What it is?
Right now, not much… but soon I hope, a set of plans and software to continuously monitor plant + pot weight during growth.
The idea is that I will combine a scale, solenoid valve and microprocessor to accurately determine when individual plants need to be fed. As a basic idea of the procedure, the cannascale will record the saturation weight of the plant + pot at every feed, and then monitor the weight of the pot as the liquid in the medium is consumed and perspired by the plant. Once the weight drops below a threshold value, the feed cycle initiates again.
For growing in coco coir, I expect this to be a superior method to simplistic time-based feeds. The risk of pots drying out will be negated, and individual plants will receive personalized attention as they need it.
As a side benefit, I should also be able to extrapolate the change in plant weight during growth. That’s a nice bit of data to have. If I can combine this with environmental monitoring (temperature & humidity), then the length of the feeding cycle should have some correlation with VPD.
For now, I’m just going to make due with parts I had laying around to build the scale. This is just a aluminum sheet I had from an old 3d printer, and some aluminum T-slot.
The weight will be measured using a piezo-based weight sensor… common elements in bathroom scales, etc. I went with a 10kg sensor. These can be sourced on ebay for a few bucks, with their respective amplifiers.
I also have some solenoid valves that will need to be switched with relays or transistors. I’m going to save that until later, and start by just monitoring the weight. Just having data to look at will help me to know the feasibility of the project, and might provide some early insights.
Next stop is to work on getting the electronics up and running…