Electronic Accessories by Koli



1. LED Coin Purse

Description – LED coin purse is an electronic accessory that reminds the user to close / button the purse once they keep the coin inside. The coin purse has a small LED attached on one side, which lights whenever the purse is opened. This brings the user’s attention to close their coin purse before coins / money is misplaced.

Discussion – I would like to make a larger version of this bag with more LEDs that light up once it is opened, reminding the user to close it. Also, I would like to embed the circuit inside the purse so that the breadboard and Arduino is not out in the open. This reduces the aesthetics and usability of the bag.

Process and functioning – The bag has a copper taped button hole along with an aluminium button. Both of them are connect to the digital and ground pins respectively.The functioning is controlled by an Arduino Nano 33 iot. Once the button is attached to the button hole, the circuit is closed, this turns OFF the LED.


Code – https://github.com/Krishnokoli/Body-Centric-Technologies/blob/main/LED%20Coin%20Purse

Circuit diagram –





2. Pulsing Heart Brooch

Description – The Pulsing brooch is a wearable LED jewellery that is supposed to be worn on the shirt, blouse or any upper torso garment. The heart brooch has a unique capability of Pulsating once the area around it is touched by the wearer. This gesture is to convey the emotions of ‘Love’ or ‘Gratitude’ by the wearer. Since, we are socially distancing during the Pandemic, this jewellery can help create better interpersonal relationship between the wearer and their audience. This brooch is created with the help of an LED Matrix. The normal mode for the brooch is a LED heart display, on touching the area surrounding it, the LED heart patterns begins pulsating.

Discussion –  The prototype is to be improved further so as to create a more sleek brooch, which can come in different shapes, not simply an led matrix. I would also like to introduce other emoticons or icons to convey other emotions, triggered by different actions. I also want to place the push button onto the brooch, instead of putting it on the underside of the shirt (which was placed for the convenience of display).

Process and functioning – The brooch has two parts which are an led matrix and a push button. The push button, when turned ON, activates a pulsating pattern on the heart in the LED Matrix. The functioning is controlled by an Arduino Nano 33 iot. Below is an open demonstration of the circuit.

Code – https://github.com/Krishnokoli/Body-Centric-Technologies/blob/main/LRED%20Pulsating%20Heart%20Brooch

Circuit diagram –




3. LED Colour Transpose Bracelet

Description – This bracelet is an electronic wearable designed to change colour once it is secured on the user’s wrist. The colour values keep changing randomly at a regulated time interval, when the magnetic button is secured in place. On opening the button, however, the colour change pauses at the very last tone. The button attachment completes the circuit, hence it is like a digital button that initiates the colour changing functionality.

Discussion – I was inspired by pearly bracelets to create this piece, and would like to improve the aesthetics further by adding pearl beading on each led point. I was also confused about how to switch off the LED strip completely once the button was taken apart. Let me know if you know a code that could help me turn off the LED, when the digital button circuit is open.

Process and functioning – The LED Colour Transpose Bracelets have an two magnetic buttons placed on two ends of the bracelet along with the LED strip placed between them. The LED strip consisted of individually addressable 5V lights that were directly connected to the Arduino Nano 33 iot. The buttons were connected from- digital and ground. When they were connected, the circuit was closed and the LED strip was programmed to change into random colours at regular selected intervals.

img_20210222_160811     circuit

Code – https://github.com/Krishnokoli/Body-Centric-Technologies/blob/main/LED%20Colour%20Transpose%20Bracelet

Circuit diagram –


Traffic Control Wristband



Traffic Control is a very necessary but difficult job, especially due to the harsh weather conditions, anywhere in the world. Lack of integrated lighting systems and heavy gears add on to the professional hazard for traffic controllers everyday. While reflective clothing is very effective in such circumstances, an additional lighting mechanism could improve their signalling and visibility to vehicles on the road. Designing an integrated wrist accessory for easy traffic control was the initial concept behind conceiving this project.

