Automatic greenhouse window opener

[Rhys]

Hello,

I’m currently trying to create an automatic system to either open or close the door/window of a greenhouse dependent on the internal temperature. For example, if the actual internal temperature is lower than the set point, the window will close a set distance dependent on the temperature variation between the ideal and actual temp values.

The problem I am facing now is what kind of system to build to address this. The solutions I think could be used are:

· PID temperature controller

· Arduino, and code the system, with inputs of a set point and temp sensor

I will then 3D print a rack and pinion to attach to a motor that is driven by either the PID or Arduino system.

If anyone has any suggestions as to which would be the best system to pursue, or a whole new idea entirely I would be keen to hear them. Thank you for taking the time to read this and I would be very grateful for any feedback or help.

Many thanks

R

 

[kellys_eye]

Maybe something simple like a servo-actuated cam, the servo position being set by a PWM circuit that has a thermistor as part of its timing circuit perhaps?

Many RC model servos have sufficient power to turn a decent sized cam that could be used to 'lever' a window open. Such servos are driven by a simple pulse modulation circuit - the position of the cam depending on the width of the received pulse.

Even the humble 555 can produce such a pulse and with one of the resistive timing elements selected from a suitable thermistor the cam position is then temperature dependent.

Simple and easy to produce - make a half dozen and fit one to a load of windows. Maybe even use a solar cell to power them (self contained) ????

Just an idea.

 

[Rhys]

That's a good idea! Gives me another solution to consider thats a bit simpler.

Many thanks for replying

 

[Minder]

Linear actuator?
M.

 

[Rhys]

Would the linear actuator be connected to a PID so that it automatically actuates dependent on temperature variance from the set point, or would a different system be used?

 

[Minder]

PID implies some kind of feedback element.
M.

 

[Rhys]

So my goal was to use a temp sensor for measuring the internal temperature of the greenhouse, depending on the variation of the actual temperature to the setpoint value (Temperature I want the greenhouse to be) the motor will be driven to either open or close the window incrementally to get the actual temperature to the setpoint value. So that’s where I thought I might need a PID for the feedback element.


Many thanks

R