Greenhouse Environmental Control
Replace manual irrigation schedules with soil-moisture triggers, monitor PAR light across your canopy, and get instant alerts when weather events threaten your crop.
The Problem
Light variability across canopy
Without PAR sensors, you have no visibility into how light levels vary across the canopy or whether supplemental lighting is hitting targets.
Manual irrigation scheduling
Hand-triggering irrigation based on a fixed schedule wastes water and leads to over- or under-watering when weather changes.
Late detection of temperature swings
Nighttime drops or afternoon heat spikes can stress plants for hours before a grower notices during the next walkthrough.
Wind and weather events
High wind events or unexpected rain can cause structural damage or flooding, with no automated notification to the grower.
How LoopString Solves It
PAR light & environmental monitoring
Track photosynthetically active radiation alongside temperature and humidity to optimize your daily light integral.
Automated irrigation triggers
Soil moisture sensors drive irrigation rules — water runs when soil drops below threshold, not on a fixed clock.
Flexible scheduling
Layer time-based schedules on top of sensor triggers for complex irrigation and lighting programs.
Weather event alerts
Wind speed and temperature threshold alerts notify your team immediately when conditions approach plant-stress limits.
Hardware You'll Use
PAR light sensor
Photosynthetically active radiation for canopy light tracking
I²C / AnalogSoil moisture sensor
Capacitive soil moisture probes for irrigation automation
Analog / ADCSHT31
Air temperature and humidity for each greenhouse zone
I²CWind speed sensor
Anemometer for weather event detection and alerting
Pulse / Analog
Free tools for this work
VPD Chart
Read leaf VPD for any temp and humidity, coloured by growth stage. Printable.
VPD Calculator
Exact leaf VPD plus the control action to bring it into the band.
PPFD / DLI Calculator
Convert light intensity and photoperiod to daily light integral by crop.
Dew Point Calculator
Read the dew-point spread to catch condensation on glazing and crops.
Wet Bulb Calculator
Size pad-and-fan evaporative cooling against the wet-bulb depression.
Frequently asked questions
- Can LoopString automate a greenhouse — vents, fans, heating, and irrigation?
- Yes. The Pi drives vent, fan, heater, and irrigation relays from setpoints and schedules, using temperature, humidity, light, and soil-moisture inputs. Rules are built visually, no coding required.
- Does it use VPD or just temperature and humidity?
- Both. LoopString computes VPD from temperature and humidity so you can target the vapor-pressure deficit your crop wants, not just raw setpoints, and switch targets by growth stage.
- Can I check and adjust the greenhouse remotely?
- Yes — the dashboard is reachable from anywhere over Tailscale, so you can view live conditions and change setpoints from your phone while the control keeps running on-site.
Ready to automate your greenhouse?
Start free — no credit card required.