Voice Command Recorder Pro Kit with ESP32
Voice Command Recorder Pro Kit – Dual Mic ESP32 with Real-Time NLMS Echo Cancellation
Every part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.
Voice interfaces fail when the device’s own speaker output drowns out the user’s command. This kit turns that problem into a hands-on learning project: you’ll build a voice recording system that actively subtracts the speaker signal from the microphone input using a Normalized Least Mean Squares (NLMS) adaptive filter running on an ESP32. The result is clean, far-field voice capture ready for wake-word detection or cloud ASR—ideal for prototyping smart speakers, voice-controlled appliances, or acoustic research rigs.
What You'll Build
You’ll assemble a dual INMP441 microphone array on a custom PCB, wire it to the ESP32 I2S bus, and deploy an NLMS algorithm that continuously adapts to cancel the echo from a PAM8403 speaker. The processed audio stream can be routed over Wi-Fi or logged for analysis. By the end you’ll have a self-contained hardware module that records voice commands clearly even while playing loud audio—a core building block for any always-listening device.
What You'll Learn
- Implement the Normalized Least Mean Squares (NLMS) adaptive filter in C on ESP32 for real-time acoustic echo cancellation.
- Configure dual INMP441 I2S microphones for synchronized sampling and interleaved audio streaming.
- Drive a PAM8403 amplifier and speaker while capturing clean microphone input without feedback loops.
- Debug real-time DSP pipelines using serial plots and audio analysis tools to fine-tune filter parameters.
Kit Contents
| Component | Quantity |
|---|---|
| ESP32 Dev Board | 1 |
| INMP441 I2S Mic | 2 |
| MCP4728 DAC | 1 |
| PAM8403 Amp | 1 |
| 3W 8Ω Speaker | 1 |
| 4.7kΩ Resistors | 5 |
| 100nF Caps | 10 |
| PCB Prototype Board | 2 |
| 3.5mm TRS Jack | 2 |
| Enclosure Box | 1 |
| 5V 2A 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 targets DSP engineers and advanced hobbyists building reliable voice capture for embedded systems. It’s an ideal capstone for B.Tech ECE/EEE final-year projects focusing on adaptive filters, a research tool for M.Tech students at IITs, NITs, and IISc prototyping real-time AEC, or a rapid development base for hardware startups creating smart speaker products. Even experienced makers tackling the hardware track of Smart India Hackathon will find a ready‑to‑go far‑field voice front end inside.
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 to open the AI companion that knows the voice recorder project inside out—wiring, code, and filter tuning. If you need human help, send a WhatsApp message to our support number, and an engineer will respond within 24 hours.
Can I use this kit to build a smart speaker with voice assistants like Alexa?
Absolutely. The NLMS echo cancellation ensures the dual microphones pick up voice commands cleanly even while the speaker plays music or responses. You can integrate the processed audio with Alexa Voice Service or a custom ESP32 wake‑word engine to create a fully functional smart speaker.
Does the kit include pre‑trained models for the NLMS filter?
The kit provides working ESP‑IDF code that implements the NLMS adaptive filter, along with a Python simulation script to adjust step size and filter length for your room acoustics. You can run the simulation on a PC before flashing the ESP32.
Is soldering required for assembly?
Yes, you’ll solder the INMP441 mics, DAC, amplifier, and passive components onto the prototype boards. A 25 W soldering iron and lead‑free solder are included, making this a zero‑extra‑purchase assembly experience.
Voice — Dual INMP441 I2S mics on ESP32 implement NLMS adaptive filter to cancel echo from speaker output in real time.
What's in this kit
- ESP32 Dev Board
- INMP441 I2S Mic x2
- MCP4728 DAC
- PAM8403 Amp
- 3W 8Ω Speaker
- 4.7kΩ Resistors x5
- 100nF Caps x10
- PCB Prototype Board x2
- 3.5mm TRS Jack x2
- Enclosure Box
- 5V 2A PSU
- Soldering Iron
- Solder Wire
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