Lab notes #1: an autonomous aeroponics system, currently a breadboard
What's on the bench, why high-pressure aeroponics is the hard version of hydro, and the safety-first plan for a grow system that runs itself.
Let's be honest up front: Jardin is currently a breadboard. A very ambitious, very messy breadboard, with wires going places wires shouldn't go. This series is the story of turning it into something you'd trust with your plants.
What's on the bench
| Part | What it does |
|---|---|
| ESP32 boards | The brains of each node. Cheap, Wi-Fi built in, plenty fast |
| pH and EC/PPM probes | Measure the nutrient solution, the two numbers that matter most |
| Temperature and humidity sensors | Air, root chamber and water temperature |
| Peristaltic dosing pumps | Add nutrients and pH adjusters in measured amounts |
| Pumps and solenoid valves | Move water and fire the misting zones |
| Flow meters | Prove water is actually moving |
| Load cells | Weigh the reservoir and the stock bottles |
The load cells are the secret weapon. Weighing the reservoir tells us how much the plants drink each day, catches leaks (weight dropping when nothing is running), and lets the system mix a fresh reservoir by weight. Weighing the stock bottles means every dose is verified in grams, not just "the pump ran for 4 seconds, probably."
Why high-pressure aeroponics
In high-pressure aeroponics (HPA), roots hang in a dark chamber and get misted with a fine nutrient fog every minute or two. Roots get loads of oxygen and growth can be fast. It's also the least forgiving way to grow: if the misting stops in a warm chamber, roots start suffering within tens of minutes.
That's exactly why we want to automate it properly. Our design rules:
- The firmware has hard limits the software can't override. Maximum pump run times, pressure ceilings, dose caps. If anything goes weird, the hardware says no.
- Misting never depends on Wi-Fi or the cloud. If the hub dies, the node keeps misting on its last plan. If the power dies, a battery keeps it going.
- Two ways to know it's working. Pressure drop on every mist burst, and humidity inside the root chamber. If either looks wrong, it switches zones, flushes, and alerts you.
- A lifeboat. A small pool in the chamber floor and a backup sprayer keep roots wet even if the main system fails completely.
Deep water culture (DWC) uses the same controller with a different mode, for people who want a gentler start.
Set it, check in, tell it what you see
The goal is a system you set up once, check on from your phone, and talk to like a grower. Type "lower leaves are yellowing and the mist seems weak", and it checks the readings, finds what backs that up, and suggests one small change, which you approve or skip.
This week's sprint
Sprint 0 is the high-pressure loop on the bench: pump, pressure tank, one solenoid, three nozzles and a pressure sensor. The test is simple. Does the pressure hold, is every mist burst the same size, and how fine is the mist? We'll post the results, the photos and the mess in the next lab notes.
Want to follow along? Join the waitlist and we'll send each build update as it lands.
