The M5Stack is an ESP32-based development kit from M5Stack. The M5Stack resembles a finished solution featuring an industrial-grade case and LCD screen, and the kit contains a lithium battery, M-BUS socket, and extendable pins on both sides.

Project Specifics

Having both BLE and Wi-Fi connectivity options, M5Stack projects include the following protocol elements:

BLECharacteristicElement icon for the element library

BLE Characteristic

BLEConnectionElement icon for the element library

BLE Connection

Wi-FiConnectionElement icon for the element library

Wi-Fi Connection

As is standard with any project type that uses Wi-Fi, cloud elements are accessible from both the Embedded and Application tabs in Atmosphere Studio.

Hardware Specifics

Some devices may have limitations or design restrictions that cause unexpected behavior when used with Atmosphere. Specific information and details pertaining to the M5Stack and its performance on Atmosphere is noted below.

  • ADC2 is not accessible, since it conflicts with the Wi-Fi. This means that pins IO4, IO0, IO2, IO15, IO13, IO12, IO14, IO27, IO25, and IO26 cannot be used as analog input pins.

Default Pin Mapping

Atmosphere configures each peripheral to a default pin for every supported device, based on ideal pairing of pins and their usage. The default pin configuration is set for convenience and enables each peripheral to work naturally without needing to be modified.

All pins can be used as general purpose input/output (GPIO) unless otherwise specified.

M5Stack projects start with the following pin configuration:

Pin Table

Pin Description Notes
ESP32_UART1_TX UART1 TX Pin Maps to IO4
ESP32_UART1_RX UART1 RX Pin Maps to IO5
ESP32_UART2_TX UART2 TX Pin Maps to IO1
ESP32_UART2_RX UART2 RX Pin Maps to IO3
ESP32_I2C_SDA I2C SDA Maps to IO21
ESP32_I2C_SCL I2C SCL Maps to IO22
M5STACK_BUTTON_A Button A Maps to IO39
M5STACK_BUTTON_B Button B Maps to IO38
M5STACK_BUTTON_C Button C Maps to IO37
M5STACK_SPEAKER Speaker Maps to IO25

Internal ESP32 Pins

All internal pins can be accessed using the following nomenclature: IO[PIN] OR GPIO_NUM_[PIN]. For example, pin 12 can be accessed via IO12 or GPIO_NUM_12.

The default pin for any peripheral can be changed within an element's properties, from an element that references that particular peripheral.


Below is information regarding the M5Stack’s exposed peripherals.



This I2C bus is exposed via pins IO21(SDA) and IO22(SCL).



This SPI bus is exposed via pins IO23(MOSI), IO19(MISO), and IO18(CLK).


UART1 (USB Debug Console)

This UART is exposed via the micro-USB connector on the M5Stack or pins IO4(TX) and IO5(RX).


This UART is exposed via pins IO1(TX) and IO3(RX).


ADC2 cannot be used, since it conflicts with the Wi-Fi. The following pins can be used for analog input:

  • IO36
  • IO37
  • IO38
  • IO39
  • IO32
  • IO33
  • IO34
  • IO35


Any GPIO pin can be used for PWM output.

Programming Method

Programming the M5Stack involves using the programmer interface in Atmosphere Studio to install embedded firmware.

Setup Configuration

Prior to programming an M5Stack, ensure you have the following setup configuration:

  • The M5Stack is connected to the computer via USB to an available communication port.
  • The computer has the necessary connectivity protocols enabled (Bluetooth Low Energy, Wi-Fi, etc.).
  • The Atmosphere IoT Agent is installed on the computer and running. This is a local application that runs in the system tray and acts as an intermediary between the computer’s connectivity protocol drivers and the browser running Atmosphere.
  • An Internet connection is maintained.
  • The project to be programmed has been compiled.

Programming Instructions

With setup complete, you can program the M5Stack:

  1. From Atmosphere Studio’s Embedded tab, click the Program Firmware button from the tab’s toolbar. This displays the Program Firmware window.
  2. Under Device Port, select the communication port the device is connected to.
  3. Click Program to start programming. When complete, you’ll be notified that the device is programmed with the project’s embedded firmware.

When complete, the M5Stack is programmed with the project’s embedded firmware.

Guides and Tutorials

Get started using the M5Stack with Atmosphere by walking through the following guides:

M5Stack Guides
Getting Started with ESP32

Demo Projects

There are currently no demo projects available for the M5Stack.


The following additional resources and downloadable files are available for the M5Stack: