electrical circuits that do not include programmable elements in the form of microcontrollers.

Studying the principles of programming microcontrollers allows the stand for teaching elements of digital electronics, described in [3] - RU No. 2002111521 (A), G09B2 3/18, publ. 11/10/2003. It contains a personal computer and a microcontroller emulator. The advantage of this stand is its high information content due to the possibility of registering a large amount of intermediate information. However, the microcontroller emulator does not allow you to explore various circuitry solutions and the possibilities of hardware interaction with external control objects and sensors.

Typical examples of emulators are in-circuit emulators described in [4] - RU No. 2110833 (C1), G06F 9/44, publ. 05/10/1998 and [5] - RU No. 2214621 (C2), G06F 9/455, publ. 10/20/2003. In-circuit emulators contain a design system interface unit, an address and control register block, a write / read control unit, a debugged program memory unit, a bus switch, a firmware control unit, a command generation unit, and a control panel unit.

An advantage of the in-circuit emulators described in [4, 5] is the ability to emulate a certain range of microcontroller families, for example, MCS-48, MCS-51, UP 1-42, which allows the use of emulators for debugging the software part of control systems containing data microcontrollers. However, the use of emulators limits the possibilities of modeling and debugging the hardware component of microcontroller control systems. In addition, the above stands do not include a switching field and peripheral units that facilitate the construction of microcontroller-based control systems.

To the greatest extent, the requirements for the stand for studying microcontroller control systems are met by the SDK-1.1 stand selected as a prototype, developed by the research and production company LLC LMT, St. Petersburg, http://lmt.ifmo.ru, structure and description which are presented, in particular, in the article [6] - A. Lukichev Expanding the capabilities of the laboratory complex SDK-1.1 // Scientific and Technical Bulletin of SPbGITMO (TU). Issue 10. Information and management in technical systems. - SPb .: SPbGITMO (TU), 2003. P.86-90.

A stand for studying microcontroller control systems, selected as a prototype, contains a controller board on which a microcontroller is installed, a read-only memory device used to store software, a random-access memory device used to store operational data, and a data transfer interface converter used for communication with external devices, as well as a group of user interface devices, consisting of a keyboard unit and an indication unit, inextricably linked Defining output of the microcontroller.

The microcontroller in the prototype booth uses the ADuC812 microcontroller of the MCS-51 family with built-in Flash memory, which functions as a permanent storage device.

The stand is connected to the external information exchange network through a converter of the data transmission interface using the RS232C protocol. The microcontroller communicates with the instrumental computer via an external information exchange network, on which the debugged program for the microcontroller is prepared and loaded.

The group of user interface devices contains a matrix keyboard unit, switches that enable manual supply of constant voltages to certain inextricably linked outputs of the microcontroller, as well as an indication unit, which is a liquid crystal symbol indicator and a set of signal LEDs.

Structurally, the stand is made in the form of a printed circuit board and has contacts with screw clamps for connecting external signal sources, and also has means providing the ability to connect to an external information exchange network.

Work with the prototype booth is as follows.

The stand is connected to an external instrumental computer, on which debugged software is prepared and loaded into the permanent storage device, which must correspond to a predetermined circuit for connecting the outputs of the microcontroller to the keyboard, switches, liquid crystal display and LEDs. Next, the signals at specific pins of the microcontroller and their timing diagrams are examined. By making corrections to the debugged software or replacing it with a new one, the changes in the monitored signals are investigated in this case.

Thus, the prototype booth allows you to study microcontroller control systems with an unchanged, rigidly laid configuration of communications between the microcontroller and peripheral devices.

In the prototype booth, it is not possible to change the configuration of the connections between the microcontroller and peripheral devices, in addition, the set of peripheral devices itself does not allow simulating a wide range of input influences that are often designed to process real microcontroller control systems. In addition, system software that provides loading and debugging is stored in Flash memory, which allows accidental damage by incorrectly functioning debugged software. The design of the stand in the form of a printed circuit board, on which both electronic components and mechanical switches and contacts with screw clamps are located, does not provide protection against accidental mechanical or electrostatic damage to its elements. All this limits the functional and combinatorial capabilities of the stand for the study of microcontroller control systems, and also reduces the reliability characteristics.

