Soil pH Field Tester Kit v2
Soil pH Tester Kit v2: Voice-Controlled Pi 5 Soil Analysis
Every part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.
Build a Raspberry Pi 5 field unit that listens to your voice commands and controls relays for soil testing, even without an internet connection. This advanced project combines offline speech recognition with Vosk, custom wake word training, and GPIO-triggered relay outputs, so you can keep your hands free while analyzing soil samples in the field.
What You'll Build
Assemble a compact, battery-compatible unit with a USB microphone, amplifier, speaker, and two 5V relay channels. The Pi 5 runs a Vosk model that wakes on your custom phrase and activates relays on spoken commands — perfect for automating soil sample handling, pump switching, or probe triggering during field surveys.
What You'll Learn
- Offline speech recognition using Vosk on Raspberry Pi 5 (ARM64), replacing cloud dependencies with local processing
- Interfacing GPIO pins with relay modules, including flyback diode protection with 1N4007 diodes and transistor switching
- Training and deploying custom wake word models without any cloud service, enabling hands-free trigger in noisy outdoor environments
- Soldering through-hole components and assembling a robust field-ready enclosure powered by a standard USB‑C supply
Kit Contents
| Component | Quantity |
|---|---|
| Raspberry Pi 5 4GB | 1 |
| USB Microphone | 1 |
| PAM8403 Amp | 1 |
| 3W 8Ω Speaker | 1 |
| 5V Relay Module | 2 |
| 1N4007 Diode | 5 |
| 10kΩ Resistors | 5 |
| M-F Wires | 20 |
| 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 suits engineering students (B.Tech ECE/EEE) designing agri‑tech projects, Smart India Hackathon teams building voice‑controlled IoT for soil analysis, and final‑year students at NIT, VIT, or BITS Pilani who need a ready‑to‑assemble system for their thesis. It is also appropriate for CBSE Class 12 students with prior Raspberry Pi experience who want to explore offline AI in agriculture.
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?
Open the AI companion via the QR code; it has step‑by‑step guidance for this exact kit. If you need a human, reach our support on WhatsApp for help with wiring or code.
Can I train my own wake word instead of the default one?
Yes, the AI companion walks you through recording samples and adapting the Vosk model. You can switch wake words for different field scenarios.
Do I need an internet connection for voice recognition?
No, Vosk runs completely offline. The Pi 5 processes speech on‑device, so you can use the tester in remote fields without connectivity.
How can I connect this to a soil pH sensor or probe?
The two relay outputs can switch external circuits like solenoid valves or signal a commercial pH meter. The AI companion includes wiring diagrams for adding an analog pH sensor via an MCP3008 ADC (not included).
Soil Analysis — Pi 5 runs Vosk offline speech recognition with custom wake word. Triggers GPIO relays on voice commands.
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