ESP32-H2-DevKitM

Overview

ESP32-H2-DevKitM-1 is an entry-level development board based on the ESP32-H2-MINI-1 module, which integrates Bluetooth® Low Energy (LE) and IEEE 802.15.4 connectivity. It features the ESP32-H2 SoC — a 32-bit RISC-V core designed for low-power, secure wireless communication, supporting Bluetooth 5 (LE), Bluetooth Mesh, Thread, Matter, and Zigbee protocols. This module is ideal for a wide range of low-power IoT applications.

For details on getting started, check ESP32-H2-DevKitM-1 [1].

Hardware

ESP32-H2 combines IEEE 802.15.4 connectivity with Bluetooth 5 (LE). The SoC is powered by a single-core, 32-bit RISC-V microcontroller that can be clocked up to 96 MHz. The ESP32-H2 has been designed to ensure low power consumption and security for connected devices. ESP32-H2 has 320 KB of SRAM with 16 KB of Cache, 128 KB of ROM, 4 KB LP of memory, and a built-in 2 MB or 4 MB SiP flash. It has 19 programmable GPIOs with support for ADC, SPI, UART, I2C, I2S, RMT, GDMA and LED PWM.

Most of ESP32-H2-DevKitM-1’s I/O pins are broken out to the pin headers on both sides for easy interfacing. Developers can either connect peripherals with jumper wires or mount the board on a breadboard.

ESP32-H2 main features:

  • RISC-V 32-bit single-core microprocessor

  • 320 KB of internal RAM

  • 4 KB LP Memory

  • Bluetooth LE: Bluetooth 5.3 certified

  • IEEE 802.15.4 (Zigbee and Thread)

  • 19 programmable GPIOs

  • Numerous peripherals (details below)

Digital interfaces:

  • 19x GPIOs

  • 2x UART

  • 2x I2C

  • 1x General-purpose SPI

  • 1x I2S

  • 1x Pulse counter

  • 1x USB Serial/JTAG controller

  • 1x TWAI® controller, compatible with ISO 11898-1 (CAN Specification 2.0)

  • 1x LED PWM controller, up to 6 channels

  • 1x Motor Control PWM (MCPWM)

  • 1x Remote Control peripheral (RMT), with up to 2 TX and 2 RX channels

  • 1x Parallel IO interface (PARLIO)

  • General DMA controller (GDMA), with 3 transmit channels and 3 receive channels

  • Event Task Matrix (ETM)

Analog interfaces:

  • 1x 12-bit SAR ADCs, up to 5 channels

  • 1x Temperature sensor (die)

Timers:

  • 1x 52-bit system timer

  • 2x 54-bit general-purpose timers

  • 3x Watchdog timers

Low Power:

  • Four power modes designed for typical scenarios: Active, Modem-sleep, Light-sleep, Deep-sleep

Security:

  • Secure boot

  • Flash encryption

  • 4-Kbit OTP, up to 1792 bits for users

  • Cryptographic hardware acceleration: (AES-128/256, ECC, HMAC, RSA, SHA, Digital signature, Hash)

  • Random number generator (RNG)

For detailed information, check the datasheet at ESP32-H2 Datasheet [2] or the Technical Reference Manual at ESP32-H2 Technical Reference Manual [3].

Supported Features

The esp32h2_devkitm board supports the hardware features listed below.

on-chip / on-board
Feature integrated in the SoC / present on the board.
2 / 2
Number of instances that are enabled / disabled.
Click on the label to see the first instance of this feature in the board/SoC DTS files.
vnd,foo
Compatible string for the Devicetree binding matching the feature.
Click on the link to view the binding documentation.

esp32h2_devkitm/esp32h2 target

Type

Location

Description

Compatible

CPU

on-chip

Espressif RISC-V CPU1

espressif,riscv

Clock control

on-chip

ESP32 Clock (Power & Clock Controller Module) Module1

espressif,esp32-clock

Counter

on-chip

ESP32 general-purpose timers2

espressif,esp32-timer

on-chip

ESP32 counters2

espressif,esp32-counter

Flash controller

on-chip

ESP32 flash controller1

espressif,esp32-flash-controller

GPIO & Headers

on-chip

ESP32 GPIO controller1

espressif,esp32-gpio

Input

on-board

Group of GPIO-bound input keys1

gpio-keys

Interrupt controller

on-chip

ESP32 Interrupt controller1

espressif,esp32-intc

MTD

on-chip

Flash node1

soc-nv-flash

on-chip

Fixed partitions of a flash (or other non-volatile storage) memory1

fixed-partitions

Pin control

on-chip

ESP32 pin controller1

espressif,esp32-pinctrl

RNG

on-chip

ESP32 TRNG (True Random Number Generator)1

espressif,esp32-trng

Sensors

on-chip

ESP32 temperature sensor1

espressif,esp32-temp

Serial controller

on-chip

ESP32 UART1 1

espressif,esp32-uart

Timer

on-chip

ESP32 System Timer1

espressif,esp32-systimer

Watchdog

on-chip

ESP32 watchdog1 1

espressif,esp32-watchdog

System requirements

Espressif HAL requires Bluetooth binary blobs in order work. Run the command below to retrieve those files.

west blobs fetch hal_espressif

Note

It is recommended running the command above after west update.

