M5Unified

M5Unified

Arduino / ESP-IDF Library for M5Stack Series

Usage

This library provides access to the built-in hardware of M5Stack controllers. Library functionality is available through the m5 namespace, and includes the following:

• LCD display access, fonts, and graphical primitives (in conjunction with M5GFX)
• Touchscreen and hardware button access
• Speaker and microphone access
• Power and battery charging control
• Accelerometer, gyroscope, magnetometer access
• Real-time clock and wakeup timer access

M5Unified requires M5GFX to be installed.

How To Use

#include "M5Unified.h"

Examples and Demonstrations

In the Arduino IDE, once the M5Unified library is installed through Library Manager, the following example programs are available under File > Examples > M5Unified > Basic.

• Combined demonstration: A demonstration exhibiting several functions in a single example is in HowToUse

Separate examples

• Displays: A basic demonstration of printing text on each of the supported M5Stack displays is in Displays.
• Buttons: A demo of detecting and responding to button presses is in Button.
• Touch: A demo of detecting and reacting to touch events is in Touch.
• Speaker: An example of playing wave audio through built-in speakers and accessories that support audio is in Speaker
• Clock: An example of connecting to an Internet time server over WiFi and setting the built-in clock is in RTC.
• Microphone: An example that records a short clip and plays it back through the speaker is in Microphone.
• IMU: An example demonstrating the accelerometer / gyro / magnetometer is in IMU
• Advanced examples include playing audio over Bluetooth and streaming and decoding MP3 audio, and are in the Advanced folder.

M5Stack hardware functionality supported by the ESP32 ecosystem

The following functionality is built in to the ESP32 framework or available elsewhere, independent of any hardware included in the M5Stack products, and do not require or have explicit support in the M5Unified library. To use these functions, simply use existing ESP32 or Arduino supporting libraries. This list is provided for the benefit of newcomers who may be asking where the “M5Unified” support for a particular feature is found, before discovering that it’s either already part of the basic ESP32 platform, or a device that is generic enough (e.g. I2C or SPI) to be fully supported with generic libraries found online, including in the Arduino library manager, that work with any platform.

• Network access using WiFi (built into ESP32)
• Micro SD card access (SD cards are generic SPI devices)
• Infrared remote control transmitter
• Color-changing LED (e.g. on Atom)

Desirable examples worthy of future contribution

• Power: A demonstration of detecting the battery level and charging state, powering off, and entering deep sleep mode when power off is unavailable.
• Battery lifespan management: An example/utility sketch that runs the battery down to an optimum storage percentage (~40%) before powering off as fully as possible, and as a separate function, charges it to a lifespan-preserving 75% maximum, on each M5Stack device where the power management hardware supports this.
• RTC wakeup: A demonstration of using the realtime clock to set a wakeup timer to power-on, or bring the device out of sleep mode after a pre-determined number of seconds, on devices that support this.

Supported frameworks

• ESP-IDF
• Arduino IDE

Supported devices (ESP32)

• M5Stack Core (BASIC / GRAY / GO / FIRE)
• M5Stack Core2 / Core2 v1.1 / Tough
• M5Stick C / CPlus / CPlus2
• M5Stack CoreInk
• M5Station
• M5Paper
• M5ATOM Lite / Matrix / ECHO / PSRAM / U
• M5STAMP PICO

Supported devices (ESP32-S3)

• M5Stack CoreS3 / CoreS3SE
• M5StickS3
• M5ATOMS3 / S3Lite / S3U
• M5ATOMS3R / S3RExt / S3RCam / ECHO S3R
• M5STAMPS3 (S3 / S3A) / S3Bat / S3Mini
• M5STAMPPLC
• M5Dial
• M5DinMeter
• M5Capsule
• M5Cardputer / M5CardputerADV
• M5VAMeter
• M5AirQ
• M5PaperS3
• M5PaperColor
• M5PaperMono
• M5PaperDIY
• M5PowerHub
• M5StopWatch
• M5StackChan
• M5ChainCaptain
• M5DualKey

Supported devices (ESP32-C3)

