17. Applications and Implications, Project Development¶

Weekly Digest (Thu. May 23 to Wed. May 30)¶

Date	Time	Place	Activities
Thu. May 23	14:00-17:00	Office (NID)	Prototyping of a Clutch Bag
Sat. May 25	10:00-20:30	FabLab Kannai	Local Session for Week17
Mon. May 27	10:00-17:00 19:00-25:00	Office (NID) Home	Programming, App Review, Packaging for Final Project
Tue. May 28	10:00-17:00 19:00-21:00	Office (NID) Home	App Review, Packaging for Final Project
Wed. May 29	7:00-9:00 10:00-17:00	Home Office (NID)	Documentation for Week 17 App Redesign

Assignment¶

With the date of our Final Project presentation getting closer, there is no group assignment. Individual assignment has something to do with our own Final Project.

 - Propose a final project masterpiece that integrates the range of units covered, answering:                        
     What will it do?
     Who's done what beforehand?
     What will you design?
     What materials and components will be used?
     Where will come from?
     How much will they cost?
     What parts and systems will be made?
     What processes will be used?
     What questions need to be answered?
     How will it be evaluated?

Rationale of the Project¶

I understood that most of the elements presented above by the instructors have already been mentioned in the Final Project page, and the instructors also said that they should be mentioned there. Although I understand what we are supposed to do was not to enrich the Weekly Assignment page for Week17, but the Final Project page, I am going to take time to write up how I am going to respond to these requirements as part of warm-up to update the Final Project page.

“What will it do?”¶

Scare the theif who tries to steal your valuables.
Alert you that you are moving away from your valuables.
Familizarize you to digital fabrication by making the replica locally.

“Who’s done what beforehand?”¶

Apple’s Air Tag is already available in the market. While the Air Tag is available only for iPhone, there is a similar device for Android mobiles. However, this device is designed to locate the tagged item on the map and it doesn’t protect you from having your valuables stolen or just left behind.

“What will you design?” “What parts and systems will be made?”¶

Alarm Device that could be tagged to the passport. It should look like a small box in which the customized PCB and all the components are packaged. The cover and the main body of the box are 3D-printed. The attached image is the rendering of the design by Fusion360. Currently the first model of the box mount is made by FDM printer. But the final model for Final Project presentation would be made by SLA printer.

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Clutch Bag in which we could keep the passport and the alarm device together. It’s made of leather cut out by the lasercutter and then hand-sewn.

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Android Mobile App that could be paired to the Alarm Device. It reads the RSSI and if the passport (and the Alarm Device) moves away from the mobile phone, the app plays the siren while it sends a message to the Alarm Device to turn on the buzzer. The attached images are the first model of the UI, and it will be upgraded by the Final Project presentation.

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Instruction Manual for Local Production and Assembly that could help the users to make the whole package locally with the facility and advice by the FabLab near them.

Materials and Components¶

The following is the latest BOM. You can read the whole list by reducing the size from 100 percent to 50 percent on the Google Spreadsheet. It should be noted that it includes two expensive items: UV resin for SLA printer and craft leather for making a leather bag for passport and the alarm device. If we do without them and use the FDM printer instead of SLA printer for making the device box, the cost could be reduced to less than JPY 3,500.

What processes will be used?¶

I understand that this question have something to do with our weekly activities and we need to make clear which module has contributed to our Final Project. Although I didn’t rewrite each weekly assignment page in the context of my Final Project, I would like to make it clear that the following weekly activities have been contributing to my project design.

Week	Module	How It Contributed to My Final Project
Week 1	Principles and Practices, Project Management	Website development
Week 2	Computer-Aided Design	2D design
Week 3	Computer-Controlled Cutting	Lasercutting
Week 4	Celectronics Production	PCB milling and soldering
Week 5	3D Scanning and Printing	3D design and printing
Week 6	Embedded Programming	Arduino and MicroPython IDE
Week 8	Electronics Design	EDA design
Week 9	Output Devices	Buzzer and Speaker, PWM control
Week 12	Molding and Casting	3D design of the Alarm Device box cover
Week 13	Networking and Communications	Bluetooth Low Energy (MIT App Inventor)
Week 14	Interface and Application Programming	Mobile Appr IDE (MIT App Inventor)

