It is a two-point thermometer based on the processor Attiny2313 (Atmel) and Dallas sensor 18B20. In fact, these are two separate thermometers in one housing, so 2 processors were used.
The displays are connected to the control electronics through a border with HEADERS. The front panel was made in Gimp. It is a perfect tool for this purpose, because the the dimensions and location of the objects can be precisely defined in commonly known units, not e.g. in pixels. LED is used to display negative temperatures as a minus sign.
Elements used:
Attiny2313 x2
housing
displays x6
resistors
capacitors
transistors
The temperature sensor in the external thermometer was not derived outside the house, so both the indications are now the same.