As the revised diagram in Figure \ref{block_diagram_final.png} shows, to remove an extra layer of complexity it was decided to use a single device (the BeagleBone Black) to play the role of both the experiment server and the embedded device. From a software perspective, this eliminated the need for an entire layer of communication and synchronization. From a hardware perspective, use of the BeagleBone black instead of a Raspberry Pi removed the need to design or source analogue to digital conversion modules.
-Another major design change which occured quite early in the project is the switch from using multiple processes to running a single multithreaded process on the server. After performing some rudimentary testing (see Section \ref{Server Interface}) it became clear that a system of seperate programs would be difficult to implement and maintain. Threads are similar to processes but are able to directly share memory, with the result that much less synchronisation is required in order to transfer information.
+Another major design change which occurred quite early in the project is the switch from using multiple processes to running a single multithreaded process on the server. After performing some rudimentary testing (see Section \ref{Server Interface}) it became clear that a system of separate programs would be difficult to implement and maintain. Threads are similar to processes but are able to directly share memory, with the result that much less synchronisation is required in order to transfer information.
{\bf Note on filenames:} In the following, files and directories related to the server are located in the \href{https://github.com/szmoore/MCTX3420/tree/master/server}{server} directory, files related to the (currently used) GUI are in \href{https://github.com/szmoore/MCTX3420/tree/master/testing/MCTXWeb}{testing/MCTXWeb}, and files created for testing purposes are located in \href{https://github.com/szmoore/MCTX3420/tree/master/testing}{testing}.
\end{enumerate}
-In reality, threads do not run simultaneously; the operating system is responsible for sharing execution time between threads in the same way as it shares execution times between processes. Because the linux kernel is not deterministic, it is not possible to predict when a given thread is actually running. This renders it impossible to maintain a consistent sampling rate, and necessitates the use of time stamps whenever a data point is recorded.
+In reality, threads do not run simultaneously; the operating system is responsible for sharing execution time between threads in the same way as it shares execution times between processes. Because the Linux kernel is not deterministic, it is not possible to predict when a given thread is actually running. This renders it impossible to maintain a consistent sampling rate, and necessitates the use of time stamps whenever a data point is recorded.
Figure \ref{sample_rate_histogram.png} shows a distribution of times\footnote{The clock speed of the BeagleBone is between 200MHz and 700MHz (depends on power)\cite{cameon.net} which is fast enough to neglect the fact that recording the timestamp takes several CPU cycles} between samples for a test sensor with the software sampling as fast as possible. Note the logarithmic $t$ axis. Although context switching clearly causes the sample rate to vary (\textcolor{green}{green}), the actual process of reading an ADC (\textcolor{red}{red}) using \funct{ADC_Read} (\gitref{server}{bbb_pin.c}) is by far the greatest source of variation.
-It was not possible to obtain a real time linux kernel for the BeagleBone. In theory, real time variants of the linux kernel improve the reliability of sampling rates. However, testing on an amd64 laptop showed very little difference in the sampling time distribution when the real time linux kernel was used.
+It was not possible to obtain a real time Linux kernel for the BeagleBone. In theory, real time variants of the Linux kernel improve the reliability of sampling rates. However, testing on an amd64 laptop showed very little difference in the sampling time distribution when the real time Linux kernel was used.
\begin{figure}[H]
\subsection{Main Thread}\label{Main Thread}
-The main thread of the process is responsible for transfering data between the server and the client through the Hypertext Transmission Protocol (HTTP). A library called FastCGI is used to interface with an existing webserver called nginx\cite{nginx}. This configuration and the format of data transferred between the GUI and the server is discussed in more detail Section \ref{Communications}.
+The main thread of the process is responsible for transferring data between the server and the client through the Hypertext Transmission Protocol (HTTP). A library called FastCGI is used to interface with an existing webserver called nginx\cite{nginx}. This configuration and the format of data transferred between the GUI and the server is discussed in more detail Section \ref{Communications}.
-Essentially, the main thread of the process responds to HTTP requests. The GUI is designed to send requests periodically (eg: to update a graph) or when a user action is taken (eg: changing the pressure setting). When this is received, the main thread parses the request, the requested action is performed, and a response is sent. The GUI is then responsible for updating its appearance or alerting the user based on this response. Figure \ref{fastcgi-flow-chart.png} in Section \ref{API}gives an overview of this process.
+Essentially, the main thread of the process responds to HTTP requests. The GUI is designed to send requests periodically (e.g.: to update a graph) or when a user action is taken (e.g.: changing the pressure setting). When this is received, the main thread parses the request, the requested action is performed, and a response is sent. The GUI is then responsible for updating its appearance or alerting the user based on this response. Figure \ref{fastcgi-flow-chart.png} in Section \ref{API}gives an overview of this process.
\subsection{Sensor Threads}\label{Sensor Thread}
Figure \ref{sensor_thread.pdf} shows a flow chart for the thread controlling an individual sensor. This process is implemented by \verb/Sensor_Loop/ and associated helper functions.
