ESP32 Boards/ ESP32-H2 /Supermini

ESP32-H2 Super Mini

by Generic

Ultra-compact ESP32-H2 board with BLE and Thread - ideal for low-power mesh networks and Matter-ready IoT devices.

USB-C Native USB

Buy on AliExpress · $5.00 More sellers Pinout Datasheet ↗

23 × 18 mm

ESP32-H2

RISC-V MCU

96MHz

clock

4MB

flash

320KB

SRAM

19· 5 ADC

GPIO

BLE 5.0+ WiFi

radio

ESP32-H2 Super Mini Pinout

22 pins · 2.54 mm pitch

Pin	GPIO	Labels	Status	Capabilities	Notes
1	-	5V	power	-	5V power input for the board
2	-	GND	ground	-	Ground connection
3	-	3V33.3V	power	-	3.3V power output for peripherals
4	0	IO0GP0	strapping	-	GPIO
5	1	IO1GP1	strapping	adc	GPIO, ADC pin
6	2	IO2GP2	strapping	adc	GPIO, ADC pin
7	3	IO3GP3	strapping	adc	GPIO, ADC pin
8	4	IO4GP4	strapping	adc	GPIO, ADC pin
9	5	IO5GP5	strapping	adc	GPIO, ADC pin
10	8	IO8GP8	strapping	-	GPIO, LOG
11	9	IO9GP9	strapping	-	GPIO, BOOT
12	10	IO10GP10	safe	-	GPIO
13	11	IO11GP11	safe	-	GPIO
14	12	IO12GP12	safe	-	GPIO
15	13	IO13GP13	safe	-	GPIO, LED
16	14	IO14GP14	safe	-	GPIO
17	22	IO22GP22	safe	-	GPIO
18	24	TXIO24	uart	uart	TX
19	23	IO23GP23	uart	-	GPIO
20	25	IO25GP25	strapping	-	GPIO
21	26	IO26GP26	uart	-	GPIO
22	27	IO27GP27	uart	-	GPIO

19 GPIOs broken out 6 free · 11 need care · 2 to avoid

Start with these

6 pins with no boot or system involvement

IO10IO11IO12IO13IO14IO22

Freely assignable - no strapping, flash, USB or JTAG duties. Ideal first picks for buttons, sensors and LEDs.

Fine - with a little care

11 pins · 10 things to know

IO0IO1 General-purpose SPI2 (FSPI) IO MUX pins Other

IO MUX pin of the general-purpose SPI2 (FSPI) bus. The H2 runs its in-package flash on GPIO15-20, which the QFN32 package does not route out, so this pin is free unless your board wires an SPI peripheral to FSPI.

IO0General-purpose SPI2 (FSPI) IO MUX pin - data out (FSPIQ)
IO1General-purpose SPI2 (FSPI) IO MUX pin - chip select (FSPICS0)

IO2 JTAG TMS signal; also the general-purpose SPI2 (FSPI) write-protect/data line (FSPIWP) JTAG

Default JTAG TMS line - using it as GPIO disables external JTAG debugging. It is not a flash pin: the H2 keeps its in-package flash on GPIO15-20, which the QFN32 package does not route out.

IO3 JTAG TDO signal; also the general-purpose SPI2 (FSPI) hold/data line (FSPIHD) JTAG

Default JTAG TDO line - using it as GPIO disables external JTAG debugging. It is not a flash pin: the H2 keeps its in-package flash on GPIO15-20, which the QFN32 package does not route out.

IO4 JTAG TCK signal; also the general-purpose SPI2 (FSPI) clock (FSPICLK) JTAG

Default JTAG TCK line - using it as GPIO disables external JTAG debugging. It is not a flash pin: the H2 keeps its in-package flash on GPIO15-20, which the QFN32 package does not route out.

IO5 JTAG TDI signal; also the general-purpose SPI2 (FSPI) data in (FSPID) JTAG

Default JTAG TDI line - using it as GPIO disables external JTAG debugging. It is not a flash pin: the H2 keeps its in-package flash on GPIO15-20, which the QFN32 package does not route out.

IO8 Bootstrapping pin; controls chip boot mode and ROM debug message printing. Strapping

Must be held at the proper logic level on reset to select the correct boot mode and enable/disable bootloader log output.

IO9 Bootstrapping pin; controls chip boot mode (with GPIO8). Strapping

Must be pulled high on reset for normal SPI flash boot (pulling it low while GPIO8 is high forces the chip into download/programming mode).

