Introduction: Tighten Your Belt!

About: A critical making project designed by 3 graduate students at The Faculty of Information, University of Toronto.

Welcome to our Instructable!

This Instructable provides a guide to creating Tighten Your Belt- a wearable technology. Tighten Your Belt is a device that displays your expenditure using 5 LEDs. The LEDs are activated with a pushbutton. In order to illuminate 1 LED, the button must be pushed twice. Each push of the button represents a value that has been decided from dividing an individual's daily budget by 10 (the total number of pushes it takes to illuminate all LEDs). For instance, if one’s budget for the day is $50, the individual would divide $50 by 10 therefore leaving each button push to represent $5. If the individual has spent $20, they would press the button 4 times to input a $20 value and 2 LEDs would be lit.

Tighten Your Belt was our final project in our class Critical Making. For the project we were told simply to "build a wearable system that reveals private information in public space."

As we began brainstorming with the caveat of making private information public, we realized how little information is still considered private. There are already systems in place to share virtually anything online: from your calorie intake and exercise to your GPS location. We began to ask ourselves, what are the few things we still keep private? Finances!

David Phillips, one of the authors we read in our class, put forth the notion that "identity is always social" (Phillips, 2009, p. 303). With this in mind, our project is an attempt to understand how divulging one’s spending information can impact his/her social relations and/or identity. We are continually exposed to information that was once considered private, with the increasing use of social media sites and various wearable technologies. Discussing financial information is a topic that has yet to make it into the realm of information-sharing. Phillips (2009) discusses that identity is negotiated and coconstructed around one’s surroundings. He suggests that we become who we are in relation to others. Furthermore, Phillips discusses that people shape their identities based on how they are treated. By building a tool that displays financial information, we intend to learn more about this concept by pushing the boundaries of information sharing behaviours.

In this step-by-step guide, along with the technical direction, we aim to explore social construction and identity through the materiality and making process of Tighten Your Belt.

Step 1: Materials

To build this device you will need hardware materials, software materials, a few tools and some helpful scholarly texts .


  • Arduino Uno
  • Computer
  • Small Breadboard
  • 5 LED Lights- 2 Green, 2 Yellow, 1 Red
  • 9 Jumper Cables
  • 5 (five) 330 Resistors, 1 (one) 10k Resistor
  • 1 Push Button
  • 1 USB Cable
  • One 9V Battery with battery snap and a 2.1mm barrel (if you would like your device to be battery powered)


  • Arduino Program
  • Tighten Your Belt Code


  • Plastic Soap Dish
  • Belt
  • Coloured Tape
  • Foam


  • Exacto Knife
  • Duct Tape
  • Glue gun


  • DiSalvo, C. (2009). Design and the Construction of Publics.Design Issues, Vol. 25, No. 1: 48-63
  • Latour, B. (2008). A Cautious Prometheus? A Few Steps Towards a Philosophy of Design (with Special Attention to Peter Sloterdijk). Keynote lecture,Networks of Design, Falmouth, Cornwall, Sep. 3, 2008. Available at:
  • Ingold, T. (2010). The Textility of Making. Cambridge Journal of Economics. Vol. 34, No. 1: 91-92.
  • Phillips, D. J. (2009) “Ubiquitous Computing, Spatiality, and the Construction of Identity: Directions for Policy Response,” in Ian Kerr, Valerie Steeves and Carole Lucock (eds.), Privacy, Identity and Anonymity in a Network World: Lessons from the ID Trail. New York: Oxford University Press.

Step 2: Assemble Hardware

Let's begin by assembling the hardware materials.

