2023, penultimate year of school. We built affordable, portable monitors that warn asthmatics and allergy sufferers before the air in a room turns against them.

I am asthmatic. The idea arrived during an attack at 2am, with no way to know what had changed.

RP2040 microcontroller, GP2Y1014AU optical dust sensor, PM2.5 detection down to dust, mould, and pollen, and an LED that turns red past threshold. Boards soldered by hand in the school lab; enclosure drawn in CAD and 3D printed to keep the unit cost near nothing.

Bootstrapped by selling merchandise at the Christmas fair. Five units sold at London trade fairs, Spitalfields among them. The VP of a components distributor followed our work; a venture firm tried to enter us into its startup competition, then learned we were under 18.

Built alongside full-time school, which is where I learned electronics, CAD, and how to hold a team together.