TXGPIO24 UART0 TXD (transmit) pin, default serial console output. UART

Often used for boot log output and serial debugging; repurposing it can disable serial output of boot messages and interfere with console debugging.

IO23 UART0 RXD (receive) pin, default serial console input. UART

Often used for the serial console and bootloader input; repurposing it may conflict with UART communication for programming or debugging.

IO25 Bootstrapping pin; selects JTAG signal source (USB Serial/JTAG controller vs. external JTAG). Strapping

Used during boot to determine the JTAG interface source; this pin has no internal pull-up/down, so it must not be left floating (an external resistor drives it high/low to avoid unintended JTAG mode selection).

Only if you know the tricks

2 pins · 2 things to know

IO26 USB D- connection pin (USB Serial/JTAG controller interface). USB

By default, this pin is connected to the chip's internal USB Serial/JTAG peripheral; using it as a general-purpose IO requires disabling or reconfiguring that USB interface.

IO27 USB D+ connection pin (with internal USB pull-up). USB

By default, this pin is connected to the internal USB Serial/JTAG controller; using it as a general-purpose IO would disable the USB functionality used for debugging/programming.

These are recommendations, not hard rules - with the right pull-ups, timing and boot-state awareness most pins can be made to work. When in doubt, start green.

The ESP32-H2 Super Mini breaks out 22 pins in total: 19 GPIO for your project, with 5V, GND and 3V3 handling power.

On the analog side there are 5 ADC-capable pins for sensors and battery monitoring.

If you want zero surprises, IO10, IO11, IO12, IO13 and 2 more are free of any such role - the safest first picks. 11 of the exposed pins carry boot-time or system duties on the ESP32-H2 (IO0, IO1, IO2 and 8 more).

Guides & tutorials

Comparison ESP32 Super Mini boards compared C3 vs C3 Plus vs C6 vs S3 - which tiny board fits your project. 8 min read→

Getting started

flash your first firmware in ~2 minutes

Tool:

Connect over USB

Native USB - shows up as a port right away, no driver needed. Not detected? Hold BOOT while plugging in.

Match & flash

Set the Tools options shown, then click Upload.

Verify it runs

GPIO10 toggles - wire an LED and resistor to it, or change the pin to your board's own LED.

Set these in Tools · leave everything else at default

Arduino IDE 2.x - Tools Copy

Board: "ESP32H2 Dev Module"▸

USB CDC On Boot: "Enabled"▸

Flash Size: "4MB (32Mb)"▸

Flash Mode: "QIO"▸

Partition Scheme: "Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS)" (default)▸

Upload Speed: "921600"▸

▸ every other Tools option - leave at default

Board: ESP32H2 Dev Module
USB CDC On Boot: Enabled
Flash Size: 4MB (32Mb)
Flash Mode: QIO
Partition Scheme: Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS)
Upload Speed: 921600

Find it: Tools ▸ Board ▸ ESP32 Arduino ▸ ESP32H2 Dev Module

blink.ino Copy

// toggle GPIO10 - wire an LED and resistor to it
void setup() {
  pinMode(10, OUTPUT);
}
void loop() {
  digitalWrite(10, HIGH); delay(500);
  digitalWrite(10, LOW);  delay(500);
}

board to selectesp32-h2-devkitm-1⧉ copy

platformio.ini Copy

[env:esp32-h2-super-mini]
platform = https://github.com/pioarduino/platform-espressif32/releases/download/stable/platform-espressif32.zip
board = esp32-h2-devkitm-1
framework = arduino
monitor_speed = 115200
upload_speed = 921600

Find it: PlatformIO Home ▸ Boards, search esp32-h2-devkitm-1 - or type it after board =.

board to selectesp32-h2-devkitm-1⧉ copy

device.yaml Copy

esp32:
  board: esp32-h2-devkitm-1
  variant: esp32h2
  framework:
    type: esp-idf

# blink - GPIO10
output:
  - platform: gpio
    pin: 10
    id: led_out
light:
  - platform: binary
    name: "LED"
    output: led_out

Find it: search ESPHome's board list for esp32-h2-devkitm-1 (same ids as PlatformIO).

esptool doesn't pick board settings - a prebuilt .bin already has them baked in. This is just the raw flash command.

terminal Copy

esptool.py --chip esp32h2 --port /dev/ttyACM0 \
  --baud 921600 write_flash 0x0 firmware.bin

--port = your /dev/tty* (macOS/Linux) or COMx (Windows).