• M5STAMPC3 / C3U

Supported devices (ESP32-C5)

• M5STAMPC5
• M5ToughC5

Supported devices (ESP32-C6)

• M5NanoC6
• M5UnitC6L
• M5STAMPC6
• ArduinoNessoN1

Supported devices (ESP32-H2)

• M5NanoH2

Supported devices (ESP32-P4)

• M5Tab5
• M5STAMPP4
• M5UnitPoEP4

Supported external displays and video adapters

• Unit LCD
• Unit OLED
• Unit Mini OLED
• Unit RCA (without ESP32S3 series)
• Unit GLASS
• Unit GLASS2
• ATOM Display adapter (HDMI output for M5ATOM Lite / Matrix / PSRAM / S3 / S3Lite / S3R / S3RCam / S3RExt )
• Module Display adapter (HDMI output for M5Stack Core / Core2 / Tough / CoreS3 / CoreS3SE )
• Module RCA adapter (composite NTSC/PAL output for M5Stack Core / Core2 / Tough / (without ESP32S3 series))

Supported external speakers and audio adapters

• SPK HAT (with M5StickC / CPlus / M5Stack CoreInk)
• SPK HAT2 (with M5StickCPlus)
• ATOMIC SPK (with M5ATOM Lite / PSRAM / S3 / S3Lite / S3R / S3RCam / S3RExt )
• ATOMIC ECHO BASE (with M5ATOM Lite / PSRAM / S3 / S3Lite / S3R / S3RCam / S3RExt )
• Module Display adapter (Audio over HDMI for M5Stack Core / Core2 / Tough / CoreS3 / CoreS3SE )
• Module RCA adapter (M5Stack Core / Core2 / Tough)

Other supported external accessories

• Unit RTC
• Unit IMU

Notes

Arduino as an ESP-IDF component

When arduino-esp32 is used as an ESP-IDF component together with this library, the library links the Arduino component automatically (it looks for a component named arduino, arduino-esp32 or espressif__arduino-esp32 in the build) so that it is compiled with the same ARDUINO definitions as the application. Without that, the application and the library would see different layouts of the same classes. Set M5UNIFIED_ARDUINO_COMPONENT=<name> (CMake cache variable) if your Arduino component has another name, or M5UNIFIED_ARDUINO_COMPONENT=OFF to disable this.

