We performed a simulation of our project in PROTEUS. Proteus* is a software technology that allows creating clinical executable decision support guidelines with little effort.
Proteus is best simulation software for various designs with microcontroller. It is mainly popular because of availability of almost all microcontrollers in it. So it is a handy tool to test programs and embedded designs for electronics hobbyist. 19
Proteus is a software package for computer-aided design, simulation and design of electronic circuits. It consists of two main parts, the ISIS, the circuit design environment that even the simulator VSM includes, and the ARES, the PCB -Designer. The components are:
We are using ISIS which is explained as follows:
The ISIS, Intelligent Schematic Input System (Intelligent Switching Input System) is the environment for the design and simulation of electronic circuits. The component library includes claims to more than 10,000 circuit components with 6000 Prospice simulation models. Own components can be created and added to the library.
ISIS includes a base-VSM engine with support for the following functionality:
• DC/AC-Volt- & Amperemeter
• Digital Pattern Generator
• ( RS232, I2C, SPI)
After Simulating the circuit in Proteus Software , PCB design can be direcly made with it so it could be a all in one package for students and hobbyists. Proteus combines advanced schematic capture, mixed mode SPICE simulation, PCB layout and auto-routing to make a complete electronic design system.
ISIS provides the development environment for PROTEUS VSM, our revolutionary
interactive system level simulator. This product combines mixed mode circuit simulation,
micro-processor models and interactive component models to allow the simulation of
complete micro-controller based designs.
ISIS provides the means to enter the design in the first place, the architecture for real time
interactive simulation and a system for managing the source and object code associated with
each project. In addition, a number of graph objects can be placed on the schematic to enable
conventional time, frequency and swept variable simulation to be performed.
Major features of PROTEUS VSM include:
· True Mixed Mode simulation based on Berkeley SPICE3F5 with extensions for digital
simulation and true mixed mode operation.
· Support for both in teractive and graph based simulation.
· CPU Models available for popular microcontrollers such as the PIC and 8051 series.
· Interactive peripheral models include LED and LCD displays, a u niversal matrix keypad,
an RS232 terminal and a whole library of switches, pots, lamps, LEDs etc.
· Virtual Instruments include voltmeters, ammeters, a dual beam oscilloscope and a 24
channel logic analyser.
· On-screen graphing – the graphs are placed directly on the schematic just like any other
object. Graphs can be maximised to a full screen mode for cursor based measurement
and so forth.
· Graph Based Analysis types include transient, frequency, noise, distortion, AC and DC
sweeps and fourier transform. An Audio graph allows playback of simulated waveforms.
· Direct support for analogue component models in SPICE format.
· Open architecture for ‘plug in’ component models coded in C++ or other languages.
These can be electrical., graphical or a combination of the two.
· Digital simulator includes a BASIC-like programming language for modelling and test
· A design created for simulation can also be used to generate a netlist for creating a PCB
there is no need to enter the design a second time.
3.2.1 SIMULATION IN PROTEUS
Simulation in proteus consists of different steps which involves making of circuit, drawing schematic on proteus, selecting components, writing program, assembling and compilation, debugging of program and converting it into hex file. Then schematic is run to check results of simulation.
