First prototype

So we decided that 3D printing service will take quite a little bit of time and we are not yet ready to finalize the design for it, among other things (the cost is a headache too!). Since the first presentation is just around the corner, we gonna go with a quicker solution : a prototype made wholly out of wood. We have been going around the hardware shops nearby and finally able to get some good looking woods for our project with cheap cost.

Due to the lock requires drop bolt hole component to be mounted, a stand for it is needed. The lock senses the component in order to drop the bolt. Since we need to build that stand, we thought it is a good idea to have the electronic lock able to swing just a little bit. At the end, we got ourselves a smaller scale door, which looks 'okay' enough for the presentation. We probably need more than this to impress the moderator, though.

You can get the Sketchup file here : First Prototype

Time for part timer carpenters to go to work.

A sample RFID based electronic door lock

During the last meeting, Mr Cheong showed us the sample of the electronic door lock from the market. We were informed with some useful information on the regulation of the general door lock (before they can be marketed) here in Malaysia. The sample is a RFID based electronic door lock that also comes with the manual keyhole for the backup. It is actually a better idea to have the similar basic design for our project, albeit it comes with a higher cost.

The sample looks good, and I hope we can build something similar for our demo as well.

2nd try on demo box

So, we had ourselves a barrier : the 3D printing service can only print at most 20cm X 20cm in size. Our electronic lock itself is already about 19cm, which tells us that we can't print the whole previous design in one shot. What we can do is to print them part by part and combine them together with screws or glue.

So, I gave another shot on how it will sorta look like if we were to go that way. You can get the Sketchup file here : Second Design

Building the prototype for demo

For obvious reason, we can't put our system on a real door during demonstration. So, we need a smaller, nice looking way of showing that our system can work.

The Kevo's demonstration uses a small box made of wood, which is actually looks nice and serve the purpose (shows how the system works) nicely. You can watch it from the video:

However, due to lack of time and resources, we have opted to build our prototype for demo by using 3D printing service. With some serious lack of creativity, I tried designing using the same idea, just to see how we can arrange our system components inside the box. This is, by no mean, the final design.

As you can see, there are pretty big empty spaces inside the box which can fitted with other components if needed (a battery, perhaps?). After asking around on 3D printing service available, I found out that the maximum of the printable size is 20cm x 20cm x 20cm volume. That is one big concern, our lock itself is already 199mm (19.9cm) in length. Trouble!

Well, not entirely true. We have the option to print part by part and gluing them together, but I'm not sure how strong can it be. The material provided are mostly ABS or PLA. ABS is stronger, the kind of material that the car's bumper are made of, but the maximum printable size is about 10cm x 10cm x 10cm due to the warping problem. We still need to design correctly (if you notice, I haven't plug in the Bluetooth dongle into the Rpi yet) and we still need to seek answers!

Here's a little conversation of me and one of the 3D printing service providers:


Hi

I'm gathering info about 3D printing service, which I need for my fyp. I was given your contact...I hope you don't mind, I'd like to ask a few questions:

1. Can I know the price rate for the service? How it depends on the size, weight of material used, complexity...any other applicable etc

2. What is the maximum printable size?

3. Which materials do you guys provide?

4. How to make order? Expected delivery period?

Thanks

The reply:

Hello

1. For 3D printing targeted towards the consumer market, the prices can range from RM5 all the way to RM1,000. For our company, Makerzone, we charge based on weight and time taken (Rm30 per hour) to print an object. The more complex the object is, the longer time it takes to print it so higher cost too. However, we do have substantial discount for students.

2. For our printers currently, our maximum printable size is 20cm x 20cm x 20cm volume. ABS is limited to 10cm x 10cm x 10cm to prevent warping.

3. We provide both ABS and PLA filaments. Honestly after selling products the past few months, the type of filaments that we use do not matter much to our consumers. We also provide post-processing for customers if they want such as polishing the printed object which will make it looks smooth and shiny, painting and chroming.