The technical problem to be solved by the claimed invention is directed is the development of a stand for studying microcontroller control systems that provides advanced functional and combinatorial capabilities in the study, development and debugging of microcontroller control systems.

The essence of the invention lies in the fact that the stand for the study of microcontroller control systems, comprising a controller board on which a microcontroller is installed, a read-only memory device used to store software, a random access memory device used to store operational data, and a data transmission interface converter serving for communication with external devices, as well as a group of user interface devices consisting of a keyboard unit and an indication unit, add It contains a group of peripheral test and simulating devices, consisting of a source of harmonic signals with adjustable amplitude and frequency, a source of pulse signals with adjustable frequency and duty cycle, a potentiometer and an integrating first-order RC link with variable parameters, as well as a switching field, the first group of conclusions of which connected to the outputs of the microcontroller, the second group of outputs connected to the outputs of the specified user interface devices, and the third group of outputs connected to the findings specified test and simulating devices. At the same time, the conclusions belonging to all three of the indicated groups are made with the possibility of connecting to each other in predetermined combinations using removable conductive jumpers and connecting external stands and contact probes to external control and measuring partitions to them.

System software is stored in read-only memory, which is made in the form of a memory chip with ultraviolet erasure of information. This avoids accidental damage to system software by malfunctioning debugging software.

Structurally, the stand is made in the case in the form of a desktop monoblock, which serves to provide protection against accidental mechanical and electrostatic damage to its elements.

The invention and its feasibility are illustrated by the structural diagram presented in the drawing.

A stand 1 for studying microcontroller control systems (hereinafter referred to as a stand) comprises a board 2 on which a microcontroller 3 is installed, a read-only memory 4 used to store system software, and a read-only memory 5 used to store operational data and a debugged program, and a data transmission interface converter 6, which is used for communication with an external information exchange network, as well as a switching field 7, a group of 8 peripheral test and simulating devices, consisting of and a source of 9 harmonic signals with adjustable amplitude and frequency, a source of 10 pulse signals with an adjustable frequency and duty cycle, a potentiometer 11 and an integrating first-order RC link 12 with variable parameters, as well as a group 13 of user interface devices consisting of a matrix keyboard 14 and a liquid crystal character indicator 15.

The switching field 7 has three groups of pins 16, 17 and 18. The first group of pins 16 is inextricably linked to the pins of the microcontroller 3. The second group of pins 17 is inextricably linked to the pins of group 13 of user interface devices. The third group of conclusions 18 is inextricably linked with the conclusions of group 8 of peripheral test and simulating devices. At the same time, the conclusions belonging to all three groups 16, 17 and 18 are made with the possibility of connecting to each other in predetermined combinations using removable conductive jumpers (not shown in the drawing) and connecting to them contact probes of external instrumentation 19 and external stands twenty.

Stand 1 is made with the possibility of choosing the connection to the instrumental computer 21 or external stands 22 through the Converter interface data transfer 6 protocol RS232C.

As the microcontroller 3 in the inventive stand, in the preferred embodiment, the microcontroller of the company Infineon SAB 80C535 of the MCS-51 family is used. Permanent storage device 4 is made in the form of a memory chip with ultraviolet erasure of information. This embodiment of the storage device 4, in contrast to the prototype using Flash-memory, significantly increases operational reliability in the educational process.

Structurally, stand 1 is made in the form of a desktop monoblock that protects the internal elements of stand 1 from accidental mechanical and electrostatic damage. The monoblock is made with the possibility of visual inspection of the elements of the stand 1 through a transparent window on the front panel.

The matrix keyboard 14 and the LCD panel 15 are located on the front panel of the stand 1. In addition, on the front panel there are controls for the source 9 harmonic signals with adjustable amplitude and frequency, controls for the source 10 pulse signals with adjustable frequency and duty cycle, controls for the potentiometer 11 and an integrating RC link 12 of the first order with variable parameters.

