Inventions

Off the clock, I build hardware for problems people live with.

Never my day job, always my own time. Microcontrollers, sensors, small models on small chips, and the software around them, built end to end. A few of them:

A contact-tracing and social-distancing ecosystem — without GPS.

The problem

As workplaces reopened during COVID-19, organizations needed to know who had been near a confirmed case — without tracking everyone's location.

A wearable bracelet that advertises itself over Bluetooth Low Energy and records proximity to other wearers — so exposure can be traced from who was near whom, not where anyone went.

The bracelet also reads heart rate and blood oxygen on-device. Contacts sync through an iOS app to a serverless AWS backend, with an immutable record kept on the IOTA Tangle.

There are two builds: a Lite version at roughly $8 in parts, and a Pro version at roughly $40 with health sensors and a display — cheap enough for an organization to hand one to everyone.

Edge AI that watches peatlands for drought and fire — and raises the alarm over LoRa.

The problem

Peatlands hold roughly 30% of the carbon stored on land. When they dry out and burn, they release it — and they usually burn far from any network or power.

A solar-powered sensor node that reads CO₂, soil moisture, and temperature, and runs a TinyML model on the microcontroller to classify the ground as normal, drying, or on fire — no cloud round-trip needed to decide.

Only the verdict travels: a small LoRa packet over the Helium network to a dashboard that alerts when conditions change. Low power and long range were the whole design brief, because the places that need this have neither power nor coverage.

Hearing substitution through haptics — so deaf parents can feel their child call for them.

The problem

Deaf parents can't hear a baby cry at night, and as children grow, everyday spoken requests become a constant communication gap.

A TinyML model running on the microcontroller listens for crying and tells it apart from background noise (about 85% accuracy in my testing). When it hears a cry, it sends a distinct vibration pattern to a haptic wristband the parent wears.

For older children, an iPad app with picture-based communication (AAC) lets a child say "I'm hungry" or "come here" — each mapped to its own dot-dash haptic pattern. The same device watches room temperature, humidity, and air quality.

Operate a shared keypad through augmented reality — without touching it.

The problem

ATM keypads, fuel pumps, and self-checkout terminals are some of the most-touched surfaces in public — and replacing that hardware is expensive.

Point your phone at the machine, and an AR overlay puts the keypad on your screen. Taps travel over MQTT to the microcontroller inside the unit, which behaves exactly as if the physical keys were pressed.

The point was retrofit, not replacement: the existing keypad keeps working, and the touchless path is added with inexpensive hardware. The working model covers it end to end — keypad, cash-dispensing servo, and a 3D-printed enclosure.

More from the workshop: my maker profile lives at iammithun.link.

All 34 builds on Hackster