-All sensors are treated as returning a single floating point number when read. A \type{DataPoint} consists of a time stamp and the sensor value. \type{DataPoint}s are continously saved to a binary file as long as the experiment is in process. An appropriate HTTP request (Section\ref{API}) will cause the main thread of the server program to respond with \type{DataPoint}s read back from the file. By using independent threads for reading data and transferring it to the GUI, the system does not rely on maintaining a consistent and synchronised network connection. This means that one the experiment is started with the desired parameters, a user can safely close the GUI or even shutdown their computer without impacting on the operation of the experiment.
+All sensors are treated as returning a single floating point number when read. A \type{DataPoint} consists of a time stamp and the sensor value. \type{DataPoint}s are continuously saved to a binary file as long as the experiment is in process. An appropriate HTTP request (Section\ref{API}) will cause the main thread of the server program to respond with \type{DataPoint}s read back from the file. By using independent threads for reading data and transferring it to the GUI, the system does not rely on maintaining a consistent and synchronised network connection. This means that one the experiment is started with the desired parameters, a user can safely close the GUI or even shutdown their computer without impacting on the operation of the experiment.
\subsection{Actuator Threads}\label{Actuator Thread}
-Actuators are controlled by threads in a similar way to sensors. Figure \ref{actuator_thread.pdf} shows a flow chart for these threads. This is implemented in \verb/Actuator_Loop/. Control over real hardware is seperated from the main logic in the same way as sensors (relevant files are in the \verb/actuators/ sub directory). The use of threads to control actuators gives similar advantages in terms of eliminating the need to syncronise the GUI and server software.
+Actuators are controlled by threads in a similar way to sensors. Figure \ref{actuator_thread.pdf} shows a flow chart for these threads. This is implemented in \verb/Actuator_Loop/. Control over real hardware is separated from the main logic in the same way as sensors (relevant files are in the \verb/actuators/ sub directory). The use of threads to control actuators gives similar advantages in terms of eliminating the need to synchronise the GUI and server software.
The actuator thread has been designed for flexibility in how exactly an actuator is controlled. Rather than specifying a single value, the main thread initialises a structure that determines the behaviour of the actuator over a period of time. The current structure represents a simple set of discrete linear changes in the actuator value. This means that a user does not need to specify every single value for the actuator. The Actuator thread stores a value every time the actuator is changed which can be requested in a similar way to sensor data.
\subsection{Data Storage and Retrieval}
-Each sensor or actuator thread stores data points in a seperate binary file identified by the name of the device. When the main thread receives an appropriate HTTP request, it will read data back from the binary file. To allow for selection of a range of data points from the file, a binary search has been implemented. Functions related to data storage and retrieval are located in the \gitref{server}{data.h} and \gitref{server}{data.c} source files.
+Each sensor or actuator thread stores data points in a separate binary file identified by the name of the device. When the main thread receives an appropriate HTTP request, it will read data back from the binary file. To allow for selection of a range of data points from the file, a binary search has been implemented. Functions related to data storage and retrieval are located in the \gitref{server}{data.h} and \gitref{server}{data.c} source files.
Several alternate means of data storage were considered for this project. Binary files were chosen because of the significant performance benefit after testing, and the ease with which data can be read from any location in file and converted directly into values. A downside of using binary files is that the server software must always be running in order to convert the data into a human readable format.
Given the inexperienced nature of the software team, the limited development time, and the unclear specifications, it is not wise to trust safety aspects of the system to software alone. It should also be mentioned that the correct functioning of the system is reliant not only upon the software written during this project, but also the many libraries which are used, and the operating system under which it runs. We found during development that many of the mechanisms for controlling BeagleBone hardware are unreliable and have unresolved issues; see the project wiki pages\cite{mctx3420_wiki} for more information. We attempted to incorporate safety mechanisms into the software wherever possible.
-Sensors and Actuators should define an initialisation and cleanup function. For an actuator (eg: the pressure regulator), the cleanup function must set the actuator to a predefined safe value (in the case of pressure, atmospheric pressure) before it can be deinitialised. In the case of a software error or user defined emergency, the \funct{Fatal} function can be called from any point in the software; this will lead to the cleanup functions of devices being called, which will in turn lead to the pressure being set to a safe value.
+Sensors and Actuators should define an initialisation and cleanup function. For an actuator (e.g.: the pressure regulator), the cleanup function must set the actuator to a predefined safe value (in the case of pressure, atmospheric pressure) before it can be uninitialised. In the case of a software error or user defined emergency, the \funct{Fatal} function can be called from any point in the software; this will lead to the cleanup functions of devices being called, which will in turn lead to the pressure being set to a safe value.
Sensors and Actuators are designed to include an optional \funct{sanity} function which will check a reading or setting is safe respectively. These checks occur whenever a sensor value is read or an actuator is about to be set. In the case of a sensor reading failing the sanity check, \funct{Fatal} is called immediately and the software shuts down the experiment. In the case of an actuator being set to an unsafe value the software will simply refuse to set the value.
