M5Stack Atomic Voice Base with Microphone and Speaker
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M5Stack Atomic Voice Base with Microphone and Speaker
M5Stack Atomic Voice Base with Microphone and Speaker is a compact voice recognition base designed for the M5 Atom series. This Atomic Voice Base adds a complete audio input and output path to a compatible Atom host, combining the ES8311 mono audio codec, a MEMS microphone, and the NS4150B Class-D amplifier with a built-in 1W 8Ω speaker.
Unlike an integrated Atom Echo style controller, this product is a base module without its own main SoC. It is built for projects that need full-duplex audio, I2S voice interaction, voice wake-up, speech playback, and compact smart home voice control. It is especially useful when paired with an AtomS3R host for Home Assistant, OpenAI voice assistant, and other embedded voice assistant workflows.

Features
- Built for the M5 Atom series, adding microphone and speaker capability through the Atom base interface.
- ES8311 mono audio codec with 24-bit resolution and 16KHz to 64KHz sampling support.
- MEMS microphone optimized for voice recognition and embedded audio input.
- NS4150B Class-D amplifier driving a built-in 1W @ 8Ω speaker.
- Full-duplex audio communication for simultaneous input and output.
- I2S-based audio path suitable for wake word, voice interaction, and playback workflows.
- Compact 24 × 24 mm footprint that matches the Atom family form factor.
- Official support materials for Arduino, UiFlow2, and ESP-IDF based development.
Specifications
| Specification | Parameter |
|---|---|
| Product Type | Atomic Voice Base for M5 Atom series |
| Audio Codec | ES8311, 24-bit resolution, I2S protocol |
| MEMS Microphone | MSM381A3729H9BPC, SNR ≥ 65 dB |
| Power Amplifier | NS4150B Class-D amplifier |
| Speaker | 2014 cavity speaker, 1W @ 8Ω |
| Sampling Rate | 16KHz to 64KHz |
| Standby Current | DC 3.3V / 3.36mA |
| Operating Current | DC 3.3V / 14.84mA |
| Operating Temperature | 0 to 40°C |
| Product Size | 24.0 × 24.0 × 14.1mm |
| Product Weight | 6.5g |
| Package Size | 85.0 × 65.5 × 15.0mm |
| Gross Weight | 12.5g |
Applications
Atomic Voice Base is a practical choice for embedded voice interaction, smart home voice control, custom voice assistant terminals, and compact M5Stack audio projects. M5Stack's own materials show it used with AtomS3R for Home Assistant voice assistant, OpenAI-based voice assistant, and XiaoZhi voice assistant workflows.
- Home Assistant voice assistant nodes with AtomS3R
- OpenAI voice assistant and embedded real-time voice interaction
- Wake-word and voice response projects for smart devices
- Interactive education projects based on the M5 Atom ecosystem
- Compact IoT audio control terminals with microphone and speaker

Related OpenELAB article: How to Build Your Own Personal Voice Assistant
Product List
- 1 × Atomic Voice Base
Other Content
PinMap
| Left Signal | Pin | Pin | Right Signal |
|---|---|---|---|
| 1 | 3V3 | ||
| SCL | 2 | 3 | DIN |
| SDA | 4 | 5 | LRCK |
| 5V | 6 | 7 | DOUT |
| GND | 8 | 9 | SCK |
Hardware reference