Hardware information

ESP32 GPIO list

	M5Stack BASIC GRAY	M5Stack GO/FIRE	M5Stack Core2(AWS) Tough	M5Stick C/CPlus	M5Stick CPlus2	M5Stack CoreInk	M5Paper	M5Station	M5ATOM Lite/Matrix ECHO/U PSRAM	M5STAMP PICO
GPIO 0 ADC2_CH1	M-Bus IIS_MK	M-Bus IIS_MK	M-Bus SPK_LRCK PDM_C(Core2)	HAT PAD PDM_C	HAT PDM_C	EPD_RST	—	—	—		GPIO 0 ADC2_CH1
GPIO 1 USB_TX	M-Bus Serial	M-Bus Serial	M-Bus Serial	Serial	Serial	Serial	Serial	Serial	Serial	Serial	GPIO 1 USB_TX
GPIO 2 ADC2_CH2	M-Bus	M-Bus	M-Bus SPK_D	PAD Beep(CPlus)	Beep	Beep	PW_Hold	ReadEn	—	—	GPIO 2 ADC2_CH2
GPIO 3 USB_RX	M-Bus Serial	M-Bus Serial	M-Bus Serial	Serial	Serial	Serial	Serial	Serial	Serial	Serial	GPIO 3 USB_RX
GPIO 4 ADC2_CH0	TF_CS	TF_CS	TF_CS	—	PW_Hold	EPD_BUSY	TF_CS	RGB LED	—	—	GPIO 4 ADC2_CH0
GPIO 5	M-Bus	M-Bus	LCD_CS	LCD_CS	LCD_CS	BTN_HAT	EXT_5V	LCD_CS	Bus(P) PDM_C(U)	—	GPIO 5
GPIO 9	—	—	—	InfraRed	—	EPD_CS	—	—	—	—	GPIO 9
GPIO10	—	—	—	LED	—	LED	—	—	—	—	GPIO10
GPIO12 ADC2_CH5	M-Bus IIS_SK	M-Bus IIS_SK	SPK_BCLK	—	LCD_RST	PW_Hold	SPI_MOSI	USB_PW	InfraRed	—	GPIO12 ADC2_CH5
GPIO13 ADC2_CH4	M-Bus IIS_WS	M-Bus IIS_WS	M-Bus RXD2	SPI_SCLK	SPI_SCLK	MI-Bus RXD2	SPI_MISO	PORT.C1	—	—	GPIO13 ADC2_CH4
GPIO14 ADC2_CH6	LCD_CS	LCD_CS	M-Bus TXD2	—	LCD_D/C	MI-Bus TXD2	SPI_SCLK	PORT.C1	—	—	GPIO14 ADC2_CH6
GPIO15 ADC2_CH3	M-Bus IIS_OUT	M-Bus RGB LED	LCD_D/C	SPI_MOSI	SPI_MOSI	EPD_D/C	EPD_CS	LCD_RST	—	—	GPIO15 ADC2_CH3
GPIO16 PSRAM	M-Bus RXD2	M-Bus PORT.C RXD2	—	—	—	—	—	PORT.C2 RXD2	—	—	GPIO16 PSRAM
GPIO17 PSRAM	M-Bus TXD2	M-Bus PORT.C TXD2	—	—	—	—	—	PORT.C2 TXD2	—	—	GPIO17 PSRAM
GPIO18	M-Bus SPI_SCLK	M-Bus SPI_SCLK	SPI_SCLK	LCD_RST	—	MI-Bus SPI_SCLK	PORT.C	SPI_SCLK	—		GPIO18
GPIO19	M-Bus SPI_MISO	M-Bus SPI_MISO	M-Bus	—	LED InfraRed	RTC_INT	PORT.C	LCD_D/C	Bus SPK_C(ECHO) *PDM_D(U)		GPIO19