\subsubsection{PWM Outputs}
-A single PWM output is used to control a pressure regulator (model: ). The electrical team constructed an RC filter circuit which effectively averages the PWM signal to produce an almost constant analogue output. The period of the PWM is $2\text{kHz}$. This actuator has been calibrated, which allows the user to input the pressure value in kPa rather than having to control the PWM duty cycle corretly.
+A single PWM output is used to control a pressure regulator (model: ). The electrical team constructed an RC filter circuit which effectively averages the PWM signal to produce an almost constant analogue output. The period of the PWM is $2\text{kHz}$. This actuator has been calibrated, which allows the user to input the pressure value in kPa rather than having to control the PWM duty cycle correctly.
\begin{figure}[H]
\item {\bf Unix style authentication}
- Unix like operating systems store a plain text file (/etc/shadow) of usernames and encrypted passwords. To check a password is valid, it is encrypted and then compared to the stored encrypted password. The actual password is never stored anywhere. The /etc/shadow file must be maintained by shell commands run directly from the beaglebone. Alternatively a web based system to upload a similar file may be created.
+ Unix like operating systems store a plain text file (/etc/shadow) of usernames and encrypted passwords. To check a password is valid, it is encrypted and then compared to the stored encrypted password. The actual password is never stored anywhere. The /etc/shadow file must be maintained by shell commands run directly from the BeagleBone. Alternatively a web based system to upload a similar file may be created.
\item {\bf Lightweight Directory Access Protocol (LDAP)}
LDAP is a widely used data base for storing user information. A central server is required to maintain the LDAP database; programs running on the same network can query the server for authentication purposes.
- The UWA user management system (pheme) employs an LDAP server for storing user information and passwords. The software has been designed so that it can interface with an LDAP server configured similarly to the server on UWA's network. Unfortunately we were unable to gain permission to query this server. However an alternative server could be setup to provide this authentication mechanism for our system.
+ The UWA user management system (Pheme) employs an LDAP server for storing user information and passwords. The software has been designed so that it can interface with an LDAP server configured similarly to the server on UWA's network. Unfortunately we were unable to gain permission to query this server. However an alternative server could be setup to provide this authentication mechanism for our system.
\item {\bf MySQL Database}
- MySQL is a popular and free database system that is widely used in web applications. The ability to search for a user in a MySQL database and check their encrypted password was added late in the design as an alternative to LDAP. There are several existing online user management systems which interface with a MySQL database, and so it is feasable to employ one of these to maintain a list of users authorised to access the experiment. UserCake is recommended, as it is both minimalistic and open source, so can be modified to suit future requirements. We have already begun integration of the UserCake system into the project, however a great deal of work is still required.
+ MySQL is a popular and free database system that is widely used in web applications. The ability to search for a user in a MySQL database and check their encrypted password was added late in the design as an alternative to LDAP. There are several existing online user management systems which interface with a MySQL database, and so it is feasible to employ one of these to maintain a list of users authorised to access the experiment. UserCake is recommended, as it is both minimalistic and open source, so can be modified to suit future requirements. We have already begun integration of the UserCake system into the project, however a great deal of work is still required.
MySQL and other databases are vulnerable to many different security issues which we did not have sufficient time to fully explore. Care should be taken to ensure that all these issues are addressed before deploying the system.
\begin{figure}[H]
\centering
- \includegraphics[width=1.1\textwidth]{figures/client_request_flowchart.png}
+ \includegraphics[width=0.8\textwidth]{figures/client_request_flowchart.png}
\caption{High level flow chart of a client request to server response}
\label{client_request_flowchart.png}
\end{figure}
\begin{figure}[H]
\centering
- \includegraphics[width=1.1\textwidth]{figures/fastcgi-flow-chart.png}
+ \includegraphics[width=0.9\textwidth]{figures/fastcgi-flow-chart.png}
\caption{Flow chart of a client request being processed (within the server program). Relevant files are \gitref{server}{fastcgi.c} and \gitref{server}{fastcgi.h}.}
\label{fastcgi-flow-chart.png}
\end{figure}
\url{https://host/api/module?key1=value1&key2=value2...&keyN=valueN} (where \verb/host/ is replaced with the IP address or hostname of the server).
-The API consists of modules that can accept a certain number of arguments (specified as key-value pairs), depending on what that module (Figure \ref{modules}) does. For example, to query the API about basic information (running state, whether the user is logged in etc), the following query is used:
+The API consists of modules accepting arguments (specified as key-value pairs), depending on what that module (Figure \ref{modules}) does. For example, to query the API about basic information (running state, whether the user is logged in etc), the following query is used:
\url{https://host/api/identify}
This request handling code went through a number of iterations before the final solution was reached. Changes were made primarily as the number of modules grew, and as the code was used more.
-One of the greatest changes to request handling was with regards to how parameters were parsed. Given a request of: \url{http://host/api/actuators?name=pregulator\&start_time=0\&end_time=2}, The module handler would receive as the parameters \texttt{name=pregulator\&start_time=0\&end_time=2}. This string had to be split into the key/value pairs to be used, which resulted in the function \funct{FCGI_KeyPair} being made, which was initially sufficient for most cases.