What question need to be answered?¶

Perhaps I may not be understanding this question as the Fab Academy organizer expected. I understand that it’s about the problems and challenges I have faced during the project development process and those which are left unsolved. I have been trying to address all of them toward the end of the Fab Academy. The progress updates are added periodically to the paragraphs below. They could be monitored in the Project Monitoring Sheet.

a. Alarm Device¶

Board Selection: I started this journey hoping to use Seeed Xiao ESP32C3 as my development board. But I faced lots of issues in coding with Arduino IDE and at the very last moment I switched to Raspberry Pi PicoW. With regards to Arduino IDE, I still do not understand why I faced so many compilation and uploading errors. That should be addressed.
Buzzer: In order to scare those who try to steal our valuables, buzzer volume should be as loud as possible. Due to time constraints, I compromized by applying PWM control. But I feel that I should try more options to make the buzzer sound very alarming so that everyone around it could pay attention to it.
Power Supply: I have confirmed that the circuit for the buzzer beat was working with the 3.3V power supply when it’s connected to the USB power supply cable. But as of the morning of Wednesday, May 29, I have not been successful to supply power to the buzzer. Although I tested the power supply circuit with four 3V coin batteries (12V altogether), with the step-down regulator in between, before I proceeded to the PCB design, I haven’t got the buzzer beat with my board. (Update (June 23, 2024): This issue was already addressed.)

b. Mobile App¶

Functional Problems: I designed the mobile app in Week14 and wrote that I faced a few problems (See Individual Assignment for Week14.) Most of them have not been rectified yet as of the morning of Wednesday, May 29. (Update (June 23, 2024): Most of the problems I mentioned here were already addressed or evaded. I added a video on the Week14 page that would show the mobile app and the Alarm Device were interfaced.)
RSSI Read: I took the orthodox approach by looking at the mobile phone as a BLE central device. At first, I considered writing a program that the BLE peripheral device, the Alarm Device, would read the RSSI and start/stop playing the buzzer on the peripheral device side. But at the last moment I have found that it was the central device that would usually read the RSSI. That forced me to reconsider the user interface. After a few iterations, I set the threshold as -70dBM read so that the peripheral device moves away just once approximately 10 meter from the central device.
Mobile Phone as BLE Peripheral: I learned that there would be an alternative approach: What if I look at the mobile phone as a BLE peripheral device? However, expecting that it would take much longer time to remake the mobile app and write a new code to have the Alarm Device read the RSSI and find the trigger to play the buzzer. This option needs to be explored in the long run. But for the Final Project presentation in the very short-run, I thought that I should stick to the initial approach of mobile phone as a central device.

c. Program Code¶

Alarm Device: I have confirmed that the following codes are working with my board if I tested them one by one: (i) Playing the buzzer; (ii) BLE peripheral advertizing. But I still need to test the program for receiving messages from the BLE central device. And also I need to integrate them and see if they would work. (update (June 23, 2024): They are now integrated and the evidence video is uploaded in the Week14 Individual Assignment page as well as the Final Project page. )
Mobile App: I have confirmed that the following code blocks are working with the peripheral device: (i) BLE connection, (ii) Read RSSI, and (iii) Siren on the BLE central if the RSSI is weak. However, the following code blocks still need to be added: Send messages to turn on/off the buzzer on the BLE peripheral device. (Update (June 23, 2024): These issues were already addressed as described above.)

d. Users Manual¶

There should be two user manuals for: (i) Operations, and (ii) Local Production and Assembly. These should be developed after the Final Project presentation. (Update (June 23, 2024): Operations Manual is already developed and uploaded on the Final Project page.)

How will it be evaluated?¶

At the initial stage of the project, I consulted with the officials of the Japan International Cooperation Agency (JICA) and agreed that I would make the presentation on my prototype. They apply for official passports for their officials sent out to developing countries every year to the Government of Japan. The prevention of official passports lost or stolen has been a critical issue for JICA for so many years and they are searching for a solution to reduce such cases to zero. Hopefully my project could be one of the candidates.

After the functional evaluation at the Head Office level, it will be brought to another evaluation, about the adoptability at the country office level. Since each country office has to approach the FabLab in the country and the staff have to undertake the local production and assembly, we have to see if these technological elements, such as 3D-printing, lasercutting, PCB milling and soldering, debugging etc., could remain in the acceptable level for those staff who do not have much knowledge about digital fabrication.

Last update: June 23, 2024