Crop monitoring and controlling system is a project which is supposed to work on agriculture fields. The robot is controlled through mobile application build on MIT App inventor. The robot has reduced the human effort by working autonomously. The robot consist of multiple features. firstly it will give real tie readings of temperature, humidity and soil moisture sensors which will later be saved in form of google sheet to maintain the record of data. Secondly there is camera fitted on robot which will be giving live visualization. More over the main features and control of pests and fertilizer deployment. The pests spray will be fitted on robot, when the farmer will switch the button on on the customized mobile application the robot will move automatically and spray throughout the field. In fertilizer deployment when the ultrasonic sensor will detect plant it will deploy liquid fertilizer to specific plant so that fertilizer will not be wasted.

Precision Agronomy: Crop Monitoring & Control

This project scales basic sensor data into an autonomous, closed-loop industrial environment. It does not just alert the farmer; it acts as the farmer, mathematically tracking thousands of data points to orchestrate complex hydroponic or soil-based life support networks.

The Multi-Variable Control Matrix

Plants die quickly in extreme conditions. The code must balance conflicting metrics perfectly.

1. Atmospheric Heat (DHT22 / BME280): If ambientTemp > 35 (Celsius), the greenhouse is overheating. The Arduino fires an exhaust fan relay.
2. Soil Hydration (Capacitive Probes): If soilMoisture < 30%, the plant is dying of thirst. The Arduino fires a massive 12V diaphragm water pump relay.
3. The Conflict Engine: What if spraying water onto the dirt inadvertently raises the internal humidity above 90%, causing mold spores to explode?
   • The Interlock Protocol:

if (soilMoisture < 30 && ambientHumidity < 85) {
  runWaterPump(1000); // Only water if it won't ruin the air!
} else if (ambientHumidity > 85) {
  runExhaustFan(5000); // Vent the mold-causing air immediately!
}

Eliminating False Positives

A cheap analog soil sensor will give erratic spikes (saying it is perfectly dry when it is soaking wet) due to electrical noise.

• The system must utilize Data Averaging.
• The Arduino takes 50 readings of the soil over 10 seconds. It adds them together, divides by 50 to find the mean average, and throws out terrifying mathematical outliers before deciding to dump gallons of water into a greenhouse!

Farm-Grade Hardware Integration

• Arduino Mega or ESP32 (For massive I/O pins and Wi-Fi data logging).
• Capacitive Soil Moisture Sensors v1.2 (Absolutely mandatory. Resistance-based YL-69 probes will rot in a damp greenhouse in a week).
• DHT22 / BME280 Atmospheric sensors.
• Optically Isolated 4-Channel 5V Relay Boards.
• 12V Water Pumps, 12V Exhaust Fans, and dedicated Power Supplies.
• (Optional Upgrade: Integration of an LDR to measure sunlight intensity, automatically deploying a physical servo-driven shade-cloth over the greenhouse roof if the lux values go supercritical!)