+One of the greatest changes to request handling was with regards to how parameters were parsed. Given a request of: \url{http://host/api/actuators?name=pregulator\&start_time=0\&end_time=2}, The module handler would receive as the parameters \texttt{name=pregulator\&start_time=0\&end_time=2}. This string had to be split into the key/value pairs, so the function \funct{FCGI_KeyPair} being made.
-However, as more module handlers were created, and as the number of parameters required increased, \funct{FCGI_KeyPair} became increasingly cumbersome to use. \funct{FCGI_ParseRequest} was created in response, and internally uses \funct{FCGI_KeyPair}, but abstracts request parsing greatly. In essence, it validates the user input, rejecting anything that doesn't match a specified format. If it passes this test, it automatically populates variables with these values. The \funct{IndentifyHandler} module handler in \gitref{server}{fastcgi.c} is a very good example of how this works.
+With increased usage, this was found to be insufficient. \funct{FCGI_ParseRequest} was created in response, and internally uses \funct{FCGI_KeyPair}, but abstracts request parsing greatly. In essence, it validates the user input, rejecting anything that doesn't match a specified format. If it passes this test, it automatically populates variables with these values. The \funct{IndentifyHandler} module handler in \gitref{server}{fastcgi.c} is a very good example of how this works.
\begin{figure}[H]
\centering
"control_state" : "Running",
"description" : "MCTX3420 Server API (2013)",
"build_date" : "Oct 24 2013 19:41:04",
- "clock_getres" : 0.000000001,
"api_version" : 0,
"logged_in" : true,
"user_name" : "_anonymous_noauth"
To generate the JSON response from the server program, \gitref{server}{fastcgi.c} contains a framework of helper functions. Most of the functions help to ensure that the generated output is in a valid JSON format, although only a subset of the JSON syntax is supported. Supporting the full syntax would overcomplicate writing the framework while being of little benefit. Modules can still respond with whatever format they like, using \funct{FCGI_JSONValue} (aka. \funct{FCGI_PrintRaw}), but lose the guarantee that the output will be in a valid JSON format.
-Additionally, not all responses are in the JSON format. In specific cases, some module handlers will respond in a more suitable format. For example, the image handler will return an image (using \funct{FCGI_WriteBinary}); it would make no sense to return anything else. On the other hand, the sensor and actuator modules will return data as tab-separated values, if the user specifically asks for it (eg: using \url{https://host/api/sensors?id=X&format=tsv})
+Additionally, not all responses are in the JSON format. In specific cases, some module handlers will respond in a more suitable format. For example, the image handler will return an image (using \funct{FCGI_WriteBinary}); it would make no sense to return anything else. On the other hand, the sensor and actuator modules will return data as tab-separated values, if the user specifically asks for it (e.g.: using \url{https://host/api/sensors?id=X&format=tsv})
\subsection{Server API - Cookies}\label{Cookies}
-The system makes use of HTTP cookies to keep track of who is logged in at any point. The cookie is a small token of information that gets sent by the server, which is then stored automatically by the web browser. The cookie then gets sent back automatically on subsequent requests to the server. If the cookie sent back matches what is expected, the user is ‘logged in'. Almost all web sites in existence that has some sort of login use cookies to keep track of this sort of information, so this method is standard practice.
-In the server code, this information is referred to as the ‘control key'. A control key is only provided to a user if they provide valid login credentials, and no one else is logged in at that time.
+The system makes use of HTTP cookies to keep track of who is logged in at any point. The cookie is a small token of information that gets sent by the server, which is then stored automatically by the web browser. The cookie then gets sent back automatically on subsequent requests to the server. If the cookie sent back matches what is expected, the user is `logged in'. Almost all web sites in existence that has some sort of login use cookies to keep track of this sort of information, so this method is standard practice.
+In the server code, this information is referred to as the `control key'. A control key is only provided to a user if they provide valid login credentials, and no one else is logged in at that time.
The control key used is the SHA-1 hash of some randomly generated data, in hexadecimal format. In essence, this is just a string of random numbers and letters that uniquely identifies the current user.
\begin{figure}[H]
\centering
\includegraphics[width=0.8\textwidth]{figures/custom_webserver.png}
- \caption{Block Diagram of a request to a custom webserver}
+ \caption{Block Diagram of a request to a custom web server}
\label{custom_webserver.png}
\end{figure}
-
-Before FastCGI was found, the plan was to build a custom web server (Figure \ref{custom_webserver.png} that used threading. Both the sensor/actuator control and the web interface would reside in the same process. By having both in the same process, continuous control is possible whilst waiting for web requests to be received.
-
-This would have worked, and in fact operates similarly to the final solution, but it was not without drawbacks. By building a custom web server, more effort would have to be spent just to maintain low-level web functionalities, such as responding appropriately to a client request. Perhaps more importantly, features taken for granted from a standard web server would become increasingly difficult to support with a custom web server. For example, services like TLS encryption and PHP support would be near-impossible, or at least very difficult to add. In other words, it was deemed that this solution would be inflexible and not particularly maintainable into the future.
