Finally, the board works perfect. So I could make a 3D design for the case and this is a final product that could end up on Kickstarter. It is a very cheap project, around 15$ for all the parts . On this tutorial you willhave a full part list, the schematic and layout of the board in case you want to amke it. I also share the 3D STL files for the case so you could print it.

To supply it we use a type mini B USB connector. That is connected to the power MOSFET but also to some pads for the buck converter so we could get 5V for the other microchips. Now the 16Mhz crystal is smaller so we have more space on the PCB for future improvements. See version 2 to see the other PCB. We haev 2 push buttons to set the temperature and other settings, a vibration sensor for the sleep mode and the ATmega328p.AU microcontroller.