Connecting the LEDs

  1. plug the USB cable into the Arduino and into the computer
  2. plug the 5 LED lights into digital pins 2, 3 (green) 4, 5 (yellow) and 6 (red)
  3. connect a jumper from digital GRND to breadboard
  4. plug 5 jumpers from digital pins 2-6 on Arduino to longer LED legs on breadboard
  5. plug 5 resistors from GRND on the breadboard to the shorter LED legs

Connecting the Push Button

  1. connect power GRND to breadboard
  2. use 10K resistor to connect GRND to one leg of push button
  3. connect digital pin 12 to same pin of push button
  4. Connect power 5V to opposite leg of push button

The colours chosen are intended to create a visual representation of the money spent. Green, yellow and red have universal connotations, especially when shown in sequence. In this configuration, green indicates that one is within the allotted budget, yellow means that one is nearing the limit, and the red LED indicates that the budget has been spent. This is an interesting way to make the information this device portrays, more explicit. Due to the difference in colours, various assumptions can be made by others who see the information. In this step we worked through DiSalvo's idea of projection in the ways that the design of this device in regards to the colours chosen, can represent a set of future consequences. Each colour of LED sends a different message. For example, having a green LED lit can exert a sense of 'safeness', yellow a sense of caution and red a sense of alarm and even danger. Designing the device in this manner allowed us to learn that technologies in different spaces can have an affect on the types of interaction and social relations that individuals who wear this device may encounter.

Step 3: Software

Next, let's assemble the software materials.

  1. open your Arduino program
  2. copy and paste the code provided below into the blank sketch
  3. upload the code by clicking the arrow
  4. test to see if your code functions accordingly


int buttonPin = 12;
int LED1 = 2; int LED2 = 3; int LED3 = 4; int LED4 = 5; int LED5 = 6; int buttonreading; int previous = LOW; int count=0;

long time = 0; long debounce = 300;

void setup() { pinMode(buttonPin, INPUT); pinMode(LED1, OUTPUT); pinMode(LED2, OUTPUT); pinMode(LED3, OUTPUT); pinMode(LED4, OUTPUT); pinMode(LED5, OUTPUT); Serial.begin(9600); } void loop() { buttonreading = digitalRead(buttonPin); if (buttonreading == HIGH && previous == LOW && millis() - time > debounce){ count++; } previous = buttonreading; if (count == 0){ digitalWrite (LED1, LOW); digitalWrite (LED2, LOW); digitalWrite (LED3, LOW); digitalWrite (LED4, LOW); digitalWrite (LED5, LOW); } if (count == 2){ digitalWrite (LED1, HIGH); } if (count ==4){ digitalWrite (LED1, HIGH); digitalWrite (LED2, HIGH); } if (count ==6){ digitalWrite (LED1, HIGH); digitalWrite (LED2, HIGH);q digitalWrite (LED3, HIGH); } if (count ==8){ digitalWrite (LED1, HIGH); digitalWrite (LED2, HIGH); digitalWrite (LED3, HIGH); digitalWrite (LED4, HIGH); } if (count ==10){ digitalWrite (LED1, HIGH); digitalWrite (LED2, HIGH); digitalWrite (LED3, HIGH); digitalWrite (LED4, HIGH); digitalWrite (LED5, HIGH); } if (count >=11){ count = 0; } Serial.print(count); }

Step 4: Prepare Enclosure

Once you have verified that your code works, it will be time to prepare your enclosure.

  1. Feed belt through slits in soap dish (our soap dish already had slits, but you could always make your own!)
  2. Cut a rectangular section out of the top of the soap dish that is long enough to expose the five LEDs and button
  3. Cover the rectangular cut-out section with duct tape and make a slit across the centre that is the length of the LEDs (this ensures that there is a tight fit for your LEDS)
  4. You may choose to put a piece of dense foam, or similar material, to close the gap between the button and the tape
  5. Decorate to your hearts content! We started covering our enclosure with black electrical tap to match the black belt.

Why a belt?

As Ingold argues, objects can "act back" (Ingold, 2009, p.94). What this means, is that objects are not merely manipulated by human hands, they in fact manipulate the actions of humans. For example, we first took the idea of a "wearable" system quite literally. We envisioned our device as a piece of clothing. We first planned to make a T-Shirt that would have the LEDs displayed boldly across the chest. As moved from the conceptual brainstorming phase and into the building phase, however, we soon realized that this idea would be impractical in its execution. Firstly, the Arduino and breadboard would be bulky and heavy and hard to secure to a T-Shirt. Secondly, a T-Shirt would need to be washed on a regular basis, adding a further complication to the design. We started to think of ways that would be easier to fabricate and more practically to wear on a daily basis. This is when the belt idea came in!

