Cannabis Cultivation Automation
Edge-PID per-room climate control through clone → veg → flower → dry → cure, with recipe automation that runs the stage transitions and audit-grade environmental records for state seed-to-sale compliance.
Cultivating non-cannabis (mushrooms, microgreens, lettuce)? See the generic grow rooms page. Evaluating a TrolMaster build? See the comparison.
The Problem
A bad day in flower kills the harvest
Cannabis is unforgiving in flower — wrong VPD pushes mildew, wrong RH at week 6 invites bud rot, a stuck dehumidifier on a weekend ruins a month of work.
Per-stage targets, per-room differences
Clone, veg, flower, dry, and cure each have distinct T/RH/CO₂/VPD profiles. Hand-tuning every room every phase is hours per week — and assumes the operator notices the drift.
No remote visibility for multi-room facilities
A typical commercial grow has 2–10+ flower rooms plus a veg room, dry room, and cure rooms. No single dashboard means no one sees the slow drift until product quality suffers.
State cannabis programs expect records
METRC, BioTrack, and other state seed-to-sale systems track plants. Environmental records — temperature, humidity, light cycles — are increasingly required at inspection. Paper logs are an audit risk.
How LoopString Solves It
On-edge PID + VPD control per room
Pi-side PID loops drive AC, dehumidifier, humidifier, exhaust, and CO₂ valves for each room independently. VPD is computed locally so targets follow the canopy state, not just the wall thermostat.
Multi-room dashboard with stage-aware targets
See every room — veg, every flower room, dry, cure — on one screen. Sparkline trends per signal. Recipe automation drives the stage transitions (veg → early flower → late flower → dry → cure).
Threshold alerts before product is at risk
Configure narrow alert windows per room per stage. Anomaly detection on rolling baseline catches failing AC compressors, stuck dehumidifiers, and CO₂ regulator drift before they hit the canopy.
Audit-grade environmental records
Every reading logged with a tamper-resistant timestamp. Per-room daily, weekly, and full-cycle PDF reports for inspections, internal QA, and lot-level traceability.
Built for these cannabis operators
Licensed commercial cultivators
Multi-room flower facilities running METRC / BioTrack / state seed-to-sale; need audit-grade environmental records alongside plant tracking.
Craft + small-batch cultivators
1–3 room operations that need professional-grade automation without integrator-quote pricing.
Sungrown + greenhouse cannabis
Greenhouse cannabis needs supplemental humidity + CO₂ + vent control tuned to outdoor light + temperature swings.
Tissue culture + mother rooms
Clone/mother rooms with tighter T/RH windows + sterile-area procedures need their own controlled environment + records.
Drying + curing rooms
Post-harvest drying (60 °F / 60% RH) → cure (jars or bins at 65 °F / 62% RH for weeks) — continuous logging makes terpene preservation defensible.
Multi-location MSOs
Multi-state operators with facilities in different jurisdictions need a single dashboard + RBAC + state-by-state report exports.
Hardware You'll Use
SHT31
Combined T + RH per room — used for VPD calc
I²CMH-Z19B
NDIR CO₂ sensor (1500 ppm target in flower)
UARTDS18B20
Canopy-level temperature probes
1-WireRelay module
AC, dehumidifier, humidifier, exhaust, CO₂ valve control
GPIO
On compliance scope
LoopString provides environmental records (temperature, humidity, CO₂, light, VPD) and automation logs. It does not integrate with METRC, BioTrack, or Confident Cannabis directly — those systems track plant inventory and seed-to-sale. The two layers complement each other: METRC tracks the plant; LoopString tracks the environment the plant grew in. Most state inspectors accept LoopString PDF exports as supporting environmental documentation alongside the METRC trail.
Ready to take the canopy off the wall thermostat?
Start free — no credit card required.