Climate Controller Designed with PIC

Overview

The Sensirion SHT11 sensor is utilized by this climate controller in order to read the temperature and humidity measurements simultaneously.

Details

The measurement and display scale of the climate controller can be selected between Centigrade and Fahrenheit as the temperature measurement ranges from -40° to 123°C and humidity is 0-100% temperature compensated. Some of the uses of this device include food dehydrating, hatchling warmer, small room temp/humidity control, and Greenhouse temperature/humidity control.

The three distinct CD outputs with 10A load or 2DC outputs with one AC up to 4A are managed by the controller board. It also reads the sensor, switches the outputs, reads the rotary encoder, and updates the LCD display. The controller board can be used as a standalone device if temperature and humidity readings only are required.

The sensor uses the combined humidity and temperature sensor SHT11 from Sensirion which comes in a SMD package. It is designed from a double sided PCB so that the more obtainable and handy 8-pin DIP carrier version is allowed to be used. A 14-bit analog to digital converter is contained in the sensor for temperature conversion which results in a maximum resolution of 0.1°C.