Soil pH Field Tester Kit with Raspberry Pi 4 + Relay
Build an Offline Voice-Driven Soil pH Field Tester with Raspberry Pi 4
Every part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.
Walk into a field, speak a wake word, and your device starts measuring soil pH – all without a cloud connection. This kit puts an entire voice recognition and automation stack on a Raspberry Pi 4 running Rhasspy. You’ll train a custom wake word, map spoken commands to intent recognition, and fire 5V relays that can drive pumps, solenoid valves, or alarms. No internet, no privacy concerns, just a rugged, standalone soil analysis sidekick built entirely by you.
What You'll Build
A portable, voice-activated soil pH monitoring system that you can deploy in open fields or greenhouses. Once assembled, the unit listens for your chosen wake word, then interprets commands like “read pH”, “start irrigation”, or “log data”. It processes everything on-device using the Pi 4’s quad-core processor. The PAM8403 amplifier and 3W speaker provide clear feedback, while the dual relay modules let you control external hardware such as peristaltic pumps for nutrient dosing. You’ll integrate a standard analog pH probe (like the popular E-201C, not included) via an ADC, completing a fully functional soil tester that works where connectivity ends.
What You'll Learn
- Train and deploy a custom wake word on a Raspberry Pi 4 using Rhasspy’s local speech engine.
- Design an offline voice-controlled automation system with intent recognition and GPIO-driven relay outputs.
- Interface an analog soil pH sensor with the Pi’s GPIO through an ADC (sensor not included).
- Solder and assemble a compact audio input/output stage using a USB microphone, amplifier, and speaker.
Kit Contents
| Component | Quantity |
|---|---|
| Raspberry Pi 4 Model B 4GB | 1 |
| USB Microphone | 1 |
| PAM8403 Amp | 1 |
| 3W 8Ω Speaker | 1 |
| 5V Relay Module | 2 |
| 1N4007 Diode | 5 |
| M-F Wires | 15 |
| MicroSD Card 32GB | 1 |
| USB-C PSU | 1 |
| Soldering Iron | 1 |
| Solder Wire | 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
This kit speaks directly to B.Tech ECE and EEE students tackling agritech or precision farming projects. It’s a strong foundation for Smart India Hackathon prototypes where a completely offline, voice-controlled soil analyser gives a competitive edge. ATL Tinkering Lab mentors and university innovation cells at IITs, NITs, VIT, and BITS will find the ready-made hardware stack ideal for teaching edge voice AI. If your final-year project demands a field-deployable IoT device that understands spoken commands, you’ll skip months of integration guesswork.
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?
Scan the QR code on the box to open your AI build companion. It understands every component and step in this kit. If you need a human touch, reply on WhatsApp and our engineers will help you through the snag.
Do I need to buy a separate soil pH sensor?
Yes, the kit does not include an analog pH probe to keep you flexible. We recommend the commonly available E-201C electrode with a simple ADC module, which connects easily to the Pi’s GPIO. The AI companion will guide you through the wiring and calibration.
Can I reuse this platform for other farm automation tasks?
Absolutely. Once you’ve built the voice-controlled soil tester, the same relay outputs and Rhasspy setup can be repurposed for temperature-driven fan control, automatic irrigation scheduling, or even a voice-activated scarecrow. The relay modules and audio stack are generic and highly reusable.
Is voice processing completely offline, and will it work without any internet?
Yes. Rhasspy runs all speech recognition and intent parsing on the Raspberry Pi itself. No data ever leaves the device. It works reliably in remote fields with zero connectivity, as long as you have the kit’s USB-C PSU or a battery bank.
Soil Analysis — Pi 4 runs Rhasspy fully offline. Custom wake word, intent recognition and GPIO relay control. No cloud.
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