GPIO21	M-Bus PORT.A I2C0_SDA	M-Bus PORT.A I2C0_SDA	I2C1_SDA	I2C1_SDA	I2C1_SDA	MI-Bus I2C1_SDA	I2C1_SDA	I2C1_SDA	Bus I2C1_SCL		GPIO21
GPIO22	M-Bus PORT.A I2C0_SCL	M-Bus PORT.A I2C0_SCL	I2C1_SCL	I2C1_SCL	I2C1_SCL	MI-Bus I2C1_SCL	I2C1_SCL	I2C1_SCL	Bus SPK_D(ECHO)		GPIO22
GPIO23	M-Bus SPI_MOSI	M-Bus SPI_MOSI	SPI_MOSI	LCD_D/C	—	MI-Bus SPI_MOSI	EPD_RST	SPI_MOSI	Bus PDM_D(ECHO)	—	GPIO23
GPIO25 DAC1	M-Bus SPK_DAC	M-Bus SPK_DAC	M-Bus RGB LED(AWS)	HAT(CPlus) PAD	HAT	MI-Bus HAT	PORT.A I2C0_SDA	PORT.B1	Bus I2C1_SDA		GPIO25 DAC1
GPIO26 DAC2	M-Bus	M-Bus PORT.B	M-Bus	HAT PAD	HAT	MI-Bus HAT	PORT.B	PORT.B2	PORT.A I2C0_SDA		GPIO26 DAC2
GPIO27 ADC2_CH7	LCD_D/C	LCD_D/C	M-Bus	AXP192 VBUSEN	LCD_BL	BTN_PWR	EPD_BUSY	IMU_INT	RGB LED	RGB LED	GPIO27 ADC2_CH7
GPIO32 ADC1_CH4	LCD_BL	LCD_BL	M-Bus PORT.A I2C0_SDA	PORT.A I2C0_SDA	PORT.A I2C0_SDA	PORT.A I2C0_SDA	PORT.A I2C0_SCL	PORT.A I2C0_SDA	PORT.A I2C0_SCL	PORT.A I2C0_SDA	GPIO32 ADC1_CH4
GPIO33 ADC1_CH5	LCD_RST	LCD_RST	M-Bus PORT.A I2C0_SCL	PORT.A I2C0_SCL	PORT.A I2C0_SCL	PORT.A I2C0_SCL	PORT.B	PORT.A I2C0_SCL	Bus PDM_C(ECHO)	PORT.A I2C0_SCL	GPIO33 ADC1_CH5
GPIO34 ADC1_CH6	M-Bus IIS_IN	M-Bus MIC_ADC IIS_IN	M-Bus PDM_D(Core2)	PDM_D	PDM_D	MI-Bus SPI_MISO	—	USB Current?		—	GPIO34 ADC1_CH6
GPIO35 ADC1_CH7	M-Bus	M-Bus	M-Bus	RTC_INT	BTN_PWR	BAT_V	BAT_V	PORT.B1	—	—	GPIO35 ADC1_CH7
GPIO36 ADC1_CH0	M-Bus	M-Bus PORT.B	M-Bus	HAT PAD	HAT	MI-Bus HAT	TP_INT	PORT.B2	—	—	GPIO36 ADC1_CH0
GPIO37 ADC1_CH1	BTN_C	BTN_C	—	BTN_A	BTN_A	SW_Up	SW_Up	BTN_A	—	—	GPIO37 ADC1_CH1
GPIO38 ADC1_CH2	BTN_B	BTN_B	M-Bus SPI_MISO	PAD	BAT_V	SW_Press	SW_Press	BTN_B	—	—	GPIO38 ADC1_CH2
GPIO39 ADC1_CH3	BTN_A	BTN_A	TP_INT	BTN_B	BTN_B	SW_Down	SW_Down	BTN_C	BTN	BTN	GPIO39 ADC1_CH3
	M5Stack BASIC GRAY	M5Stack GO/FIRE	M5Stack Core2(AWS) Tough	M5Stick C/CPlus	M5Stick CPlus2	M5Stack CoreInk	M5Paper	M5Station	M5ATOM Lite/Matrix ECHO/U PSRAM	M5STAMP PICO

