CapperLabs Greenhouse Controller Table of Contents |
|---|
| Blog 1 Introduction |
| Blog 2 System Components |
| Blog 3 Intel Edison |
| Blog 4 Grove-y |
| Blog 5 Round and Round |
| Blog 6 Automatic Vent |
Getting back to the Greenhouse project, my first sub-system to control is the window vent.
The greenhouse came with two vent actuators, one manual, and one automatic based on internal temperature.
The automatic opener works ok, but can't tell if its raining outside and the opening temperature can't be adjusted.
Here's the original assembly:
The unit operates using a cylinder containing a wax mixture that expands with increased temperature.
My goal is to replace the cylinder with a screw drive and stepping motor.
This is the screw drive I removed from some old equipment:
Modifications are needed to adapt the screw drive brass bearing holder to the lever arm:
After a few hours of cutting/grinding/pulling hair out/swearing, and a bandage or two, the screw drive is complete:
The screw nut is attached to the end of a brass pipe so I can get about 3 inches of travel to allow the actuator arms to open fully.
The pipe was used to allow the screw to close the actuator without traveling out the end of the unit.
Now all I need to do is attach the stepper motor to the screw shaft and connect it to a motor controller.
The Edison will control motor microstepping and direction. I may need to add limit switches also, since there isn't any location feedback.
The SeedStudio motor shield doesn't work with the Edison Arduino board - probably not enough GPIO drive current. I may use an aux Arduino to run the motor and send commands from the Edison. Here's a short video of the Arduino controlling the stepper motor.
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