4. Customers can make orders through our online platform where we host our marketplace of products. We own three websites currently but they are all still under development and not fully functional yet. Please feel free to check them out too.

www.makerzone.net    www.makerzone.com.my    www.makerzone.sto.my 

Please do like our page below too! 
https://www.facebook.com/makerzone

It is good that you have a sketch of your design, it makes it so much easier for us to provide a quotation for you. Therefore, you could drop an email to mak@makerzone.net together with your sketchup design for him to provide validation and quotation. Expected delivery period is within 5 working days.

Python - GUI and MySQL

Since we are going to deploy the system to consumer level, the interface of our application should be intuitive, more or less, looking the same as with other typical desktop applications. And to some extent, it should resemble our Android App in the design.

We have decided to use MySQL for the database of our application. For web application, I am most certain that PHP would be the best to use. However, we would want a standalone desktop application for our system. The desktop application should be able to execute these 3 main general functions:

   1. Communicate with our MySQL database (of course!)
   2. Communicate with Rpi via bluetooth
   3. Communicate with Android App via bluetooth.

Since we're using Python on Rpi itself, perhaps it's good for me to explore on how we can use Python in this area as well, eliminating the needs for PHP. We basically know that Python bluetooth communication with Rpi and Android App is implementable. So, what I need to know for now are:

How Python can be used to write a desktop application?
What GUI tools do I need?
Can it be installed in main PC platforms (Windows, Linux, Mac)?
How Python can be used along with MySQL database?

A quick research led me to PyQt, a Python way of using cross-platform GUI toolkit, QT. From the Wiki page of PyQt, there are other GUI toolkits available for Python as well. However, we'll stick to PyQt for now due to the fact that it is cross-platform. I have implemented Qt before in my Object Oriented programming course - I wrote a Hang Man's words game and used Qt for the drawing.

Below is the introductory video on PyQt and here is a good tutorial site for PyQt : Link.

I also found out that, similar to PHP, Python can also be used with MySQL with ease. These two links below shows how it is done. I'll try these out later when I want to get started with our desktop application.

Link 1 : Connecting to MySQL with Python and PHP
Link 2 : MySQL Python tutorial

New GUI Design

I just saw this App and I thought it looks simple, clean and nice. I am a big fan of simplicity. So, I decided to draw using the similar theme for our App. I'll code this later.

Expense Manager 

GUI Design

I have not been focusing on GUI design yet as I prefer to make sure some basic functions for the App are working first. The idea is to write these different functions separately into multiple temporary Apps for testing/debugging and then I'll combine these into our final App. Even so, I did play around with the Android GUI just to get the feel of them.

The Eclipse provides basic drag and drop with their graphical tools but sometimes they could go wrong. The attributes of each view that we use can be incorrectly set up by the tools and although it looks nice on Eclipse, it isn't so on your phone. Also, we need to cater to different screen sizes, ensuring that the looks do not go wrong.

So, the best way is to study on these different layout properties first i.e. Grid Layout, Linear Layout, Relative Layout and also Android views. There is also a guidelines for the GUI design at Android Developer site. I have read a good book on this, I'll get back to attaching it here later.

So far, these are a couple of GUI designs that I played with

I think the best looking one at this moment is the one below. But I still can think of some changes that I can make on the look (Especially our faces right there, haha). If you have any suggestions, comments or samples, go ahead and let me know.

On Phone

On Galaxy Tab

Python server is now working

Earlier, we have a problem in sending the data from the Android App to the Python server on Rpi. I wrote:

"On Rpi, the App shown that connection has been made with the server and data has been successfully sent, but none of those are indicated on the server that I ran"

Well, I was half correct and half wrong.

Based on this thread, the problem lies in the default configuration of Bluez where pnat plugin (a plugin file written in c for Nokia's Maemo platform) is enabled. The plugin effectively breaks any application that tries to run Rfcomm server. Running the App through Eclipse shows "connection reset by peer" error even though initially connection was made. So, the connection was initially made, but it is then terminated by the plugin right at the point where data is to be send.

To fix this, just disable pnat plugin.
1. Navigate to  "/etc/bluetooth/main.conf"
2. Edit the file with root "sudo nano main.conf"
3. Append the following "DisablePlugins = pnat" in the main.conf file.
4. Save and Exit - Press 'CTRL-X' and 'Enter'
5. Restart bluetooth by issuing "sudo invoke-rc.d bluetooth restart"