Firmware for thermostat based on Atmel microcontroller with a DS18B20 temperature sensor and a relay.
Tested with ATmega8L.
Web-interface to control settings - https://github.com/Forever-Young/thermostat-web
MCU is connected by a standard scheme, without external oscillator.
Relay is connected to PC4 pin.
DS18B20 is powered with external supply (not parasite-powered).
Control by UART pins PD0, PD1, 9600 8N1.
- Protocol:
- 't':
- Return current temperature. Temperature in deciCelsius.
- 'c':
- Return current state ('1' - on, '0' - off (logical, not dependent on parameter NORMALLY_OPEN_RELAY), '.' - not changed).
- 's':
- Set boundaries - 'sh' - set high boundary, 'sl' - set low boundary. Eg. 'sl215 ', 'sh220 ' (space or newline is required after number).
- 'g':
- Get boundaries, 'gh', 'gl'.
- 'b':
- Hard-reset of controlling device (not tested!). Pin PC5.