Thermocontroller

Based on ATmega16, MAX6675+K-thermocouple, 4 buttons, 3x7-segment indicator.

Simple themocontroller. Features: Work modes

1. Relay mode (TODO)
2. Hysteresis mode.
3. PID mode (Default)

Engineer menu: Hold ESC key during boot sequence. Schematics and PCB: https://easyeda.com/gurevoleg/retorta