Climate Controller Based on PIC

Overview

The project utilizes SHT11 sensor to create a climate controller that reads temperature and humidity values which can be used for greenhouse control, small room climate control, food dehydrating, and hatchling warmer.

Explanation

During the measurement, the humidity readings can vary from 0 to 100% while the temperature scale reaches from -40 to 123°C. There are three distinct DC switched outputs with 10A load that can be handled by the controller board or it can be 2 DC outputs and one AC until 4A. The measurement and display of scale can be selectable between Centigrade and Fahrenheit.

The SHT11 sensor contains a 12-bit analog to digital converter for temperature conversion that results in a maximum resolution of 0.1°C while the humidity sensor uses a resolution of 12 bits. The controller board is responsible for reading the sensor, updating the LCD display, reading the rotary encoder, and switching the outputs. The AC control board provides the option of housing the power transformer and one switched AC output. The place of the heater DC output can be replaced if AC output is used.

The microcontroller used is PIC16F873 along with a rotary encoder with pushbutton.