I know I haven't posted in awhile. I have been planning some major revisions to my original design(s).
I'm excited to get to work on it. I've changed some of a project parameters as simply logging data isn't enough to grow plants reliably on a window sill. There are too many congruent variables affecting optimal plant growth. To mitigate those, I think a few major workarounds are needed.
So, I've decideded that a camera with a Raspberry Pi Zero to provide visual plant logging to the setup is an important component. It provides visual feedback and allows you to gather visual data on how individual plants are doing.
I'm going to setup two separate systems. Then I'll set 'em both up so I can evaluate the benefits and drawbacks for each.
What that means is that I will likely be setting up a cable system connected to a couple of stepper motors to move the camera to selected plants and photographing each plant individually. I've elected to utilize NEMA 17 stepper motors as I am familiar with them via 3D printing.
Essentially, I'll be borrowing the concept from Delta configuration 3D printers to move a Pi Zero and camera on a yoke to photograph each plant up close. All I'll need for this are stepper motors for the Z and X axis.
However, I will likely setup a smaller single axis test platform using smaller japanese stepper motors for smaller stackable planters. This will retain the original project goals of using an esp8266, solar power and low power overall objectives. It likely won't have a camera setup.
The idea general idea is thus:
Camera and Pi Zero move to each plant, deposit a soil moisture probe then trigger a small peristaltic water pump to water the plants from a water reservoir connected via a small flexible tube at the base of the rig. The Pi camera will also house the temperature/humidity and light sensor.
More importantly however, I will likely be setting up the two systems with a way of piping cool or warm water (comparatively to soil setup on a window in direct sunlight) from a water reservoir held at room temperature with a UV light to kill bacteria.
Overall, I think these are the bare essentials that will be needed to grow edible plants on your window sill in a disparate variety of climates. I could muck around with adjustable window shades and the like, but I really want maximum natural daylight before having to power full spectrum LED lighting in the future.