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AtomU ESP32 Development Kit with USB-A

by M5Stack

ATOM U is a compact low-power consumption speech recognition IoT development kit.

It uses an ESP32 chipset, equipped with 2 low-power Xtensa 32-bit LX6 microprocessors with the main frequency of up to 240MHz. Built-in USB-A interface, IR emitter, programmable RGB LED. Plug-and-play, easy to upload and download programs. Integrated Wi-Fi and Bluetooth modes and digital microphone SPM1423(I2S) for the clear sound record. suitable for HMI, Speech-to-Text (STT).


ATOM U supports UIFlow graphical programming platform, scripting-free, cloud push; Fully compatible with Arduino, MicroPython, ESP32-IDF, and other mainstream development platforms, to quickly build various applications.


ATOM U contains a USB-A port for programming/power supply, IR emitter, programmable RGB LED x1, button x1; Finely tuned RF circuit, providing stable and reliable wireless communication.


ATOM U is easy access to M5Stack's hardware and software system


  • ESP32-PICO-D4 (2.4GHz Wi-Fi and Bluetooth dual mode)
  • Integrated programmable RGB LED and button
  • Compact design
  • Built-in IR emitter
  • Expandable pinout and GROVE port
  • Development platform:


  • IoT controller
  • Voice recording, Speech-to-Text services

Driver Installation

Connect the device to the PC, open the device manager to install FTDI driver for the device. Take the win10 environment as an example, download the driver file that matches the operating system, unzip it, and install it through the device manager. (Note: In some system environments, the driver needs to be installed twice for the driver to take effect. The unrecognized device name is usually M5Stack or USB Serial. Windows recommends using the driver file to install directly in the device manager (custom Update), the executable file installation method may not work properly). Click here to download FTDI driver


Specifications Parameters
ESP32-PICO-D4 240MHz dual core, 600 DMIPS, 520KB SRAM, 2.4G Wi-Fi, dual mode Bluetooth
Microphone SPM1423
Microphone sensitivity 94dB SPL@1KHz Typical value: -22dBFS
Microphone signal-to-noise ratio 94dB SPL@1KHz, A-weighted Typical value: 61.4dB
Standby working current 40.4mA
Support input sound frequency 100Hz ~ 10KHz
Support PDM clock frequency 1.0 ~ 3.25MHz
Net weight 8.4g
Gross weight 10.6g
Product size 52 x 20 x 10mm
Packing size 68 x 21 x 11mm


  • UIFlow
    • This tutorial will show you how to control ATOM U devices through the UIFlow graphical programming platform
  • Arduino IDE
    • This tutorial will show you how to program and control ATOM U devices through Arduino IDE
  • Micropython
    • This tutorial will show you how to control ATOM U devices through Micropython programming
  • Datasheet