With this project you can show the temperature on you PC. This thermometer plugs in on any free serial port. It gives temperature readings accurate to 0.5°C with no calibration.The project consists of the ATTiny2313 RS232 board and the DS1621 Thermometer board and software for the PC. It can display both indoor and outside temperature on the PC screen (see picture below).
The DHT11 sensor is made of two parts, the capacitive humidity sensor and the thermistor. There is also a basic chip inside that converts the analog signal to a digital signal with the temperature and the humidity.The digital signal is easy to read using a microcontroller. The result is shown on a LCD display.
This small thermometer board can be connected directly to PORTD of the AVR 2313 Project board. It uses the Dallas DS1621 Digital Thermometer and Thermostat chip. The DS1621 measures temperatures from -55° to +125° in 0.5° steps and doesn't need calibration or external components. It has also a build-in thermostat with high and low set-points which can be programmed by the user.