ESP32C3 GPIO list

	M5Stamp C3	M5Stamp C3U
GPIO 0	PORT.A I2C0_SCL	PORT.A I2C_SCL	GPIO 0
GPIO 1	PORT.A I2C0_SDA	PORT.A I2C_SDA	GPIO 1
GPIO 2	RGB LED	RGB LED	GPIO 2
GPIO 3	BTN_A	Bus	GPIO 3
GPIO 4	Bus	Bus	GPIO 4
GPIO 5	Bus	Bus	GPIO 5
GPIO 6	Bus	Bus	GPIO 6
GPIO 7	Bus	Bus	GPIO 7
GPIO 8	Bus	Bus	GPIO 8
GPIO 9	—	BTN_A	GPIO 9
GPIO10	Bus	Bus	GPIO10
GPIO18 USB	PORT.U D-	USB PORT.U D-	GPIO18 USB
GPIO19 USB	PORT.U D+	USB PORT.U D+	GPIO19 USB
GPIO20	USB Serial	Bus	GPIO20
GPIO21	USB Serial	Bus	GPIO21
	M5Stamp C3	M5Stamp C3U

ESP32S3 GPIO list

	M5Stack CoreS3 CoreS3SE	M5ATOMS3R / S3RCam	M5ATOMS3 / S3Lite	M5ATOMS3U	M5STAMPS3	M5Dial	M5Capsule	M5Cardputer
GPIO 0	M-Bus SPK_LRCK	I2Cx_SCL forIMU	—	—	Bus BTN_A	—	—	BTN_A	GPIO 0
GPIO 1	PORT.A I2C0_SCL	PORT.A I2C0_SCL	PORT.A I2C0_SCL	PORT.A I2C0_SCL	Bus	PORT.B	—	PORT.A I2C0_SCL	GPIO 1
GPIO 2	PORT.A I2C0_SDA	PORT.A I2C0_SDA	PORT.A I2C0_SDA	PORT.A I2C0_SDA	Bus	PORT.B	Beep	PORT.A I2C0_SDA	GPIO 2
GPIO 3	LCD_CS	CAM_Y2	vdd3v3	vdd3v3	Bus	Beep	—	KEY_MATRIX	GPIO 3
GPIO 4	TF_CS	CAM_Y6	InfraRed	—	Bus	LCD_RS	InfraRed	KEY_MATRIX	GPIO 4
GPIO 5	M-Bus	Bus	Bus	—	Bus	LCD_MOSI	—	KEY_MATRIX	GPIO 5
GPIO 6	M-Bus	Bus	Bus	—	Bus	LCD_SCK	BAT_ADC	KEY_MATRIX	GPIO 6
GPIO 7	M-Bus	Bus	Bus	—	Bus	LCD_CS	—	KEY_MATRIX	GPIO 7
GPIO 8	M-Bus PORT.B	Bus	Bus	—	Bus	LCD_RST	I2C1_SDA	KEY_MATRIX	GPIO 8
GPIO 9	M-Bus PORT.B	I2Cy_SCL forCam	—	—	Bus	LCD_BL	—	KEY_MATRIX	GPIO 9
GPIO10	M-Bus	CAM_VSYNC	—	—	Bus	RFID_INT	I2C1_SCL	BAT_ADC	GPIO10
GPIO11	I2C1_SCL	CAM_Y8	—	—	Bus	I2C1_SDA	TF_CS	KEY_MATRIX	GPIO11
GPIO12	I2C1_SDA	I2Cy_SDA forCam	—	InfraRed	Bus	I2C1_SCL	TF_MOSI	TF_CS	GPIO12
GPIO13	M-Bus SPK_D	CAM_Y9	—	—	Bus PORT.A I2C0_SDA	PORT.A I2C0_SDA	PORT.A I2C0_SDA	KEY_MATRIX	GPIO13
GPIO14	M-Bus MIC_IN	LCD_CS CAM_HREF	—	Bus	Bus	TP_INT	TF_CLK	TF_MOSI	GPIO14
GPIO15	CAM_D6	LCD_SCLK	LCD_CS	—	Bus PORT.A I2C0_SCL	PORT.A I2C0_SCL	PORT.A I2C0_SCL	KEY_MATRIX	GPIO15
GPIO16	CAM_D7	IMU_INT	LCD_BL	—	FPC	—	—	—	GPIO16
GPIO17	M-Bus PORT.C	CAM_Y7	LCD_SCLK	Bus	FPC	—	—	—	GPIO17
GPIO18	M-Bus PORT.C	POWER_N	—	—	FPC	—	—	—	GPIO18
GPIO19 USB	USB D–	USB D–	USB D–	USB D–	USB D–	USB D–	USB D–	USB D–	GPIO19 USB
GPIO20 USB	USB D++	USB D++	USB D++	USB D++	USB D++	USB D++	USB D++	USB D++	GPIO20 USB
GPIO21	I2C_INT	LCD_MOSI CAM_XCLK	LCD_MOSI	—	RGB LED	RGB LED	RGB LED	RGB_LED	GPIO21
GPIO33	SPK_WCK	OPI PSRAM	LCD_DC	—	FPC	—	—	LCD_RST	GPIO33
GPIO34	SPK_BCK	OPI PSRAM	LCD_RST	—	FPC	—	—	LCD_RS	GPIO34
GPIO35	M-Bus SPI_MISO LCD DC	OPI PSRAM	RGB LED	RGB LED	FPC	—	—	LCD_DAT	GPIO35
GPIO36	M-Bus SPI_SCLK	OPI PSRAM	—	—	FPC	—	—	LCD_SCK	GPIO36
GPIO37	M-Bus SPI_MOSI	OPI PSRAM	—	—	FPC	—	—	LCD_CS	GPIO37
GPIO38	CAM_HREF	Bus	Bus I2C1_SDA	PDM_DAT	FPC	—	—	LCD_BL	GPIO38
GPIO39	CAM_D2	Bus	Bus I2C1_SCL	PDM_CLK	Bus	—	TF_MISO	TF_MISO	GPIO39
GPIO40	CAM_D3	CAM_PCLK	—	Bus	Bus	ENCODER_B	MIC_CLK	TF_CLK	GPIO40
GPIO41	CAM_D4	BTN_A	BTN_A	BTN_A	Bus	ENCODER_A	MIC_DAT	SPK_BCLK	GPIO41
GPIO42	CAM_D5	LCD_D/D CAM_Y3	—	Bus	Bus	BTN_A	BTN_A	SPK_SDATA	GPIO42
GPIO43	M-Bus SerialTX	—	—	—	Bus	—	—	I2S_LRCLK	GPIO43
GPIO44	M-Bus SerialRX	—	—	—	Bus	—	—	InfraRed	GPIO44
GPIO45	CAM_PCLK	I2Cx_SDA forIMU	—	—	—	—	—	—	GPIO45
GPIO46	CAM_VSYNC	CAM_Y4	—	—	Bus	HOLD	HOLD	MIC_DAT	GPIO46
GPIO47	CAM_D9	InfraRed	—	—	—	—	—	—	GPIO47
GPIO48	CAM_D8	LCD_RST CAM_Y5	—	—	—	—	—	—	GPIO48
	M5Stack CoreS3	M5ATOMS3R / S3RCam	M5ATOMS3 / S3Lite	M5ATOMS3U	M5STAMPS3	M5Dial	M5Capsule	M5Cardputer

