M5Stack-ATOM

Development Board

Code name: M5Stack_ATOM

ESP32 M5STACK

M5Stack-ATOM is a development board based on the ESP32 microcontroller using XTENSA architecture.

This board features a maximum CPU frequency of 240 MHz and 4MB flash memory.

About M5Stack-ATOM

Ultra-compact ESP32 board with RGB LED and button - ideal for simple wireless triggers and automation nodes.

Technical Specifications

Complete technical specification details for M5Stack-ATOM

Connectivity

WiFi 802.11 b/g/n (2.4 GHz)

Bluetooth 4.2

BLE 4.2

Microcontroller

Model esp32

Clock Speed 240 MHz

Flash Size 4MB

Architecture xtensa

✨ Features & Pins

Digital IO 40

Analog Input 16

PWM 14

Interrupts 16

Download Full Datasheet

Quick Setup

Copy-paste configs for M5Stack-ATOM - auto‑generated from this board's exact hardware specs.

ESP32 240 MHz 4MB DIO Xtensa

In Arduino IDE 2 select M5stack Atom from the esp32 by Espressif package. In PlatformIO use board = esp32dev. ESP32 · 240 MHz · 4MB · DIO.

Tools menu settings

Board (select in Arduino IDE) M5stack Atom

CPU Frequency 240 MHz

Flash Size 4MB

Flash Mode DIO

Upload Speed 921600

Architecture Xtensa

In Arduino IDE 2, open Boards Manager, search "esp32" by Espressif and install it. Then go to Tools → Board and select "M5stack Atom" for the M5Stack-ATOM.

platformio.ini


[env:m5stack-atom]
platform  = espressif32
board     = esp32dev
framework = arduino

; Exact hardware config for M5Stack-ATOM
board_build.mcu        = esp32
board_build.f_cpu      = 240000000L
board_build.flash_size = 4MB
board_build.flash_mode = dio
board_upload.flash_size = 4MB

The board value is a close generic match - check PlatformIO board registry for an exact fit.

esp32: block (YAML)


esp32:
  board: esp32dev
  framework:
    type: arduino   # or "esp-idf"

# M5Stack-ATOM - 240 MHz ESP32
# Flash: 4MB | USB: N/A

Paste into your device's .yaml. See ESPHome ESP32 docs for full options.

esptool.py - flash command


esptool.py \
  --chip esp32 \
  --baud 921600 \
  write_flash \
    --flash_mode dio \
    --flash_size 4MB \
    0x1000 bootloader.bin \
    0x8000    partitions.bin \
    0xe000    boot_app0.bin \
    0x10000   firmware.bin

Install: pip install esptool - replace firmware.bin with your binary - bootloader at 0x1000

M5Stack-ATOM Pinout Diagram

Complete pin reference for M5Stack-ATOM

Useful Links

Datasheets and resources for M5Stack-ATOM

Board Datasheet

Technical specifications

ESP32 Datasheet

Microcontroller reference

Pin Mappings

Complete pinout and GPIO mapping for M5Stack-ATOM

Digital I/O Pins

Interrupt Pins

Analog Inputs

PWM Pins

Pin	PWM	Other
0		G0
1	PWM	TX
3	PWM	RX
9	PWM	G9
10	PWM	G10
12	PWM	G12
19	PWM	G19 SS
21	PWM	G21
22	PWM	G22 SCK
23	PWM	G23 MISO
25	PWM	G25 DAC1
26	PWM	RXD2 SDA G26 DAC2
27	PWM	G27
32	PWM	TXD2 SCL G32
33	PWM	G33 MOSI
35		ADC1
36		G36 ADC2
37		G37
39		G39

Legend

A0 Analog input

T0 Touch sensor

PWM PWM capable

RX/TX Serial pins

LED Built-in LED

# Pin number

Default Tools & Configuration

Build and upload settings for M5Stack-ATOM

Setting	Value
Bootloader tool	esptool_py
Uploader tool	esptool_py
Network uploader tool	esp_ota
Bootloader address	`0x1000`
Flash mode	dio
Boot mode	dio
Maximum upload size	1280 KB (1310720 bytes)
Maximum data size	320 KB (327680 bytes)