+\r
+Another system considered was to build a custom web server (Figure \ref{custom_webserver.png} that used threading, integrating both the control and web components. This option was primarily discarded because it was inflexible to supporting extended services like PHP and TLS encryption. See \href{https://github.com/szmoore/MCTX3420/issues/6}{Issue 6} on GitHub for more information.\r
\begin{figure}[H]
\centering
Specifically, there was much grief over getting the pins to function correctly, especially for PWM output. Lacking any great documentation, much trial and error was spent determining the best configuration. The BeagleBone Black uses what is termed a ``device tree'' \cite{beaglebone3.8, devicetreetutorial} and ``device tree overlays'' to dynamically determine what each pin does. This is because each pin can have more than one function, so a ``device tree overlay'' determines what it does at any one point. However, this also complicates matters, since what pins do essentially have to be loaded at runtime.
-PWM control in particular took many hours to achieve, which was not helped by a lot of conflicting information available online. As a result, the primary tool used to correctly determine proper PWM control was the use of a cathode ray oscilloscope. Quite briefly, it was found that certain actions had to be performed in a very specific order to make PWM control available. There were also specific limitations, such as pairs of pins being coupled to the same time base (period). The wiki goes into more detail on the issues found.
+PWM control in particular took many hours to achieve, which was not helped by a lot of conflicting information available online. As a result, the primary tool used to correctly determine proper PWM control was the use of a cathode ray oscilloscope. Quite briefly, it was found that certain actions had to be performed in a very specific order to make PWM control available. The wiki goes into more detail on the issues found.
Getting the cameras to work on the BeagleBone was another major issue faced. After much testing, it was simply found that the cameras could only work on the latest version of the operating system. On anything else, only low resolution captures of around 352x288 pixels could be achieved.
-Finally, it should be noted that USB hotplugging does not work on the BeagleBone. This means that the cameras have to be plugged in before booting the BeagleBone. Upgrading to a newer kernel (when it exists) should solve this issue.
+Finally, it should be noted that USB hot-plugging does not work on the BeagleBone. This means that the cameras have to be plugged in before booting the BeagleBone. Upgrading to a newer kernel (when it exists) should solve this issue.
\subsection{Required software}
These packages should be installed with the command \texttt{apt-get install}.
\subsection{Required configurations}
-Many components need to be configured correctly for the server to work. In particular, these configurations relate to the web server, nginx, as well as logging software used, rsyslog. These configurations are automatically installed by a specific script on the git repository.
-
-There is a folder, labelled server-configs. Executing \gitref{server-configs}{install.sh} as root should install all the required configuration files to run the server correctly.
+Many components need to be configured correctly for the server to work. In particular, these configurations relate to the web server, nginx, as well as logging software used, rsyslog. Executing \gitref{server-configs}{install.sh} as root should install all the required configuration files to run the server correctly.
% END Jeremy's section
\subsection{Results}
-Figure \ref{image_in_api.png} shows an image obtained from one of two dilatometers used in the system setup with collaboration between all teams. The image is of a white lego tile attached to the can. This image was successfully streamed using the server software, and results of the dilatometer readings were monitored using the same software. Unfortunately we were unable to maintain a constant value for a stationary can, indicating that the algorithm needs further development. Due to a leak in the can seal we were unable to pressurize the can sufficiently to see a noticable change in the edge position.
+Figure \ref{image_in_api.png} shows an image obtained from one of two dilatometers used in the system setup with collaboration between all teams. The image is of a white Lego tile attached to the can. This image was successfully streamed using the server software, and results of the dilatometer readings were monitored using the same software. Unfortunately we were unable to maintain a constant value for a stationary can, indicating that the algorithm needs further development. Due to a leak in the can seal we were unable to pressurize the can sufficiently to see a noticeable change in the edge position.
\begin{figure}[H]
\centering
\includegraphics[width=0.6\textwidth]{figures/image_in_api.png}
- \caption{Microscope image of actual lego tile attached to can in experimental setup}
+ \caption{Microscope image of actual Lego tile attached to can in experimental setup}
\label{image_in_api.png}
\end{figure}
% BEGIN James' section
\subsection{Design Considerations}
-There are many considerations that are required to be taken into account for the successful creation of a Graphical User Interface (GUI) that allows Human Computer Interaction. A poorly design GUI can make a system difficult and frustrating to use. A GUI made with no considerations to the underlying software can make a system inoperable or block key features. Without a well designed GUI the Human Computer Interaction becomes difficult and discourages any interaction with the system at all.
+There are many considerations that are required to be taken into account for the successful creation of a Graphical User Interface (GUI) that allows Human Computer Interaction. A poorly designed GUI can make a system difficult and frustrating to use. A GUI made with no considerations to the underlying software can make a system inoperable or block key features. Without a well designed GUI the Human Computer Interaction becomes difficult and discourages any interaction with the system at all.
One of the key considerations made during the design of the GUI was the functionality it required. Originally this was limited to just allowing for simple control of the system including a start and stop and a display of system pressures however as the project progressed this was expanded to include a user login, limited admin functionality, graphing, image streaming and live server logs. The addition of these features came as a result of changing requirements from the initial brief as well as logical progression of the GUI's capabilities. This gradual progression represents a continual improvement in Human Computer interaction for the system.
