iainmacpherson / temp-and-humidity-controlled-actuator

Control an actuator based on the temperature or humidity using Arduino

Temp-and-Humidity-Controlled-Actuator

Note: this project was just to mess around with the hardware, it is not finished and not likely to be.

Description

Using an arduino, control a linear actuator based on the temperature and humidity detected by a connected sensor.

Components:

• 12VDC Power Supply
• Arduino Uno
• 2 Channel Relay
• Temperature and Humidity Sensor. (Product page)
• Actuator (12VDC with max. 10A current draw). (Product page)

Wiring diagram

Image from the project by Progressive Automations detailed here.

Required Libraries:

• DHT sensor library

Project Files

• binary_actuation.ino is the example provided by Progressive Automations. It extends or contracts the actuator between fully open and fully closed in response to a comparison with a heat index threshold.
• feedback_actuator.ino is an implementation that uses the temperature and humidity sensor as feedback for actuator, driving it in the direction so as to reduce the error between the measured temperature and humidity and the target temperature and humidity.

Functionality

The actuator is controlled with a negative feedback loop and make it settle in some intermediate state between open and closed that keeps the temperature and humidity near the target values. The state will be continuously controlled by the loop to react to changes in temperature and humidity that may occur.