AXP192 power management IC connections

	M5Stack Core2	M5Stack Tough	M5Stick C	M5Stick CPlus	M5Station
GPIO0 LDO0	BUS PW EN	BUS PW EN	MIC VCC	MIC VCC	PortA1.A2 EN	GPIO0 LDO0
GPIO1	SYS LED	TP RST	—	—	PortB1 EN	GPIO1
GPIO2	SPK EN	SPK EN	—	—	PortB2 EN	GPIO2
GPIO3	—	—	—	—	PortC1 EN	GPIO3
GPIO4	LCD RST TP RST	LCD RST	—	—	PortC2 EN	GPIO4
EXTEN	PORT 5V EN	PORT 5V EN	PORT 5V EN	PORT 5V EN	PORT 5V EN	EXTEN
BACKUP	RTC BAT	RTC BAT	RTC BAT	RTC BAT	—	BACKUP
LDO1	RTC VDD	RTC VDD	RTC VDD	RTC VDD	RTC VDD	LDO1
LDO2	LCD PW Periph PW	LCD PW Periph PW	LCD BL	LCD BL	—	LDO2
LDO3	VIB MOTOR	LCD BL	LCD PW	LCD PW	LCD BL	LDO3
DCDC1	ESP32 VDD	ESP32 VDD	ESP32 VDD	ESP32 VDD	ESP32 VDD	DCDC1
DCDC2	—	—	—	—	—	DCDC2
DCDC3	LCD BL	—	—	—	—	DCDC3

AXP2101 usage

	M5Stack Core2v1.1	M5Stack CoreS3 CoreS3SE
ALDO1	—	VDD 1v8	ALDO1
ALDO2	LCD RST	VDDA 3v3	ALDO2
ALDO3	SPK EN	CAM 3v3	ALDO3
ALDO4	Periph PW TF,TP,LCD	TF 3v3	ALDO4
BLDO1	LCD BL	AVDD	BLDO1
BLDO2	PORT 5V EN	DVDD	BLDO2
DLDO1/DC1	VIB MOTOR	LCD BL	DLDO1/DC1
DLDO2/DC2	—	—	DLDO2/DC2
BACKUP	RTC BAT	RTC BAT	BACKUP

PinMap

	M5Stack BASIC/GRAY GO/FIRE FACES II	M5Stack Core2 Core2AWS TOUGH	M5Stack CoreS3 CoreS3SE
Bus	M-Bus	M-Bus	M-Bus
	※ HPWR=not connected to the ESP32. Used by modules capable of supplying 12V power.

