Specification of Digital Watch Behaviour using Statecharts
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General Information
GoalsThis assignment will make you familiar with Statechart modelling, simulation, and code synthesis (and a bit of testing). Problem statementIn this assignment, you will design a Statechart model specifying the reactive behaviour of a Digital Watch (inspired by the 1981 Texas Instruments LCD Alarm Chronograph). You will first model the reactive behaviour of the watch in the DCharts formalism (a variant of Statecharts) in the tool AToM3. The Statechart simulator SVM (as a plugin of AToM3) will allow you to check, by means of simulation, whether your model behaves according to the requirements. Note that it is good practice to start modelling and trying out (after simulation and subsequently, code synthesis) small parts of the desired behaviour in isolation. These can be saved and later loaded to build the full solution Statechart. The model (saved as DigitalWatchStatechart_DCharts_MDL.py) and its visual representation must both be included in your index.html solution page. The visual representation is obtained by printing the model to file in Postscript format from AToM3 as DigitalWatchStatechart_DCharts_MDL.eps and subsequently converting it to a bitmap (e.g., DigitalWatchStatechart_DCharts_MDL.gif). Alternately, you can print the model to file in SVG (Scalable Vector Graphics) format as DigitalWatchStatechart_DCharts_MDL.svg and include it as such in your solution (as browsers such as Firefox now support SVG). The application's reactive behaviour (Python code) will be synthesized from the Statechart. The software application (DigitalWatch.py) is composed of a static component, a controller, and a dynamic component. The static component (DigitalWatchGUI.py) implements the visual aspects of the watch such as buttons, the display and the Indiglo light and organizes them into a graphical user interface (built using Tkinter, the standard Python interface to the Tk GUI toolkit). The dynamic component (DigitalWatchStatechart_DCharts_MDL_Compiled.py) will be automatically generated from your Statecharts model. This is done by pressing the "Generate .des" button in AToM3, saving your model as a .des file, and continuing to compilation with the default parameters -l tkinter. The communication between the static and the dynamic components is handled by the controller (found in DigitalWatchGUI.py). User events such as button press/release are passed from the GUI to the Statechart (as strings) by the controller. Conversely, the Statechart modifies the (visual) state of the GUI by invoking the controller's methods. Note that the Statechart receives a reference to the controller object as a parameter of the start event when, at application startup time, it goes from its initial state Setup to the state Running. (Behaviour) Requirements
To help clarify the requirements, the following contain a working solution (execOnly_32bit.zip and execOnly_64bit.zip). The Statechart model is only present in compiled form however. Note that these may work on your machine. Though Python source code is highly portable, the bytecode is not. Interface provided by the controllerbatteryHalf() Sets the battery power to half, making the display show only "8"s. batteryFull() Sets the battery power to full, making the display show as usual. getTime() Returns the current clock time. getAlarm() Returns the alarm time set. checkTime() Checks if the alarm time set is equal to the current clock time. If so, it will broadcast the "alarmStart" event to the statechart and return true. Otherwise, it returns false. Note that checkTime() does not care/check whether the alarm has been set "on". refreshTimeDisplay() Redraw the time with the current internal time value. The display does not need to be cleaned before calling this function. For instance, if the alarm is currently displayed, it will be deleted before drawing the time. refreshChronoDisplay See refreshTimeDisplay() refreshDateDisplay() See refreshTimeDisplay() refreshAlarmDisplay() See refreshTimeDisplay() resetChrono() Resets the internal chrono to 00:00:00. startSelection() Selects the leftmost digit group currently displayed on the screen. increaseSelection() Increases the currently selected digit group's value by one. selectNext() Select the next digit group, looping back to the leftmost digit group when the rightmost digit group is currently selected. If the time is currently displayed on the screen, select also the date digits. If the alarm is displayed on the screen, don't select the date digits. (to simplify the statechart). stopSelection() increaseTimeByOne() Increase the time by one second. Note how minutes, hours, days, month and year will be modified appropriately, if needed (for example, when increaseTimeByOne() is called at time 11:59:59, the new time will be 12:00:00). increaseChronoByOne() Increase the chrono by 1/100 second. setIndiglo() Turn on the display background light unsetIndiglo() Turn off the display background light setAlarm() Flag the alarm to be on or off. Events sent to the Statechart (as strings): (due to button press) - topRightPressed - topRightReleased - topLeftPressed - topLeftReleased - bottomRightPressed - bottomRightReleased - bottomLeftPressed - bottomLeftReleased (generated by checkTime() if current time == alarm time) - alarmStart Starting pointThe archive wristwatch.zip contains a very simple example to get you started. This starting point Statechart is reproduced here
The Models/DCharts/ folder in the central AToM3 installation contains some small examples demonstrating various features of Statecharts. The Models/DCharts/TrafficLight/ folder contains the small traffic light example (including the use of orthogonal components to model the "environment"). Practical informationPlease hand in any file that you modified. Include links to these files in your index.html. Also, please include your model as an image. DO NOT include files that weren't modified. It is good practice to model and simulate different parts of the overall solution in isolation (bottom-up design). You can save them in different files and later load them into a combined model. The scc Statechart compiler tries to produce speed-optimized code. This, at the expense of memory used. When you use too many orthogonal components this will lead to synthesized code which cannot be compiled/run. Hint: for the assignment, a "natural" solution will require 6 orthogonal components.
AToM3 is installed on the lab machines. There is extensive documentation on SVM and SCC. This is for example where you will find detailed information on macros (including on how to write your own). For those interested in more in-depth information on SVM and SCC, have a look at Thomas Feng's M.Sc. thesis. It is possible to install AToM3 and SVM/SCC on your own computer. They should run on (variants of) Windows, Linux, and Mac OS X (as long as Python/Tkinter is installed). Note that due to recent problems with Tkinter, there may be problems on Mac OS X. You need to download the latest version of AToM3 from http://atom3.cs.mcgill.ca/. You will need to download svm-0.3beta4-src.zip found on the same site. It contains SVM/SCC. It is best installed in the External/ directory of your central AToM3 installation. Alternately, it may be installed in your User External folder.
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