---
id: edge-lora-sprinkler
area: edge
level: 3
title: "Artefact — LoRa irrigation under solar power"
claim: "A solar-powered controller that sleeps · wakes on radio · and drives a solenoid — with the first version polling over a message queue instead."
confidence: running
period: "2020–"
tech: [ESP32, LoRa, LiFePO, Solenoid, Home Assistant, RabbitMQ]
metrics: [{label: "major revisions", value: 2}]
artefacts: []
public: true
last_verified: 2026-10-26
tags: [edge, lora, solar, irrigation, artefact]
---

# Artefact — LoRa irrigation under solar power

**Status: stub.** The bill of materials and the wake-on-radio change land in Phase 7.

## What the artefact is

The build: solar panel, charge controller, LiFePO battery, ESP32, LoRa module, relay and solenoid valve. Version one woke on a schedule and polled through a message queue to learn whether it should run. Version two is better: a LoRa packet can wake the ESP32 from deep sleep and switch the valve directly, so on-time is short and the battery is not spent asking whether there is work.

## What it proves

Iteration on a real constraint. The first version worked; the second version was designed around the power cost of asking, which is the kind of decision you only make if you are watching the battery.

## Limits stated on the page

Watering is partly scheduled and partly a person. The routine lives in the automation layer and the voice assistant can trigger it, but the garden is not fully automatic and the page does not pretend otherwise.

## When it is delivered

Phase 7. Source: evidence notes section 1.