Practical note: this base is intended to be paired with an M5 Atom host. If you want an all-in-one voice development unit with the controller already onboard, see M5Stack ATOM Voice Smart Speaker Development Kit.
Resources
- Official M5Stack product documentation
- Atomic Voice Base schematic PDF
- ES8311 datasheet
- MEMS microphone datasheet
- NS4150B datasheet
- OpenAI Voice Assistant for AtomS3R + Atomic Voice Base
- Atomic Voice Base XiaoZhi Voice Assistant
- AtomS3R + Atomic Voice Base for Home Assistant
- Atomic Voice Base Arduino library
- Atomic Voice Base UiFlow2 documentation
- Open RealtimeAPI Embedded SDK
- Product introduction video
- OpenAI voice assistant demo video
FAQ
Does Atomic Voice Base include the main controller?
No. Atomic Voice Base is a base module for the M5 Atom series and does not include its own standalone host controller.
What is the difference between Atomic Voice Base and ATOM Voice / Atom Echo?
Atomic Voice Base provides the microphone, codec, amplifier, and speaker base, while ATOM Voice / Atom Echo is the integrated version with the controller already built in.
Can it be used for Home Assistant or OpenAI voice assistant projects?
Yes. M5Stack provides official tutorials for Home Assistant, OpenAI voice assistant, and other voice assistant workflows built around AtomS3R + Atomic Voice Base.
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2. Shipping Rates & Options
Shipping rates are calculated based on order value, destination, and available shipping methods. The final available options will be displayed at checkout.
2.1 Germany Domestic Shipping
| Shipping Method | Order Value | Cost | Est. Delivery |
|---|---|---|---|
| Deutsche Post | €0.00 - €50.00 | €4.95 | 2-4 Business Days |
| Deutsche Post | Over €50.00 | Free | 2-4 Business Days |
|
DHL Paket (Faster Delivery) |
€0.00 - €50.00 | €6.95 | 1-3 Business Days |
|
DHL Paket (Faster Delivery) |
€50.00 - €100.00 | €2.00 | 1-3 Business Days |
|
DHL Paket (Faster Delivery) |
Over €100.00 | Free | 1-3 Business Days |
2.2 Selected EU Countries / Regions
Available EU shipping destinations are shown at checkout based on your shipping address. For orders shipped to selected EU countries or regions outside Germany, we use FedEx Regional Economy.
| Shipping Method | Order Value | Cost | Est. Delivery |
|---|---|---|---|
| FedEx Regional Economy | €0.00 - €100.00 | €7.95 | 3-5 Business Days |
| FedEx Regional Economy | Over €100.00 | Free | 3-5 Business Days |
EU orders may be fulfilled from our Munich warehouse or, when applicable, from our Shenzhen warehouse depending on inventory availability. For EU member states, OpenELAB covers applicable import duties and taxes under DDP service where required.
2.3 United States
| Region | Shipping Method | Order Value | Cost | Est. Delivery |
|---|---|---|---|---|
|
Continental U.S. (50 States) |
USPS Ground Advantage | €0.00 - €45.00 | €4.95 | 3-7 Business Days |
| USPS Ground Advantage | Over €45.00 | Free | 3-7 Business Days | |
| USPS Priority Mail | €0.00 - €45.00 | €16.95 | 1-4 Business Days | |
| USPS Priority Mail | Over €45.00 | €14.95 | 1-4 Business Days | |
|
Non-Continental U.S. (AK, HI, PR, etc.) |
USPS Ground Advantage | €0.00 - €60.00 | €6.95 | 5-9 Business Days |
| USPS Ground Advantage | Over €60.00 | Free | 5-9 Business Days |
Non-Continental U.S. regions include Alaska, American Samoa, Guam, Hawaii, the Marshall Islands, the Northern Mariana Islands, Palau, Puerto Rico, the U.S. Virgin Islands, and U.S. Armed Forces addresses.
2.4 International Destinations Outside the EU
For selected international destinations outside the EU, including Switzerland, the United Kingdom, and Norway, shipping rates are as follows:
| Order Amount | Shipping Cost |
|---|---|
| €0.00 - €300.00 | €19.95 |
| Over €300.00 | Free |
For non-EU destinations, import duties, taxes, and customs fees may be charged by the destination country and are the responsibility of the recipient.
3. Warehouses & Fulfillment
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3.1 Munich Warehouse
For products stored in our Munich warehouse, we use Deutsche Post or DHL Paket for domestic deliveries within Germany. For selected EU destinations outside Germany, we use FedEx Regional Economy.
3.2 Arlington Warehouse
For products stored in our Arlington warehouse, we use USPS or UPS for deliveries within the United States.
3.3 Shenzhen Warehouse
For pre-order items or products fulfilled directly from our Shenzhen warehouse, we arrange reliable international shipping based on destination and inventory status. For EU member states, OpenELAB covers applicable import duties and taxes under DDP service where required.
4. Inventory, Pre-orders & Split Shipments
- Inventory Status: Please check the product page for real-time stock information. If an item is out of stock in our local warehouses, it may be marked as “Pre-order”.
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- Split Shipments: If your order contains both in-stock and pre-order items, we may ship them separately. No additional shipping fee will be charged for split shipments caused by our fulfillment arrangement.
5. Customs, Taxes & Delivery Issues
5.1 Customs and Taxes
For EU Member States:
Whether shipped from Germany or China, OpenELAB covers applicable import duties and taxes under DDP service where required. Customers in EU member states should not be charged additional import duties or VAT upon delivery.
For destinations outside the European Union, such as Switzerland, Norway, and the United Kingdom, import duties, taxes, and customs fees may be charged by local authorities upon delivery. These fees are the responsibility of the recipient.
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If your parcel is delayed, lost, returned to sender, or the tracking information has not updated for an unusual period of time, please contact us at info@openelab.io. We will assist you in checking the shipment status with the courier.
5.3 Incorrect Address or Failed Delivery
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6. VAT
For orders within the EU, VAT is collected at checkout according to the applicable destination rules. No additional VAT should be collected upon delivery for EU member state orders covered under our DDP shipping arrangement.