Build details: sketch space 1048576 B · data 262144 B · QIO

Good to know

board-specific quirks worth 60 seconds

There is no WiFi on this board

Read this before buying: unlike every other ESP32, the ESP32-H2 has no WiFi radio at all. What it has instead is Bluetooth 5 LE and an IEEE 802.15.4 radio for Zigbee 3.0, Thread, and Matter-over-Thread. If your project needs to talk to a WiFi network directly, pick the C6 SuperMini - it has all three radios. That's not a flaw, it's the niche: the H2 is built to be a low-power mesh endpoint - a Zigbee sensor, a…

Read this before buying: unlike every other ESP32, the ESP32-H2 has no WiFi radio at all. What it has instead is Bluetooth 5 LE and an IEEE 802.15.4 radio for Zigbee 3.0, Thread, and Matter-over-Thread. If your project needs to talk to a WiFi network directly, pick the C6 SuperMini - it has all three radios.

That's not a flaw, it's the niche: the H2 is built to be a low-power mesh endpoint - a Zigbee sensor, a Thread node - where a border router or hub bridges to your network. Tooling is the same as the C6's 802.15.4 side: ESP-IDF Zigbee/Thread SDKs, Arduino via the standard ESP32 core, and ESPHome's OpenThread support.

No WiFi also means no OTA-over-WiFi, no web dashboards, no MQTT-over-WiFi - plan your architecture around the mesh.

Real measured sleep numbers - power it from the BAT pads

The H2 SuperMini has battery solder pads, and a hands-on measurement on this exact board puts deep sleep at about 0.42 mA when powered through the BAT pads - and roughly 1 mA more via USB, since the USB path keeps extra circuitry awake. Honest framing: 420 µA is far above the H2 chip's own microamp-class sleep spec - board components still leak - but it's an order of magnitude better than classic dev boards, enough…

The H2 SuperMini has battery solder pads, and a hands-on measurement on this exact board puts deep sleep at about 0.42 mA when powered through the BAT pads - and roughly 1 mA more via USB, since the USB path keeps extra circuitry awake.

Honest framing: 420 µA is far above the H2 chip's own microamp-class sleep spec - board components still leak - but it's an order of magnitude better than classic dev boards, enough for weeks-to-months on a small cell depending on wake cadence.

For the lowest draw, power the board from the battery pads and treat USB as a programming connector, not a power strategy.

No USB-serial chip - Serial needs USB CDC

Like the other SuperMinis, the H2 has no USB-to-serial converter chip - USB-C connects straight to the ESP32-H2's native USB. Two everyday consequences: Serial output: enable Tools → USB CDC On Boot → "Enabled" in Arduino IDE, or Serial.print() goes to the UART pins instead of your serial monitor. Flashing: if the COM port never appears or an upload fails, hold BOOT while plugging in USB (or while tapping RESET) to…

Like the other SuperMinis, the H2 has no USB-to-serial converter chip - USB-C connects straight to the ESP32-H2's native USB. Two everyday consequences:

Serial output: enable Tools → USB CDC On Boot → "Enabled" in Arduino IDE, or Serial.print() goes to the UART pins instead of your serial monitor.
Flashing: if the COM port never appears or an upload fails, hold BOOT while plugging in USB (or while tapping RESET) to force the ROM bootloader, then press RESET after flashing.

A crashed or deep-sleeping sketch takes the USB port down with it - normal for native-USB boards, not a broken board. The BOOT-button trick always recovers it.

On-Board LEDs

The ESP32-H2 Supermini features three onboard LEDs: a green battery indicator, a user-controllable blue LED, and a WS2812 RGB LED. Note that the Blue LED and WS2812 share GPIO13 and GPIO8 respectively, and may interfere if both are driven simultaneously due to signal timing constraints. Green LED - Battery Charge Indicator GPIO: None Control: Not controllable via GPIO Behavior: Charging → LED on Battery connected →…

Green LED - Battery Charge Indicator

GPIO: None
Control: Not controllable via GPIO
Behavior:

Charging → LED on
Battery connected → LED off
No battery → LED blinks

Blue LED - User Controllable

GPIO: GPIO13
Control: digitalWrite(), ESPHome GPIO output

Arduino Example:


void setup() {
  pinMode(13, OUTPUT);
}

void loop() {
  digitalWrite(13, HIGH);
  delay(1000);
  digitalWrite(13, LOW);
  delay(1000);
}

ESPHome Example:


output:
  - platform: gpio
    pin: 13
    id: blue_led

light:
  - platform: binary
    name: "Blue LED"
    output: blue_led

ESPHome GPIO Output Documentation →

WS2812 LED - Programmable RGB

GPIO: GPIO8
Control: FastLED, NeoPixel, etc.

