With the Arduino-enabled Smart Citizen Kit, citizens can record real-time environmental data which can then be used for research, analysis and, eventually, citizen-led solutions to environmental problems. The Smart Citizen Platform connects data, people and knowledge for researchers, schools, citizen science, communities, cities and developers to collectively address environmental problems in cities. re are two main strands to the project: the Smart Citizen Kit, a low-cost set of tools which uses Arduino technology to allow citizens to collect environmental data on light and sound intensity, temperature, humidity and concentrations of CO and NO2 in the air. This data is then transmitted by wifi to a server where aggregated data can be researched and analysed. The Kit can be built upon by users to measure other environmental factors. The second strand, the Smart Citizen Platform, lets researchers, schools, communities, citizens, cities and developers connect with each other.