There is a very particular citizen workgroup at Citilab called Nous Artesans (New Artisans). It is a very heterogenous group, formed by people with very different backgrounds, ages and skills, but with a common interest in tinkering and building things.
take stuff apart > understand how it works > build new stuff
Their latest workshop consists in building a miniature model of a Smart City, for which they needed to build a free parking spot counter, so we did that for them by using S4A:
###By means of a 7-segment decoder
###By using digital and analog outputs
All code and datasheets can be found inside this package. Enjoy!