Arduino (FastLED) Example:

#include <FastLED.h>

#define NUM_LEDS 1
#define DATA_PIN 8

CRGB leds[NUM_LEDS];

void setup() {
  FastLED.addLeds<NEOPIXEL, DATA_PIN>(leds, NUM_LEDS);
}

void loop() {
  leds[0] = CRGB::Red; FastLED.show(); delay(1000);
  leds[0] = CRGB::Green; FastLED.show(); delay(1000);
  leds[0] = CRGB::Blue; FastLED.show(); delay(1000);

ESPHome (NeoPixelBus) Example:

light:
  - platform: neopixelbus
    type: GRB
    pin: 8
    num_leds: 1
    name: "Onboard RGB LED"

ESPHome NeopixelBus Documentation →

Specifications

ESP32-H2 · 23 × 18 mm · vs other ESP32 chips →

Compute

MCU

ESP32-H2 · RISC-V

Clock

96 MHz

SRAM · Flash

320 KB · 4MB

Radio

Wi-Fi

Bluetooth

5.0 LE

Antenna

Ceramic

I/O

GPIO · ADC

19 · 5

UART · I²C · SPI

2 · 2 · 1

PWM

6 channels

Power

USB

USB-C

Serial

Native (CDC)

Boot address

0x0

Flashing

Upload · OTA

esptool_py · esp_ota

Flash · Boot mode

QIO · QIO

Sketch · Data

1 MB · 256 KB

Dimensions

23 × 18 mm · pin pitch 2.54 mm

The ESP32-H2 Super Mini uses esptool_py for firmware uploads, esp_ota for over-the-air (OTA) updates. Flash mode is QIO with QIO boot mode. The maximum sketch size is 1 MB with 256 KB available for data.

About this board

At 23 × 18 mm it's among the smallest boards in the whole ESP32 family.

Inside sits the ESP32-H2 - a Thread/Zigbee-focused RISC-V with no Wi-Fi at all. Sibling Super Mini boards cover the ESP32-C3, ESP32-C6 and ESP32-S3, so you can change radios or horsepower without changing the footprint.

It's the only ESP32-H2 option in the Super Mini family.

Expect to pay about $5.00 - in line with other Super Mini boards.

Onboard you'll find an addressable RGB LED (GPIO8) and Reset/Boot buttons.

It flashes over native USB - no serial-converter driver needed.

The ESP32-H2 SuperMini is an ultra-low-power IoT development board based on the Espressif ESP32-H2 chip. It features a 32-bit RISC-V single-core processor running at up to 96 MHz. The board integrates IEEE 802.15.4 support, making it compatible with Thread and Zigbee protocols for robust mesh networking. Additionally, it includes Bluetooth Low Energy (BLE) and operates in the 2.4 GHz band with a data rate of up to 250 Kbps. The ESP32-H2 SuperMini is designed for applications requiring low-power consumption, RF stability, and secure wireless communication, making it ideal for IoT, smart home, and industrial automation.

Wondering how the ESP32-H2 SuperMini compares to other SuperMini boards? Check out our full comparison guide to see how it stacks up against the C3, C3 Plus, S3, and C6.

No Wi-Fi radio - 802.15.4 (Thread, Zigbee, Matter) plus Bluetooth LE only
RISC-V 32-bit single-core CPU running at up to 96 MHz
128 KB ROM, 320 KB SRAM, 4 KB Low-Power SRAM
4 MB in-package flash memory (no PSRAM)
Supports IEEE 802.15.4 (Thread and Zigbee)
Bluetooth 5 Low Energy (BLE) support
Operates in the 2.4 GHz band with 250 Kbps data rate
USB Type-C interface for easy programming
Low-power consumption for battery-operated devices

Where to buy

prices are typical street prices

ESP32-H2 Super Mini

$5.00per unit, typical

ALIAliExpress↗

Resources

Board datasheet ae01.alicdn.com↗ ESP32-H2 datasheet espressif.com↗ ESP32-H2-MINI-1 / MINI-1U Datasheet (Espressif) espressif.com↗ESP32-H2-SuperMini board (Zephyr Project documentation) docs.zephyrproject.org↗ESP32-H2 Super Mini hands-on review (AndroidCrypto, Medium) medium.com↗ESP32-H2 Super Mini deep sleep measurements (AndroidCrypto, Medium) medium.com↗

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