Sipling

Sipling is a self-watering system I designed, 3D printed and built around an ESP32. The readings on this page are live from a Philodendron in my home, which it has been looking after on its own since September 24.

What it does

• Waters on its own. It checks the soil and waters only when it drops below the level you set, so the plant is never drowned or forgotten.
• Learns the plant. It learns how fast the soil dries and how much each watering really adds, and adjusts the dose to match. It also checks whether the plant gets the light its kind wants.
• Can't flood a plant. Several limits keep it safe: a maximum pump run, a daily cap, a minimum time between waterings, and a check that the soil actually got wetter afterwards.
• Watches the whole environment. Soil moisture, temperature, humidity, light (lux and daily light) and the water tank level.
• Works from anywhere. The phone app shows everything live, sends alerts, and lets you water by hand or change settings.

New: the Sipling iPhone app (public beta)

Sipling now has its own native iPhone app: pair your waterer, see live soil moisture, the tank level and your plant's mood, get alerts when it needs you, and water by hand. It's free to try through Apple's TestFlight. Get the Sipling app

New: a wireless sensor pod (prototype)

The sensors no longer have to be wired to the waterer. A small pod sits in the pot and sends soil moisture, light, temperature and humidity to the waterer over ESP-NOW, a direct radio link that needs no Wi-Fi setup.

• Setup without typing. Hold a new pod next to the waterer and the app walks you through naming it, calibrating its probe and choosing its job.
• No sensor wires. The finished unit uses the pod alone: the only thing running into the pot is the water line from the pump. While I prototype, the pod runs alongside the old wired sensors so I can compare the two side by side.
• Can't be faked. Every reading is signed, so nothing else can feed the waterer false soil readings.
• Updates itself. New pod firmware travels over the air, through the waterer.

The first pod is running on my test unit now, and I've designed a 3D-printed case for it. Next up: keeping its air sensor clear of the board's own heat, and a battery-powered version.

How it's built

• ESP32-S3 brain in a custom 3D-printed housing and reservoir, with the pump. The sensor pod runs on an ESP32-C3 board.
• Private by design. The unit only ever reaches out (no open ports on my home network) and reports every 10 minutes to a small cloud service, which is what the app and this page read.
• Signed updates. The waterer and its pods update over the air, and only accept firmware signed by me.
• Read-only demo. “Open the full interactive demo” runs the real app in demo mode: press water now, change the threshold, pick a plant. Nothing you do reaches the real plant.

I'm testing it on real plants now. Want one, or have questions? Send me a message.