Runners

The esp32h2_devkitm board supports the runners and associated west commands listed below.

flash debug debugserver attach rtt
esp32 ✅ (default)
openocd ✅ ✅ (default) ✅ ✅ ✅

Building & Flashing

Simple boot

The board could be loaded using the single binary image, without 2nd stage bootloader. It is the default option when building the application without additional configuration.

Note

Simple boot does not provide any security features nor OTA updates.

MCUboot bootloader

User may choose to use MCUboot bootloader instead. In that case the bootloader must be built (and flashed) at least once.

There are two options to be used when building an application:

  1. Sysbuild

  2. Manual build

Note

User can select the MCUboot bootloader by adding the following line to the board default configuration file.

CONFIG_BOOTLOADER_MCUBOOT=y

Sysbuild

The sysbuild makes possible to build and flash all necessary images needed to bootstrap the board with the ESP32 SoC.

To build the sample application using sysbuild use the command:

west build -b <board> --sysbuild samples/hello_world

By default, the ESP32 sysbuild creates bootloader (MCUboot) and application images. But it can be configured to create other kind of images.

Build directory structure created by sysbuild is different from traditional Zephyr build. Output is structured by the domain subdirectories:

build/
├── hello_world
│   └── zephyr
│       ├── zephyr.elf
│       └── zephyr.bin
├── mcuboot
│    └── zephyr
│       ├── zephyr.elf
│       └── zephyr.bin
└── domains.yaml

Note

With --sysbuild option the bootloader will be re-build and re-flash every time the pristine build is used.

For more information about the system build please read the Sysbuild (System build) documentation.

Manual build

During the development cycle, it is intended to build & flash as quickly possible. For that reason, images can be built one at a time using traditional build.

The instructions following are relevant for both manual build and sysbuild. The only difference is the structure of the build directory.

Note

Remember that bootloader (MCUboot) needs to be flash at least once.

Build and flash applications as usual (see Building an Application and Run an Application for more details).

# From the root of the zephyr repository
west build -b <board> samples/hello_world

The usual flash target will work with the board configuration. Here is an example for the Hello World application.

# From the root of the zephyr repository
west build -b <board> samples/hello_world
west flash

Open the serial monitor using the following command:

west espressif monitor

After the board has automatically reset and booted, you should see the following message in the monitor:

***** Booting Zephyr OS vx.x.x-xxx-gxxxxxxxxxxxx *****
Hello World! <board>

Board variants using Snippets

ESP32 boards can be assembled with different modules using multiple combinations of SPI flash sizes, PSRAM sizes and PSRAM modes. The snippets under snippets/espressif provide a modular way to apply these variations at build time without duplicating board definitions.

The following snippet-based variants are supported:

Snippet name

Description

Flash memory size

flash-4M

Board with 4MB of flash

flash-8M

Board with 8MB of flash

flash-16M

Board with 16MB of flash

flash-32M

Board with 32MB of flash

PSRAM memory size

psram-2M

Board with 2MB of PSRAM

psram-4M

Board with 4MB of PSRAM

psram-8M

Board with 8MB of PSRAM

PSRAM utilization

psram-reloc

Relocate flash to PSRAM

psram-wifi

Wi-Fi buffers in PSRAM

To apply a board variant, use the -S flag with west build:

west build -b <board> -S flash-32M -S psram-4M samples/hello_world

Note: These snippets are applicable to boards with compatible hardware support for the selected flash/PSRAM configuration.

Debugging

OpenOCD

As with much custom hardware, the ESP32 modules require patches to OpenOCD that are not upstreamed yet. Espressif maintains their own fork of the project. The custom OpenOCD can be obtained at OpenOCD for ESP32.

The Zephyr SDK uses a bundled version of OpenOCD by default. You can overwrite that behavior by adding the -DOPENOCD=<path/to/bin/openocd> -DOPENOCD_DEFAULT_PATH=<path/to/openocd/share/openocd/scripts> parameter when building.

Here is an example for building the Hello World application.

# From the root of the zephyr repository
west build -b <board> samples/hello_world -- -DOPENOCD=<path/to/bin/openocd> -DOPENOCD_DEFAULT_PATH=<path/to/openocd/share/openocd/scripts>
west flash

You can debug an application in the usual way. Here is an example for the Hello World application.

# From the root of the zephyr repository
west build -b <board> samples/hello_world
west debug

References