Due to the limits of the Beagle Bone such as available memory and processing power it was important that the code, images and all libraries used were both small in size and efficient. This meant that careful consideration had to be made every time a library was considered for use. It also meant that where possible processing should be offloaded onto the client hardware rather than running on the server which already runs the server side code. This meant large libraries were ruled out and actions such as graphing were performed by the GUI on the client machine.
- The final consideration is extensibility. An extensible software base code allows easy addition of new features. A good extensible interface makes it a simple case of simply dropping the extra code in in order to add extra features whereas a GUI that doesn't take this into account can require deleting and recoding of large chunks of the previous code. This means that the interface code must be structured in a coherent way and all conform to a ``standard'' across the GUI. Code must be laid out in the same way from page to page and where possible sections of code facilitating specific goals should be removed from the main page code. The latter was achieved through the use of the \verb/.load()/ JavaScript function allowing whole widgets to be removed and placed in their own seperate files. This feature alone lets the developer add new widgets simply by creating a widget file conforming to the GUI's standard and then \verb/.load()/ it into the actual page.
+ The final consideration is extensibility. An extensible software base code allows easy addition of new features. A good extensible interface makes it a simple case of simply dropping the extra code in in order to add extra features whereas a GUI that doesn't take this into account can require deleting and recoding of large chunks of the previous code. This means that the interface code must be structured in a coherent way and all conform to a ``standard'' across the GUI. Code must be laid out in the same way from page to page and where possible sections of code facilitating specific goals should be removed from the main page code. The latter was achieved through the use of the \verb/.load()/ JavaScript function allowing whole widgets to be removed and placed in their own separate files. This feature alone lets the developer add new widgets simply by creating a widget file conforming to the GUI's standard and then \verb/.load()/ it into the actual page.
\subsection{Libraries used in GUI construction}
Flot\cite{flot} is a Javascript library designed for plotting and built for jQuery. This a lightweight easy to use library that allows easy production of attractive graphs. It also includes advanced support for interactive features and can support for $\text{IE} < 9$ . The Flot library provided an easy but powerful way to graph the data being sent by the server.
-\subsection{Libraries trialed but not used in GUI construction}
+\subsection{Libraries trialled but not used in GUI construction}
These are libraries that were looked at and considered for use in the GUI software but were decided to not be used in the final product.
\begin{figure}[H]
\centering
\includegraphics[width=0.8\textwidth]{figures/draftGUI.png}
- \caption{Draft GUI designed in Microsoft Powerpoint}
+ \caption{Draft GUI designed in Microsoft PowerPoint}
\label{draftGUI.png}
\end{figure}
\end{figure}
-This gui was running over a free domain name which allowed us to play with control and command.
+This GUI was running over a free domain name which allowed us to play with control and command.
\subsection{Iterations}
-After the basic testing of the initial GUIs we started playing with gui design ideas which would be aesthetic, easy to use and reflect on UWA in a positive way. To do this we looked into how professional websites were made by opening their source code and investigating techniques into layout, structure and style. Then we went away and completed some gui design trees, where there would be a clear flow between pages.
+After the basic testing of the initial GUIs we started playing with GUI design ideas which would be aesthetic, easy to use and reflect on UWA in a positive way. To do this we looked into how professional websites were made by opening their source code and investigating techniques into layout, structure and style. Then we went away and completed some GUI design trees, where there would be a clear flow between pages.
\subsection{Parallel GUI Design}
-During the GUI development phase, several GUIs were created. Some used graphical development software, while others used hard codded HTML, JavaScript, and CSS. Due to no organization within the group and a lack in communication a “final gui” was made by several of the team members. Some of theses are shown below.
+During the GUI development phase, several GUIs were created. Some used graphical development software, while others used hard codded HTML, JavaScript, and CSS. Due to no organization within the group and a lack in communication a ``final GUI'' was made by several of the team members. Some of theses are shown below.
\subsection{GUI Aesthetics}
-Once we had decided on our core GUI design, we decided that, although not yet complete we would get Adrain Keatings opinion on the GUI design. While the gui design was simple and functional Dr. Keating pointed out the design was bland. He encouraged us to release our artistic flair onto our GUI and make it more graphical and easy to use. Taking this into account we Began work on another final GUI designing almost from scratch. We kept our GUI design flow, and worked largely on the look and feel of the GUI rather the functionality the gui needed.
+Once we had decided on our core GUI design, we decided that, although not yet complete we would get Adrian Keating's opinion on the GUI design. While the GUI design was simple and functional Dr. Keating pointed out the design was bland. He encouraged us to release our artistic flair onto our GUI and make it more graphical and easy to use. Taking this into account we began work on another final GUI designing almost from scratch. We kept our GUI design flow, and worked largely on the look and feel of the GUI rather the functionality the GUI needed.