	M5Stack BASIC/GRAY GO/FIRE FACES II	M5Stack Core2 Core2AWS TOUGH	M5Stack CoreS3	M5Paper	M5Station
PortA	PortA	PortA	PortA	PortA	PortA
PortB	PortB	PortB	PortB	PortB	PortB1	PortB2
PortC	PortC	PortC	PortC	PortC	PortC1	PortC2
PortD	PortD	PortD
PortE	PortE	PortE / 485 TOUGH485:12V

	M5Stick C	M5Stick C Plus	M5Stack CoreInk	M5Stamp PICO	M5Stamp C3	M5Stamp C3U
PortA
HAT
Bus			MI-Bus

	ATOM Lite	ATOM Matrix	ATOM ECHO	ATOM PSRAM	ATOM U
PortA
Bus

	ATOMS3 /S3Lite	NanoC6/Cardputer
PortA
Bus

SPI device

	M5Stack BASIC GRAY GO/FIRE	M5Stack Core2 Tough	M5Stick C	M5Stick CPlus	M5Stack CoreInk	M5Paper
Display	ILI9342C 320×240 CS:G14	ILI9342C 320×240 CS:G5	ST7735S 80×160 CS:G5	ST7789V2 135×240 CS:G5	GDEW0154M09 200×200 CS:G9	IT8951 960×540 CS:G15	Display
TF Card	CS:4	CS:4	—	—	—	CS:4	TF Card

I2C device

	M5Stack BASIC/GRAY GO/FIRE	M5Stack Core2	M5Stack Tough	M5Stack CoreS3	M5Stick C CPlus	M5Stack CoreInk	M5Paper	ATOM Matrix	M5Station
Touch Panel	—	FT6336U 38h	CHSC6540 2Eh	FT5xxx 38h	—	—	GT911 14h or 5Dh	—	—	Touch Panel
RTC	—	BM8563 51h	BM8563 51h	BM8563 51h	BM8563 51h	BM8563 51h	BM8563 51h	—	BM8563 51h	RTC
Power Manage	IP5306 75h	AXP192 34h	AXP192 34h	AXP2101 34h	AXP192 34h	—	—	—	AXP192 34h	Power Manage
IMU	MPU6886 68h	MPU6886 68h (Ext)	—	BMI270 69h	MPU6886 68h	—	—	MPU6886 68h	MPU6886 68h (opt)	IMU
IMU (old lot)	SH200Q 6Ch	—	—	—	SH200Q 6Ch	—	—	—	—	IMU (old lot)
ENV	—	—	—	LTR553ALS 23h	—	—	SHT30 44h	—	—	ENV
EEPROM	—	—	—	—	—	—	FM24C02 50h	—	—	EEPROM
Camera	—	—	—	GC0308 21h	—	—	—	—	—	Camera
Speaker	—	—	—	AW88298 36h	—	—	—	—	—	Speaker
Microphone	—	—	—	ES7210 40h	—	—	—	—	—	Microphone
GPIO Expander	—	—	—	AW9523B 58h	—	—	—	—	—	GPIO Expander
Current Voltage Monitor	—	—	—	—	—	—	—	—	INA3221 40h/41h (opt)	Current Voltage Monitor

Fixed-board firmware

Defining a positive BOARD_ID when building an application using M5Unified fixes its device identity to that board_t value. An undefined, explicitly empty, or zero value keeps automatic detection. Fixed startup reads only variants needed by the selected board and does not use NVS or probe other board families. An accepted fixed identity takes precedence over config_t::fallback_board, including when display startup fails. Call M5.begin() before initializing M5.Display for this configuration to take effect.

A positive BOARD_ID unsupported by the chip also stops automatic detection; it does not fall back to probing another board. BOARD_ID has no effect if M5.Display.init() runs before M5.begin(). A valueless compiler option -DBOARD_ID defines the value as 1 (M5Stack), rather than an empty value.