While there are relatively cost-efficient solutions to measure and log temperatures during roasting, all available options to classify the resulting roast color seem to be out of reach for most smaller roasting facilities. We were asked for an automated alternative to the rather complex and inaccurate visual classification method based on a series of standardized color disks or the high-priced, laboratory-type measurement devices.
One day, Marko (the developer of the open-source roast logger Artisan) and Paul (a Human-Computer-Interface expert) came across an affordable true color sensor board and immediately ordered some samples. The evening they arrived one was connected to an Arduino and put into an Ikea box together with some quickly assembled LEGO construction to hold the coffee sample. Already that simple device was able to differentiate the presented roasts by color.
We were guided by a series of design principles to turn our initial prototype into a product.
Despite its clever design, we found a number of ways to improve our product thanks to new electronic modules becoming available. Our new Tonino features a bright OLED color display and wireless operation, using components from the startup TinyCircuits (Ohio, USA). All in a tiny package!
Respecting our design principles, we decided to realize the wireless charging base, using a novel innovative material from Germany. Kraftplex is a fully organic material, certified as safe even for children's toys standards. It is 100% cellulose, made from sustainably cultivated stocks of softwood, using only water, pressure and heat. No chemical additives, bleaches or binding agents are used in its production. We use a precision laser-cutting process by which we can put together all parts of our base without using any glue or additional screws.