Week 13. Applications and Implications

13. Applications and Implications


Propose a final project that integrates the range of units covered. See Final Project Requirements for a complete list of requirements you must fulfil. assignment Propose a final project masterpiece that integrates the range of units covered,
- 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?

  Your project should incorporate 2D and 3D design,  
     additive and subtractive fabrication processes,  
     electronics design and production,  
     microcontroller interfacing and programming,  
     system integration and packaging  
  Where possible, you should make rather than buy
     the parts of your project  

Have you answered these questions?

what will it do?

We envision a smart wearable optimised for delivering haptic in- and output for VI. By starting with presenting notifications via vibrations and input via buttons and tap patterns, we believe we can create a small, affordable and flexible wearable that is easy to use by VI.


  • Recognise tap gestures via accelerometer
  • Vibrations as output
  • Has at least one button for input
  • Bluetooth connected to phone
  • Can work standalone as watch (tap pattern for getting time in vibrations)
  • LED indicators (for debugging)
  • USB-port for power and programming
  • Uses (rechargeable) battery
  • Long battery life: last at least a day preferable a week or longer

What parts and systems will be made?

  • Micocontroller with vibration motor, Bluetooth module, and accelerometer.
  • Casing for the microcontroller
  • Smartphone app for Bleutooth communication

What materials and components will be required?


  • Microcontroller -> Henk advices to use the Atmega 328p instead of the ATTiny becasue it has more memory., Waag,
  • Accelerometer -> MPU6050 (used in week 12), supply myself
  • Vibration motor -> used in week 11, supply myself, estimated cost about 50 cents
  • button -> fabacademy
  • Bleutooth chip with antenna (BLE 4.0) - NR4871, supply fabacdemy
  • Battery -> myself, salvaged from toy, about 1 euro estimated cost
  • various components for charging battery, supplied by Henk (fabacademy), cost about 3 euros
  • various components for power to module (3V or 5V?) from USB, about 1 euro
  • various LEDs, resistors, capacitors, ect. each component is a few cents each, so total will be about 5 euros max
  • PCB
  • casing (plastic/wood/fabric), one set is about 20 euros, wood will be 5 euros or even only scrap wood, I only need small pieces. fillament for the 3D printer will be a few meters, so max 5 euros

What processes will be used?

Who has done what beforehand?

Jin Hyeok Cardiac arrest smart band Jin Hyeok has created a smartband that can detect a cardiac arrest. Jin uses an external accelerometer board. From Jin I learn that it is possible to create a 3D printed casing that is solid enough to use for a smart band. Further although his band is quite large, I find the design elegant. My band will have 3 times the features, and I want it to be at least twice as small.

Beautifull led arm band of David David has a beautifull designed smart band, unfortunately it only can show lights, does not have any communication or GPS, or accelerometer.

WALLTECH open source smart watch
David linked from his site to an Open Source Android watch WALLTECH smartwatch. A beatifull complete design, with screen and accelerometer and bluetooth. It uses the Atmel32 and a Nordic chip for Bluetooth. Both chips are very difficult to solder by hand, and will need mee first practicing the reflow oven, if I want to use this design. It does inspire me though that is possible to make a full smart watch by one person.

Fab Watch Mohammed created a smartwatch that uses Bluetooth and has a screen. Very impressive result as well on the design of the package.

Beatifull design work of Prakash Prakash also made a LED band, very elegant board design and impressive alluminium casing.

So I could not find and exact match to my project, where the aim is for a small band with bluetooth connection that could vibrate and register gestures. Still I find the casing desings inspiring, teaching me that with some effort a beautifull device can be made.

For the connection part, I know I want to use the RN4871 Bleutooth chip. Many people used this device in their networking week. Most used the board that is provided, some used it as their own design. But seeing that more than 5 people have succefully created a board by hand soldering the components, inspires me to use this chip and try to solder it myself. Some examples: Darle used the board for his networking week Ivan made his own board Still from Natalie I learn that I really need to be carefull soldering, removing such a chip with a heatgun is very difficult. Soldering this board took Natalie 3 tries

What questions need to be answered?

Wow will it be evaluated?

  • Is there effort made to make everything by myself?
  • Is there a substractive technique used?
  • Is there an additive technique used?
  • Is there electronics design and production technique used?
  • Is the microconroller interfaced and programmed?
  • Is there a system (combination board and app)?
  • Is the system packaged (casing for the microcontroller)?
  • Is it documented?
  • Are the files available?
  • Are there things to improve?

  • Is there a working board?
  • Is there effort made to make it small to wear on the wrist?
  • Can it vibrate?
  • Can it detect user input using the accelerometer?
  • Can it transmit data to the Smartphone via Bluetooth?
  • Can it receive data from the Smartphone via Bluetooth?
  • Can it run without a connected power cable?
  • Can the app send data to the microcontroller via Bluetooth?
  • Can the app receive data from the microcontroller via Bleutooth?


I still have a lot of work to do. While I am eager to make a fully working and nicely packaged smartband,
I feel it might be a little bit to ambitious.
I will probably drop some of my requirements when the deadline comes closer, making sure I have a working devide at the end of the run.
I will prepare my work, family and friends that the month of June is Fabacademy month.

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