A sketch is the small program that runs on a sensor's chip and makes it do its job: read the air, the soil, the water, and push the number somewhere you can keep it. These are the engines under the solutions. One sketch can power several: the same listener that watches a cooler watches a greenhouse zone, because only the sensor and the purpose change. Came here with a need rather than for code? Start at What do you want to know? instead; every solution there hands you its sketch in context.
The library.
The live sketches flash from the browser today. The source releases are complete, openly-licensed code you build and flash yourself: no image yet, but the whole project downloads and compiles as-is. The rest are the plan, arriving as they’re written with the collective. Everything here is openly licensed: copy it, change it, own it. The library is also on GitHub, filling out sketch by sketch as each one is reviewed.
BLE Sensor Listener powers: Cold-Chain Monitor · Greenhouse Monitor
SHT-30 Temperature & Humidity Node powers: Greenhouse Monitor
DS18B20 Temperature Node powers: Cold-Chain Monitor
Source releases, build & flash them yourself, each lands a whole class of sensor in data you own:
Planned, in rough order:
- Soil-Moisture Node, A capacitive soil probe for watering decisions.
- 915 MHz RF Listener, Hear the homestead radio band: cheap weather stations, soil probes and rain gauges already broadcasting over your property.
- LoRa Field Node, A sensor miles from the house, on a battery, with no Wi-Fi anywhere near it.
- LoRa Bridge, The far-field twin of the BLE Listener: hears distant field nodes, lands their readings in a place you own.
- Rule-Driven Relay, Control-side, a different conversation: switching things is not monitoring, and it lives with Control when it lands.
What a sketch gives you.
Every sketch page here follows the same six parts: the same Collect·Have·Use bones as the rest of the site, for firmware:
- What it does: the sensor, the board, and the need it meets, with the honest appropriate-tech sizing.
- Parts and wiring: a bill of materials with prices and a wiring diagram.
- The sketch: the actual code, ready to copy and flash, openly licensed.
- The push: how it gets the reading to an endpoint (a webhook or MQTT), with the settings to fill in. See Connectivity.
- What you get (the data it produces, and what reads it: a dashboard, an alert, the matching stack).
- Notes: calibration, failure modes, and the gotchas worth knowing before you trust it.
How to use one.
When a sketch lands, using it is the same four steps every time: gather the parts from its bill of materials, wire it per the diagram, copy the sketch onto the board (the page walks you through the free tools), and fill in your endpoint settings so the reading has somewhere to go. From there it is yours: change it, extend it, share what you learn. If you have built something worth passing on, the collective would love to add it; reach us through the Contact page.