18.104.22.168 THE CIRCUIT
The circuit to be simulated is shown here, consisting of a PIC 16F877 microcontroller unit (MCU), input push buttons and output LEDs which will display a binary count. An external adjustable CR clock circuit is used. The push buttons are not used in the simple program BIN1. Make a folder to hold the project files called BIN1. Schematic will look like Fig 3.6:
Fig 3.6 SAMPLE CIRCUIT
22.214.171.124 THE SCHEMATIC
The ISIS user interface is shown here, consisting of edit, overview and object select windows, with edit toolbars. Components are added to the object list from the libraries provided, dropped onto the schematic, and connected up using virtual wiring. Components can be labeled and their simulation properties modified. Save the schematic as BIN1.DSN in the project folder. Saved schematic is shown in Fig 3.7 below:
Fig 3.7 SAMPLE SCHEMATIC
126.96.36.199 SELECT COMPONENTS
Components are found in the libraries accessed via the ‘pick’ button P in the object select window. The MCU is selected from ‘Microprocessors ICs’ category, ‘PIC16 Family’ sub-category. The other components are added to the pick list from the appropriate categories. These are then selected and dropped on the schematic within the blue border. This is shown in Fig 3.8 below:
Fig 3.8 SELECTING COMPONENTS
Welcome to the Easy-PC Schematic and PCB design system. The system is built on an integrated design environment providing all the tools required to capture a schematic and simulate it using the SPICE based analogue/digital simulator, through to the design and layout of the printed circuit boards (PCBs). This is aided with a 32 bit auto router and various options. 18
3.1.1 SYSTEM REQUIREMENTS
Easy-PC runs under the Windows operating systems but it is recommended that Windows 7 or Windows 8 is used. It cannot run under Windows 3.1x, Linux or MAC. A Pentium processor with plenty of memory installed should be used. Easy-PC does not require particularly ‘high powered’ hardware to achieve good performance, a regular off-the-shelf PC should be sufficient. A complete product installation requires at least 190Mb of hard drive space. A mouse with a mouse wheel is recommended and a CD-ROM drive or an internet connection is required to load the product from CD or from our web site.
It is assumed that the Easy-PC product or demo is successfully installed onto the computer. If it doesnot exist, then use the product CD or a download from the numberone.com web site. The installation is straight forward using the wizard provided. Follow the instructions and use the default settings provided. The tutorial designs can be run even using Easy-PC in demo mode if the demonstration version is being used. Note, the demo version and full product are not the same, the demo cannot be ‘converted’ to a full version, it requires a new installation.
3.1.3 STARTING EASY-PC
During installation, an Easy-PC program group added to the Start menu, under Programs then Number One Systems. To start Easy-PC, simply select the Easy-PC menu item. When you run Easy-PC, the main application window appears. It, can open any number and combination of different designs and libraries together in this.
Easy-PC is installed with a set of commonly used toolbars to use. These tools can be fully customized to design practice once one become familiar with the product. All the toolbars can be seen in Fig 3.2.
Fig 3.2 TOOLBARS
As well as the status bar information and Properties dialog, by hovering the mouse over a design item, information about that item will be instantly revealed on a design tooltip.
Fig 3.3 INFORMATION OF DESIGN ITEM
3.1.5 STARTING A NEW SCHEMATIC
? To start a new Schematic design
On the File menu, click New and Schematic Design from the Design tab. Consider Fig 3.4:
Fig 3.4 CREATING NEW DESIGN
Click the OK button to start a new Schematic design.
Easy-PC window will look like Fig 3.5:
Fig 3.5 EASY-PC WINDOW
3.1.6 ADDING COMPONENTS
It can be used two methods to add components; by using the Add Component option and using the Add Component Browser. For this tutorial,the Add Component Browser will be used.
? To add a Component
The Add Component Browser bar has automatically been run when it started a new Schematic design. Select components as required for the design.
3.1.7 ADDING CONNECTIONS
Connections are added to the Schematic design to make connectivity between electrical pins. When translated to the PCB design, these connections give the net list. By adding a connection when start this tutorial, default properties are already set up. All the need to do is add the connection. Later on as one become more familiar with Easy-PC, one can change and customize the connection properties to it own settings.
Connections are added in a number of ways:
• Using the Add Connection option from the Add menu or from the Schematic Toolbar, click on the pin to start adding a connection.·
• Double-clicking on a component pin to start a new connection.
• ‘Dragging’ off an unconnected component pin to start a new connection.
3.1.8 ADDING POWER & GROUND SYMBOLS
Power and ground symbols are used in the Schematic to indicate a connection to a power source. These symbols are required for aesthetic purposes and are not translated to the PCB (because they do not have PCB footprints associated with them). The signals they represent are connected together at the translate stage by ‘implied’ connectivity. The power & ground symbols themselves can contain inherent net name properties that are automatically used when the symbol is attached to the net.
3.1.9 ROUTING THE DESIGN
The design can be routed manually or automatically. This is the process of converting the electrical point-to-point connections into physical copper ‘tracks’. Initially we will route the design manually. Easy-PC has a set of powerful manual routing tools to aid this process. These tools allow you to swap layers, automatically add vias on layer swaps and edit track thickness.