While until now we had mostly considered the hardware side of things we did not spend too much time on another crucial aspect of creating a connected device: The application and firmware!
While we knew from the beginning that we wanted to use the Arduino firmware to program our microcontroller we actually kept the application aspect rather open. Finally we decided to program for Android rather than iOS because of the Open Source nature of the project and because we did not want to bother with the licensing structure for Apples development environment. As nobody in our group had ever programmed an App for Android we were looking for solutions that would allow us to quickly draft a prototype for the application, and we found one: The MIT App Inventor!
The MIT AppInventor User Interface
Because our microtechnical engineer was still pretty occupied with the PCB layout our mechanical engineer, Florian L., decided to jump in and learn how to design a mobile application and did a great job by going through all the tutorials and step by step building our smartphone app that would finally make our device a connected device!
Screw : Finally, after looking at different bottles we decided to design our connections between the 4 pieces (the bottle, the nipple, an upper screw to close the bottle and hold the nipple and the cap) in the simplest way possible:
The screw of the upper ring has been design so the user only have to do ½ of turn to lock the bottle. It is thus easier to handle while taking care of a baby. For the connection between the bottle and the device we have chosen a simple screw with only a ¼ of turn so it is easy to handle as well.