\subsection{HTML Structure}
-The way our GUI works, in a nutshell, is that we use Basic HTML code to lay out what the page needs, then we have CSS(Styles) on top which lays out and formats the basic HTML code. We the put JavaScript files into the HTML code so that graphs and images and be streamed. In out GUI we have chosen to use JQuery to ask the server for information from the client and jFlot for javascripts graphing functionality.
+The way our GUI works, in a nutshell, is that we use Basic HTML code to lay out what the page needs, then we have CSS(Styles) on top which lays out and formats the basic HTML code. We the put JavaScript files into the HTML code so that graphs and images and be streamed. In our GUI we have chosen to use JQuery to ask the server for information from the client and flot for graphing functionality.
\subsection{Graphical Development VS Hard Coding}
-From the Multiple GUI we had accidently created during the GUI design phase we noticed a large Varity in the styles of GUIs that came out (Which shouldn’t of happened) GUIs were created using HTML CSS and JavaScript being hard codded, from development software like Dreamweaver, and various java based development platforms.
+From the Multiple GUI we had accidentally created during the GUI design phase we noticed a large variety in the styles of GUIs that came out (Which shouldn't have happened) GUIs were created using HTML CSS and JavaScript being hard coded, from development software like Dreamweaver, and various Java based development platforms.
\subsection{Final Design}
\begin{figure}[H]
\centering
\includegraphics[width=0.8\textwidth]{figures/gui_pintest.png}
- \caption{The BBB Pin test page is for the software team only so that we can test and debug the experiment we errors are found in the gui or software. }
+ \caption{The BBB Pin test page is for the software team only so that we can test and debug the experiment we errors are found in the GUI or software. }
\end{figure}
\begin{figure}[H]
\section{System Overview}
-To aid understanding of the context of the software project, a brief overview of the system as a whole is presented below. Essentially, the MCTX3420 project apparatus is designed to test the behaviour of a pressure vessel as air pressure inside it is gradually increased. A very basic system diagram showing the main components is shown in Figure \ref{system_overview.png}, with control components in \textcolor{red}{ red}, electronics in \textcolor{green}{ green}, sensors in \textcolor{Purple}{ purple}, pneumatics in \textcolor{blue}{ blue}, and experimental targets in \textcolor{Orange}{ orange}.
+To aid understanding of the context of the software project, a brief overview of the system as a whole is presented below. Essentially, the MCTX3420 project apparatus is designed to test the behaviour of a pressure vessel as air pressure inside it is gradually increased. A very basic system diagram showing the main components is shown in Figure \ref{system_overview.png}, with control components in \textcolor{red}{ red}, electronics in \textcolor{green}{ green}, sensors in \textcolor{Purple}{ purple}, pneumatics in \textcolor{blue}{ blue}, and experimental targets in \textcolor{Orange}{ orange}.
\begin{figure}[H]
\centering
\end{itemize}
-The system software essentially is defined by the “control” component: allowing a user to control the experiment hardware. To do this, the software must successfully interface with all of the system areas above so that the desired experiment can be run.
+The system software essentially is defined by the ``control'' component: allowing a user to control the experiment hardware. To do this, the software must successfully interface with all of the system areas above so that the desired experiment can be run.
\section{Development Process}
\begin{enumerate}
\item Create an individual ``fork'' of the software, separate from the main branch.
\item Modify this fork on a local machine with proposed changes or additions. This fork is also updated regularly with any changes that were made in the main branch.
- \item When work is complete, create a ``pull request'' to merge local changes back into the main codebase.
+ \item When work is complete, create a ``pull request'' to merge local changes back into the main code base.
\item The pull request can be reviewed by other team members; if everything fits, the request is accepted and the local changes become part of the main code.
\end{enumerate}
In this way, GitHub automates the more tedious aspects of code management.
\subsection{Testing}
-Once the software section is relatively complete, it can be tested with the larger codebase. This was generally done through writing specific test functions. Because the operating system on the BeagleBone (GNU/Linux) is widely available for commercial PCs and laptops, software development and testing could occur without needing to wait for a BeagleBone to become available. Code was also tested on the BeagleBone itself where possible to ensure correct operation. One example is for the sensors software - initially, functions were written that simulated sensors, so it could be tested if data was read correctly. These functions were rewritten for use with actual hardware as the specifics became known later in the project.
+Once the software section is relatively complete, it can be tested with the larger code base. This was generally done through writing specific test functions. Because the operating system on the BeagleBone (GNU/Linux) is widely available for commercial PCs and laptops, software development and testing could occur without needing to wait for a BeagleBone to become available. Code was also tested on the BeagleBone itself where possible to ensure correct operation. One example is for the sensors software - initially, functions were written that simulated sensors, so it could be tested if data was read correctly. These functions were rewritten for use with actual hardware as the specifics became known later in the project.
\subsection{Collaboration}
After the testing process is satisfied, the final code can be committed to the system. This requires input from the other project teams. If there is any feedback or the requirements change in the future, the code can be edited through the above process.
