ESP32-EVB

Board Overview

ESP32-EVB

Name:

olimex_esp32_evb

Vendor:

OLIMEX Ltd.

Architecture:

xtensa

SoC:

esp32

Browse board sources

Overview

The Olimex ESP32-EVB is an OSHW certified, open-source IoT board based on the Espressif ESP32-WROOM-32E/UE module. It has a wired 100Mbit/s Ethernet Interface, Bluetooth LE, WiFi, infrared remote control, and CAN connectivity. