M5Stack-FIRE
Enhanced Core ESP32 with extra sensors, mic, and IMU - ideal for edge AI and sensor fusion projects.
M5Stack-FIRE Pinout
20 pins
| Pin | GPIO | Labels | Status | Capabilities | Notes |
|---|---|---|---|---|---|
| 1 | 0 | G0 | strapping | - | |
| 2 | 1 | TXG1PWM | uart | uart | |
| 3 | 2 | G2PWM | strapping | - | |
| 4 | 3 | RXG3PWM | uart | uart | |
| 5 | 5 | SSG5PWM | strapping | spi | |
| 6 | 12 | G12PWM | strapping | - | |
| 7 | 13 | G13PWM | strapping | - | |
| 8 | 15 | G15PWM | strapping | - | |
| 9 | 16 | RXD2G16PWM | strapping | - | |
| 10 | 17 | TXD2G17PWM | strapping | - | |
| 11 | 18 | SCKG18PWM | safe | spi | |
| 12 | 19 | MISOG19PWM | safe | spi | |
| 13 | 21 | SDAG21PWM | safe | i2c | |
| 14 | 22 | SCLG22PWM | safe | i2c | |
| 15 | 23 | MOSIG23PWM | safe | spi | |
| 16 | 25 | G25DAC1PWM | safe | dac | |
| 17 | 26 | G26DAC2PWM | safe | dac | |
| 18 | 34 | G34 | strapping | - | |
| 19 | 35 | G35ADC1 | strapping | - | |
| 20 | 36 | G36ADC2 | strapping | - |
Start with these
7 pins with no boot or system involvementFreely assignable - no strapping, flash, USB or JTAG duties. Ideal first picks for buttons, sensors and LEDs.
Fine - with a little care
11 pins · 11 things to knowG0GPIO0 Bootstrapping pin (enter bootloader when low); internal pull-up. Strapping
Must be HIGH during boot for normal startup; if held LOW on reset, forces flash programming mode.
TXGPIO1 Default UART0 TX pin for USB-serial programming and console. UART
Connected to on-board USB-UART for uploading and logs; drives serial output at boot, so using as GPIO can disrupt programming or console.
G2GPIO2 Bootstrapping pin (must be low or floating at reset); internal pull-down. Strapping
If driven HIGH on reset (while IO0 is LOW), selects an unsupported SDIO boot mode, causing boot failure.
RXGPIO3 Default UART0 RX pin for USB-serial programming (console input). UART
Used for receiving data from USB-UART (programming); also pulled HIGH at boot for console communication, so using as GPIO can disrupt uploads.
SSGPIO5 Bootstrapping pin; internal pull-up; VSPI CS0 (default SPI chip-select); acts as FSPIWP (flash write-protect) on internal-flash variants. Strapping
Must be HIGH during boot; if pulled LOW at reset, alters SDIO slave timing and may prevent normal boot.
G12GPIO12 Bootstrapping pin; JTAG TDI; sets flash voltage (VDD_SDIO); also HSPIQ (flash data line). Strapping
Keep LOW during boot (internal PD); pulling HIGH at reset selects 1.8V flash mode, causing flash brownout if 3.3V flash is used.
G13GPIO13 JTAG clock pin (TCK); also ADC2 channel 4 / Touch4 input. JTAG
Used for JTAG debugging (TCK); avoid using as GPIO if JTAG is needed.
G15GPIO15 Bootstrapping pin; JTAG TDO; controls UART0 boot log output; also HSPICS0 (secondary SPI CS). Strapping
Keep HIGH during boot (internal PU); if LOW on reset, bootloader log is silenced and boot mode may change.
G34GPIO34 Input-only GPIO (no output driver); ADC1 channel 6. Other
Cannot be used as output (no drive capability); only suitable for analog/digital input.
G35GPIO35 Input-only GPIO (no output driver); ADC1 channel 7. Other
Cannot be used as output; only suitable for input.
G36GPIO36 Input-only GPIO (no output); ADC1 channel 0, Hall sensor VP. Other
Cannot be used as output; only suitable for input (e.g., analog read).
Only if you know the tricks
2 pins · 1 thing to knowRXD2GPIO16TXD2GPIO17 PSRAM chip select and clock on WROVER-class modules; in-package flash lines on ESP32-U4WDH. Both also carry UART2 PSRAM
Wired to the memory die on PSRAM-equipped modules (WROVER, PICO-V3-02) and on in-package-memory chip variants (U4WDH, D0WDRH2-V3); an ordinary GPIO on a plain WROOM-32.
- RXD2PSRAM CS# on WROVER-class modules and on ESP32-D0WDRH2-V3; in-package flash CS# on ESP32-U4WDH. Also UART2 RX.
- TXD2PSRAM clock on WROVER-class modules; in-package flash IO1/DO on ESP32-U4WDH. Also UART2 TX.
All 20 pins on the M5Stack-FIRE are usable GPIO.
Peripheral wiring is straightforward: I²C is mapped to SDA on GPIO21 and SCL on GPIO22; the SPI bus (MOSI, MISO, SCK, SS) is broken out in full; TX/RX on GPIO1 and GPIO3 cover serial logging and flashing.
Beyond plain digital I/O you get 2 true DAC outputs.
11 of the exposed pins carry boot-time or system duties on the ESP32 (G0, TX, G2 and 8 more) - check the guidance above before wiring anything to them. SCK, MISO, SDA, SCL and 3 more are free of any such role - the safest first picks.
Getting started
flash your first firmware in ~2 minutesBoard: ESP32 Wrover Module Flash Size: 16MB (128Mb) Flash Mode: DIO PSRAM: QSPI PSRAM Partition Scheme: 16M Flash (3MB APP/9.9MB FATFS) Upload Speed: 921600
// toggle GPIO18 - wire an LED and resistor to it
void setup() {
pinMode(18, OUTPUT);
}
void loop() {
digitalWrite(18, HIGH); delay(500);
digitalWrite(18, LOW); delay(500);
}[env:m5stack-fire]
platform = espressif32
board = esp32dev
framework = arduino
monitor_speed = 115200
upload_speed = 921600
board_build.arduino.memory_type = qio_qspi
build_flags = -DBOARD_HAS_PSRAMesp32dev - or type it after board =.esp32:
board: esp32dev
variant: esp32
framework:
type: esp-idf
psram:
mode: quad
speed: 80MHz
# blink - GPIO18
output:
- platform: gpio
pin: 18
id: led_out
light:
- platform: binary
name: "LED"
output: led_outesp32dev (same ids as PlatformIO).esptool.py --chip esp32 --port /dev/ttyACM0 \
--baud 921600 write_flash 0x1000 firmware.bin--port = your /dev/tty* (macOS/Linux) or COMx (Windows).Specifications
ESP32 · 54 × 54 mm · vs other ESP32 chips →Dimensions
About this board
Inside sits the ESP32 - a dual-core Xtensa with both Bluetooth Classic and BLE.
At $49.90 it's on the expensive side for an ESP32 board - most land around $20.
Around the module: 8MB (QSPI) PSRAM, an LCD 2.0" 320x240 display, a microSD slot, a microphone, a speaker, an MPU6886 + BMM150 IMU, an addressable RGB LED (GPIO15), battery charging (IP5306) and A/B/C buttons.
- Built-in 500mAh 3.7V LiPo battery
Where to buy
prices are typical street pricesResources
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