The design principle of keeping everything to a minimum is also paramount in the Tamagotchi project. In this case, I wanted to use the Arduino chip itself and layout a board around it by myself and luckily, I also found out that my slaughtered external phone battery delivered 5.1 Volts which is in the operating range of the Arudino.
Top left, you see the front board with the display and the intended buttons (only one placed), top middle the board for the Arduino and it socket plus an USB port that will be used for the LiPo charger board (the one that is close to the battery) and on the right it’s the back plate containing the speaker and the RTC board. Continue reading