The wearable is a simple wristband with 2 finger attachments. The wristband holds the LEDs, which can change patterns depending upon the signal the controller wants to display. Currently, the wearer can only display 2 signals – ‘Blink’ (Stop) and ‘Direction’. The device has an auto turn on/off. It functions only in the absence of sunlight, hence conserving energy.

The device runs on Arduino Nano 33 iot. A touch sensor and photo resistor are also added to the circuit. The touch sensor help detect the wearer’s haptics, and change the lighting patterns accordingly. The photo resistor which sits right on top of the wristband, helps detect the sunlight, allowing the device to turn on/off without any physical stimuli.

While the idea was to design a product which could be extremely lightweight and sleek, integrating well with the wearer’s uniform, currently the primary prototype is bulky and wired. More research and development will be required to make a more compact version of the device so that it could be easily worn everyday.

Experience Video

Idea and Process






Link To Code



The primary idea behind the project came from a small road trip to the outskirts of my city. While travelling back home, at night, the traffic controllers  in the crossings wielded red and green traffic control batons. Hence, I thought of integrating the lights onto the arm through a small LED lit wristband that would not involve holding an added accessory for long hours.

After coming up with an initial concept I decided to do some research on wrist wearables so that I could find some inspirations to carry out my project.

  • FingerTrack – useful

The first project that seemed very interesting was ‘FingerTrack’. It was developed by researchers from Cornell and the University of Wisconsin, Madison. They designed a wrist-mounted device that continuously tracks the entire human hand in 3D. The bracelet, called FingerTrak, can sense and translate the many positions of the human hand, including 20 finger joint positions, using three or four miniature, low-resolution thermal cameras that read contours on the wrist. The researchers added that the device could be used in sign language translation, virtual reality, mobile health, human-robot interaction and other areas. I find that the finger tracking technology could be really useful for my idea of developing the ‘Traffic Control Wristband’ without the use of touch sensors.

• MICA (My Intelligent Communication Accessory)

A project with a really interesting aesthetic appeal is the MICA. Developed by Intel, MICA has transitioned from the very androgynous aesthetic of ‘Fitbits’ and ‘Apple Watches’ to that of a High Fashion ‘feminine jewellery’.

•  Guardian Angel

Another example of a brilliant project with a little problematic aesthetic is ‘Guardian Angel’. This necklace has been designed by the agency – JWT Singapore. The concept for this product is very interesting and useful. A single click on the jewellery automatically triggers a call to a woman’s cell phone, so she has a convenient excuse to walk away from unwanted attention at public places. If things change from annoying to dangerous, holding down the button sends an emergency message to a friend with the victim’s exact GPS coordinates. Now, although usefulness of the device is no doubt really well thought out, the aesthetics of the jewellery makes it look like a silver insect. Also, there are mobile apps that enable the user to do fake calls to excuse themselves out of problematic situations.



I look forward to work further on this device and develop it into a more compact and user friendly wearable.


The Cut. “Can Opening Ceremony Make Wearable Tech Cool?” Accessed February 2, 2021. https://www.thecut.com/2014/11/can-opening-ceremony-make-wearable-tech-cool.html.

Cornell, Information Science. FingerTrak – a Wrist-Mounted Device That Continuously Tracks the Entire Human Hand in 3D, 2020. https://vimeo.com/440359313.

Hu, Fang, Peng He, Songlin Xu, Yin Li, and Cheng Zhang. “FingerTrak: Continuous 3D Hand Pose Tracking by Deep Learning Hand Silhouettes Captured by Miniature Thermal Cameras on Wrist.” Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies 4, no. 2 (June 15, 2020): 1–24. https://doi.org/10.1145/3397306.

Lee, Sid. Intel & Opening Ceremony | MICA Launch, 2014. https://vimeo.com/108266159.

“MIT: Wearable Tech: New Wristband Device Can Detect Emotions in Real Time – The Economic Times.” Accessed February 2, 2021. https://economictimes.indiatimes.com/magazines/panache/wearable-tech-new-wristband-device-can-detect-emotions-in-real-time/articleshow/58803657.cms?from=mdr.