The front panel also displays the sockets of all three groups of terminals 16, 17 and 18 of the switching field 7, which are used to connect removable conductive jumpers and contact probes of external instrumentation 19 and external stands 20.

Work with the inventive stand is as follows. In accordance with the task to be solved, a circuit diagram of the connections of the terminals of the microcontroller 3, the outputs of the peripheral test and simulating devices from group 8, the outputs of the user interface devices from group 13, as well as the contact probes of the external measuring instruments 19 and external stands 20. This circuit is assembled on switching field 7 using removable conductive jumpers, connecting in the desired combination of terminals of groups 16, 17 and 18 of the switching field 7. Using an external instrumental computer 21 debugged software is prepared, which is then downloaded via external data exchange network to random access memory 5. At the same time, the system software stored in read-only memory is used 4. Next, the state of the microcontroller system is examined using system software and instrumentation 19 , signals at specific pins of the microcontroller and their timing diagrams. By making corrections to the debugged software or replacing it with a new one, the changes in the monitored signals are investigated in this case.

At the same time, unlike the prototype, the inventive stand additionally allows you to acquire the skills of building electrical circuits necessary for the development of microcontroller control systems and to study the processes occurring in the microcontroller control system, with an expanded set of peripheral devices interacting with the microcontroller.

The applied solutions provide new functional and combinatorial capabilities of the stand for studying microcontroller control systems, as well as improve its operational characteristics, making it possible to bring the development of microcontroller control systems as close as possible to reality, ensuring reliable operation and ease of understanding of the processes occurring in the system.

Thus, it follows from the foregoing that the claimed invention is technically feasible and ensures the achievement of a technical result, which consists in creating a stand for studying microcontroller control systems, which, in comparison with the prototype, has fundamentally different functional and combinatorial capabilities in the study, development and debugging of microcontroller systems control, allowing you to debug the software part together with the hardware part of the microcontroller being developed with Stem management and thus to enhance the effectiveness of the process of training specialists in the development of microcontroller control systems.

Information sources

1. RU No. 2214628 (C2), G09B 23/18, publ. 10/20/2003.

2. RU No. 2067779 (CI), G09B 23/18, publ. 10/10/1996.

3. RU No. 2002111521 (A), G09B 23/18, publ. 11/10/2003.

4. RU No. 2110833 (CI), G06F 9/44, publ. 05/10/1998.

5. RU No. 2214621 (C2), G06F 9/455, publ. 10/20/2003.

6. Lukichev A.N. Expanding the capabilities of the laboratory complex SDK-1.1 // Scientific and Technical Bulletin of SPbGITMO (TU). Issue 10. Information and management in technical systems. - SPb .: SPbGITMO (TU), 2003. P.86-90.

Claims (3)

1. A stand for studying microcontroller control systems, comprising a controller board on which a microcontroller is installed, a read-only memory device used for storing software, a read-only memory device used for storing operational data, and a data interface converter that is used to communicate with external devices as well as a group of user interface devices consisting of a keyboard unit and an indication unit, characterized in that the stand further comprises a group of peripheral test and simulating devices, consisting of a source of harmonic signals with adjustable amplitude and frequency, a source of pulse signals with adjustable frequency and duty cycle, a potentiometer and RC-link with variable parameters, as well as a switching field, the first group of conclusions of which is connected to the outputs of the microcontroller, the second group of conclusions is connected with the conclusions of the specified user interface devices, and the third group of conclusions is connected with the conclusions of the specified test and simulating devices, p and this conclusions belonging to all three of these groups, is configured to interconnect in predetermined combinations using removable conductive jumpers and connect to external stands and external contact probe control and measurement partings. 2. The stand according to claim 1, characterized in that the system software is stored in a read-only memory made in the form of a memory chip with ultraviolet erasure of information. 3. The stand according to claim 1, characterized in that it is structurally made in the housing in the form of a desktop monoblock.