Step 5: Using Your Device

It's now time to put your device to use!

  1. Take your daily budget and divide it by 10, this will decide the increment represented by each button push. For example, if your budget is $50/day, $50 divided by 10 = $5. Therefore, each button push represents $5 spent.
  2. Once you’ve pressed the button 10 times, your budget is maxed out for the day, pressing the button an eleventh time will reset the counter for the next day.

In "A Cautious Prometheus," Latour sees one advantage of the word design being the ability to raise the question of the good and bad. He says when we design something there is the involvement of an ethical dimension which prompts one to ask if this device is good or bad. (Latour, 2008, p. 5). Working through Latour's work, the building of this device and the components included can enable us as designers to ask those same questions. Allowing users to present their level of spending in a public space can foster interesting interpretations by the public. This can allow people to be judged based on their lights, presenting a case for both the good and the bad.

Why an LED graph?

The choice of the LED graph is another example of Ingold's notion of objects' capability of acting back. Obviously, when we first began thinking of ways that we could display financial information in a public space we had much more elaborate ideas than a simply LED bar graph. Wouldn't it be neat have a program hooked up to your online banking that showed a running total of what you had spent that day? Of course it would. Unfortunately, this was not within the scope of the class or our programming talents. We had to work with our amateur skills and a somewhat fixed set hardware. Of course, now that we see what we have built, it is now more interesting. The simplicity of the LED bar graph adds a level of ambiguity of interpretation. People viewing Tighten Your Belt can now speculate on what a wearer's budget is. If someone reaches the red LED day-after-day, are they perceived as financially irresponsible? Or big spenders? Would your opinion change if you knew what their daily budget was? It is interesting how counterintuitive it is that we often interpret wealth by the amount of money a person spends, rather than what they save.

Step 6: Reflection

Now you can tighten your belt!

Future builds of this technology may include automatic deductions as you spend your budget depending on the method of payment. We intentionally created this build to be a manual manipulation in order to align this approach with current information sharing patterns that occur via channels such as social media sites and other wearable technologies. We took into account the voluntary aspect of information sharing and tried to create a platform that users can be expressive at their discretion.


1. We initially wanted the wearable device to be embedded in one's shirt. However, we decided to use a belt to allow versatility and self expression by means of decorating the wearable technology.

2. As a group, we discussed displaying one's spending habits in numerical form. After careful consideration, we settled on using LEDs to represent the numbers as this is a more abstract approach. We felt this was more interesting in contributing to the idea of social construction that we were working with. Promoting ambiguity through the representation of LEDs leaves room for interpretation of those receiving the information. We did not feel that one would be comfortable displaying a dollar value as this is a less personalized option.

Critical Making - Our Design Process

According to Matt Ratto, "The use of the term 'critical making' to describe our work signals a desire to theoretically and pragmatically connect two modes of engagement with the world that are often held separate – critical thinking, typically understood as conceptually and linguistically based, and physical ‘making’, goal-based material work." (Ratto, YEAR, p.3). When building this device, we worked with the conceptual ideas of the various authors and discussed elements we found interesting, challenging and troubling to use materials and build something that helped us to better understand private information in a public space. We take away some intriguing insights and some extremely beneficial fascinations that the connection of conceptual and physical helped to facilitate.

For our design process we used Disalvo's concept of "projection" (DiSalvo, 2009, p.52) . We projected the different scenarios that may occur as a result of our technology. Because we are not familiar with technologies similar to Tighten Your Belt, we cannot predict its social consequences. This is an experimental method of learning through design. Furthermore, we incorporated Latour's (2008) use of the term "design" (p.3). During our making process, we considered the practicality of its use. We took into consideration the wearer of the technology and designed it to be easily incorporated into one's daily outfit. So far, we believe this is a 'good' design. However, after its implementation we predict further feedback from the public concerning its wearability. Finally, we understood that displaying financial information is a private matter, therefore the ethical dimension also played a role in our decision to render it a manual option.


  • How are you perceived by the public when wearing this device?
  • How does the voluntary compliance nature of the device play into interpretation?
  • What type of person would want to wear this device?
  • How does this device affect your spending habits?