\subsection{Communication} \label{Communication}
The primary time for collaboration was during the team's weekly meetings. Meetings occurred at 2pm-4pm on the Monday of every week, and were generally attended by all group members. While most work was expected to be done outside this time, the meetings were valuable for planning and scheduling purposes, for tackling problems and making design decisions as a group. Team members were able to work together in the meetings to complete certain tasks much more effectively. Importantly, at the end of each meeting, a report of the work done during the prior week and a list of tasks to do the following week was produced, giving the project a continuous, clear direction.
-GitHub was used as the group's repository for software work. The usefulness of GitHub was explained previously in the “General Development Process” section, but essentially, it is a very effective tool for managing and synchronising a large, multi-person software project. GitHub also features a notifications and issue-tracking system, which was useful for keeping track of tasks and immediately notifying team members of any changes.
+GitHub was used as the group's repository for software work. The usefulness of GitHub was explained previously in the ``General Development Process'' section, but essentially, it is a very effective tool for managing and synchronising a large, multi-person software project. GitHub also features a notifications and issue-tracking system, which was useful for keeping track of tasks and immediately notifying team members of any changes.
Outside of meetings, email was the main form of communication. Email threads exist for all of the project's main areas, discussing any ideas, changes or explanations. Email was also used for announcements and to organise additional meetings. For less formal communication, the software group created their own IRC channel. This was essentially a chat channel that could be used to discuss any aspect of the project and for communication about current work.
\subsection{Group Participation}
-The nature of software development means that it tends to be very specialised --- extensive knowledge of coding is required to be effective, which is difficult to learn in a short timeframe. The members of the software team all had varying levels of experience, and therefore could not contribute equally to all areas of the project. Some team members had done very little coding before (outside of introductory units at university) which made it difficult for them to contribute in some areas, while others had the extensive knowledge required.
+The nature of software development means that it tends to be very specialised --- extensive knowledge of coding is required to be effective, which is difficult to learn in a short time frame. The members of the software team all had varying levels of experience, and therefore could not contribute equally to all areas of the project. Some team members had done very little coding before (outside of introductory units at university) which made it difficult for them to contribute in some areas, while others had the extensive knowledge required.
However, different team members had skills in other areas besides coding, and these skills were allocated to ensure that all members could contribute effectively. For instance, as some people worked on the server code, others worked on the visual GUI design; it made sense for the people who were most efficient with coding to work on those elements while others performed different tasks. Even though the software project was principally coding, there were many supplementary development tasks --- writing documentation, hardware testing, et cetera --- that were involved. Some areas of the software, such as the BeagleBone interfacing, were new to all team members and were worked on by everyone.
\subsection{Individual Contributions}
-Software project tasks were divided up between team members, and in this report, each team member has generally been the writer of the sections they actually worked upon. Throughout the project, team members had clear areas of responsibility, and their work can also be followed through the GitHub repository (which allows tracking of individual contributions to the codebase). Below is a rough summary of individual areas of interest:
+Software project tasks were divided up between team members, and in this report, each team member has generally been the writer of the sections they actually worked upon. Throughout the project, team members had clear areas of responsibility, and their work can also be followed through the GitHub repository (which allows tracking of individual contributions to the code base). Below is a rough summary of individual areas of interest:
\begin{tabular}{l|l}
{\bf Team Member} & {\bf Development} \\
It should also be noted that team members often helped each other with designing, problem solving and testing, so members did end up contributing in some way to most areas of the software.
-Server coding tasks included the threading system, data handling, sensors/actuators control, authentication, server/client communication, http/s use, FastCGI, AJAX and the server API, which were split mainly by Sam and Jeremy (with significant overlap). BeagleBone interfacing included hardware access, pin control, networking and testing, and involved most members of the team. Sam, Jeremy and Justin focused on pin control, Jeremy and Callum investigated webcam use, and Rowan performed additional testing. GUI design involved the visual design elements, HTML/CSS webpage coding and Javascript functionality. James was primarily in charge of the GUI design, functionality and implementation, with assistance and alternate designs provided by Jeremy. Other team members were responsible for individual GUI sections, including Sam (graphs), Justin (help and data) and Rowan (widgets). Other tasks included image processing with OpenCV (Callum) and project documentation and safety (Justin).
+Server coding tasks included the threading system, data handling, sensors/actuators control, authentication, server/client communication, HTTP(S) use, FastCGI, AJAX and the server API, which were split mainly by Sam and Jeremy (with significant overlap). BeagleBone interfacing included hardware access, pin control, networking and testing, and involved most members of the team. Sam, Jeremy and Justin focused on pin control, Jeremy and Callum investigated webcam use, and Rowan performed additional testing. GUI design involved the visual design elements, HTML/CSS webpage coding and Javascript functionality. James was primarily in charge of the GUI design, functionality and implementation, with assistance and alternate designs provided by Jeremy. Other team members were responsible for individual GUI sections, including Sam (graphs), Justin (help and data) and Rowan (widgets). Other tasks included image processing with OpenCV (Callum) and project documentation and safety (Justin).
\subsection{Cost Estimation}
git.ucc.asn.au / matches / MCTX3420.git / commitdiff
UCC git Repository :: git.ucc.asn.au