Precision Fertiliser Spreader Controller Kit with ESP32 + LED
Precision Fertiliser Spreader Controller Kit with ESP32 & GPS — Master Variable-Rate Agriculture
Every part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.
Achieve site-specific fertiliser application with this open-source controller. Instead of blanket spreading, you’ll build a device that reads GPS coordinates and a soil electrical conductivity (EC) map from a microSD card, then modulates a PWM-driven relay to vary the spreader valve opening in real time. This eliminates over-application on high-fertility zones and under-application on poor soils, cutting input costs and environmental runoff.
What You'll Build
You’ll assemble and program an ESP32-based controller that mounts inside a waterproof enclosure. It interfaces with a GPS module to track field position, a TDS EC probe to sense soil conductivity on-the-go, and an RTC for time-stamped logging. The device compares the current GPS fix against a pre-loaded prescription map (CSV on microSD), decides the target application rate, and outputs a PWM signal to the IRF540N MOSFET—which in turn drives a 12V solenoid valve on your existing fertiliser spreader. The OLED displays real-time coordinates, target rate, and system status.
What You'll Learn
- Integrate GPS data (NMEA sentences) and parse coordinates with an ESP32
- Calibrate a TDS/EC meter and convert readings to soil electrical conductivity values
- Read and write CSV prescription files from microSD using SPI
- Generate variable-frequency PWM signals on an ESP32 GPIO to control a high-current MOSFET relay
Kit Contents
| Component | Quantity |
|---|---|
| ESP32 Dev Board | 1 |
| NEO-6M GPS Module | 1 |
| TDS EC Meter | 1 |
| DS3231 RTC Module | 1 |
| MicroSD Card Module | 1 |
| IRF540N MOSFET | 1 |
| LM2596 Buck Converter | 1 |
| 0.96 inch OLED Display | 1 |
| 100nF Ceramic Capacitors | 10 |
| 4.7kΩ Resistors | 5 |
| PCB Prototype Board | 2 |
| Waterproof Enclosure | 1 |
| 12V Power Supply Unit | 1 |
| Soldering Iron (25W) | 1 |
| Solder Wire (50g) | 1 |
Why Buy This Kit Instead of Sourcing Parts Separately
| Factor | Sourcing Separately | Compoden Kit |
|---|---|---|
| Compatibility checks | You verify every part | Pre-tested as a system |
| Build support | Forums and scattered tutorials | AI companion trained on this exact project |
| Time to first working build | Days of debugging | Hours, with step-by-step guidance |
| Shipping coordination | Multiple sellers, multiple delays | One shipment from Bengaluru in 3-5 days |
Who This Kit Is For
Agricultural engineers and B.Tech Agri/Automation students working on Smart India Hackathon challenges or final-year projects in precision farming. It also suits farm owners with an interest in IoT who want to retrofit a tractor-mounted spreader. If you’ve coded in Arduino IDE and handled basic soldering, you’re ready to tackle this advanced build.
Built and Backed by Compoden
Every Compoden kit ships with an AI build companion trained on this exact project — accessible via a QR code on the box, with WhatsApp and email backup. We've spent 10 years building projects for makers, schools, and institutions across India. If a part fails because of a manufacturing defect, replace it free within 7 days.
What if I get stuck during the build?
The AI companion diagnoses issues step-by-step, and you can reach our support team on WhatsApp with photos of your wiring.
Will this work with a 24V tractor electrical system?
The included LM2596 buck converter accepts up to 35V, so you can directly tap into a 24V battery; set its output to 5V for the ESP32 and logic circuits.
Can I use this kit without a spreader machine?
Yes, the MOSFET output can drive any solenoid valve up to 5A. You can test with a 12V solenoid and water flow to simulate fertiliser application.
Does the prescription map need a specific format?
We provide a sample CSV template with latitude, longitude, and target rate columns. Your own map can be generated from soil testing data.
GPS and soil EC map guide variable rate spreader relay opening via PWM to match pre-loaded prescription map.
What's in this kit
Choose your assembly option:
- Soldering Kit — 25W soldering iron, 60/40 solder wire, flux, and small perfboard for permanent assembly.
- Breadboard Combo — 800-point full-size breadboard with 65-piece jumper wire pack for solderless prototyping.
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Shipping Information
- Prepaid Orders: ₹75 for orders up to ₹999, FREE shipping above ₹999
- COD Orders: ₹125 shipping + ₹50 COD fee = ₹175 total
- Delivery Timeline: Dispatch in 1-2 days, delivery in 2-7 days depending on location
Returns & Warranty
- 7-Day Return: Manufacturing defects only (approval required)
- Warranty: 7 days from delivery
- Non-Returnable: Batteries, consumables, cut wires, clearance items