Smart Seed Germination Chamber with Soil and Climate Monitoring

Germination fails silently. Seeds sown in a tray dry out between waterings, or sit too cold to sprout, and the student discovers the failure a week later when nothing emerges. Manual checking — a finger in the soil twice a day — misses the drying cycles that matter, and there is no record of what the tray actually experienced. This project instruments the germination tray: soil-moisture probes in the seed medium report how wet the root zone is, a DHT22 tracks the chamber's temperature and humidity, and a 16x2 LCD continuously shows the germination status with live readings. A low-power LED strip above the tray gives emerging seedlings light on a timed schedule, and the clear enclosure traps humidity while keeping the whole experiment visible. The build is honest college-prototype style — breadboard, jumper wires, handwritten labels — and every sensor reading is explainable in the viva.

1. Soil-moisture probes buried in the seed tray and a DHT22 in the chamber air report to the ESP32 on a timed sampling cycle.
2. Firmware converts the probe readings to moisture levels using the student's calibration and compares all three parameters against configured safe bands.
3. The LCD shows the germination status with live temperature and humidity; a band violation changes the status flag.
4. The LED grow-light strip switches on the configured schedule to support seedlings once they emerge.
5. The clear enclosure is opened only for watering; the status display tells the student when watering is actually needed.
6. All thresholds are firmware constants with documented defaults, retunable for different seed types.

Tech stack:

• ESP32 DevKit (Arduino/C++ firmware)
• DHT22 temperature/humidity sensor
• Soil-moisture probes
• 16x2 character LCD
• LED grow-light strip
• Transparent chamber enclosure

• [Soil moisture sensing] Probes in the seed tray report root-zone moisture so the student knows exactly when the medium is drying out, instead of guessing by touch.
• [Temperature and humidity monitoring] A DHT22 tracks chamber climate against germination-friendly bands, displayed live on the LCD.
• [Germination status display] The LCD shows a plain-language status (e.g. Germination OK) with current temperature and humidity readings.
• [Timed LED grow light] A low-power LED strip over the tray supports seedlings after emergence on a configurable light schedule.
• [Clear observation enclosure] The transparent chamber holds humidity in while letting the student watch germination without opening it.
• [Threshold flagging in firmware] Configurable bands flag when temperature, humidity or soil moisture leave the safe range.
• [Probe calibration procedure] A documented soil-probe calibration routine so readings are meaningful for the student's own medium.

• Working germination chamber prototype (ESP32, DHT22, soil probes, LCD, LED strip, enclosure, seed tray)
• Arduino firmware with thresholds and light scheduling
• Wiring diagram and connection list
• Soil-probe calibration procedure
• Project report PDF, PPT presentation and viva Q&A document

• Resistive soil probes corrode over weeks of wet use; readings are comparative, and the report documents the capacitive-probe upgrade as future scope.
• The chamber is a passive enclosure — it retains humidity but has no active heating or misting; climate bands are monitored, not forced.
• DHT22 accuracy is ±0.5 °C / ±2–5 %RH per its datasheet; readings are indicative.
• The LED strip is a low-power demo light, not a horticultural grow light with a specified spectrum.
• Germination results depend on seed viability and medium — the system monitors conditions, it cannot guarantee sprouting.