IoT Poultry Farm Environment Monitor

A poultry shed lives or dies on its air. When temperature climbs past a bird's comfort band, chickens eat less, pant, and stop gaining weight; when ammonia from the litter builds up, respiratory stress quietly follows and mortality rises. Farmers usually discover both problems the slow way — by walking the shed, by smell, by watching birds gasp. This project replaces guesswork with continuous sensing: a single ESP32 node carrying a DHT22 for temperature and humidity, an MQ-137 for ammonia, and a light sensor for photoperiod tracking, reporting to a shed dashboard that judges every reading against bird-comfort bands rather than raw numbers. Crossing a warning band raises a visible dashboard alert; crossing the heat-stress line fires the buzzer and switches the exhaust fan on automatically. It is livestock-welfare engineering first and an IoT data system second.

1. The ESP32 samples the DHT22 (temperature/humidity), MQ-137 (ammonia) and LDR light sensor on a fixed cycle; readings are filtered and converted to engineering units in firmware.
2. Firmware compares each reading against its comfort band (stored, configurable constants) — in-band, warning band, or alarm band — every cycle.
3. Entering a warning band flags WATCH on the dashboard and logs the event; entering the heat-stress or ammonia alarm band sounds the local buzzer and starts the exhaust fan.
4. Readings are pushed to the shed dashboard over Wi-Fi, where the gauge needles, the 24-hour comfort-band chart and the event log update live.
5. The light sensor accumulates on/off hours against the configured photoperiod schedule; deviations appear as schedule-fault entries.
6. Heartbeats carrying sensor status confirm the node is alive; a missed heartbeat raises a communication-fault entry instead of silently freezing the dashboard.

Tech stack:

• ESP32 development board
• DHT22 temperature-humidity sensor
• MQ-137 ammonia gas sensor module
• LDR light sensor module
• Relay module + 5 V exhaust fan
• Active buzzer (heat-stress alarm)
• Wi-Fi uplink to shed dashboard
• Comfort-band dashboard (HTML/CSS/JS single-file demo)
• Arduino IDE firmware

• [Comfort-band firmware logic] Temperature, humidity and ammonia are judged against configurable comfort bands (e.g. 18–24 °C, 50–70 %RH, <20 ppm NH3 as design defaults), with warning and alarm tiers so the dashboard shows WATCH before it shows ALARM.
• [Heat-stress alerting] Temperature breaching the alarm line fires a local buzzer and raises a heat-stress event with the exact reading and time — the demo shows how the alert chain looks end to end.
• [Automatic exhaust-fan control] A relay module drives the shed exhaust fan when temperature crosses the fan-on threshold, with hysteresis so the fan does not chatter around the setpoint.
• [Ammonia monitoring with MQ-137] The ammonia-specific SnO2 sensor tracks shed NH3 continuously; readings crossing the warn/alarm thresholds are logged with the action taken.
• [Photoperiod tracking] The light sensor records day/night hours against the configured lighting schedule (layers need consistent photoperiods), flagging deviations on the dashboard.
• [Live comfort-band dashboard] One screen shows all four gauges with band indicators, the 24-hour temperature curve drawn against the comfort band, the event log and control status.
• [Sensor health and heartbeat] The node reports sensor status and heartbeat periodically, so a disconnected DHT22 or an unheated MQ-137 reads as a fault, never as clean data.
• [Calibration and band-tuning guide] Procedures for MQ-137 burn-in, load-resistor tuning and adapting the comfort bands to the bird type (broiler vs layer, chick vs grower) are documented.

• Fully wired ESP32 sensor node (DHT22, MQ-137, LDR, relay, fan, buzzer, 5 V supply)
• Arduino firmware (sampling, comfort-band logic, fan control, buzzer alarm, Wi-Fi uplink, heartbeat)
• Comfort-band dashboard matching the demo: gauges, 24 h comfort-band chart, event log, control status
• Sensor calibration and comfort-band tuning procedure (MQ-137 burn-in, bird-type band tables)
• Shed mounting guide (node placement height, sensor exposure, fan positioning)
• Complete wiring diagram and schematic
• Project report PDF (background, poultry environment science, sensor theory, methodology, observations)
• PPT presentation for final review
• Viva Q&A preparation document (comfort bands, heat stress, MQ sensor principles, hysteresis, photoperiod, calibration)

• MQ-137 needs 24–48 h burn-in and periodic recalibration; ammonia readings are indicative comfort bands, not laboratory-grade measurements — the procedure is part of the deliverable.
• DHT22 humidity accuracy drifts at sustained high humidity (>90 %RH); readings at the extremes are approximate.
• Comfort bands are design defaults for general broiler/layer guidance — they must be adapted to the actual bird type and age, and the tuning guide explains how.
• The system warns and ventilates; it does not replace shed management practices (litter management, stocking density) that control ammonia at source.
• Wi-Fi must reach the shed; the local buzzer and fan work offline, but the dashboard does not log during an uplink outage.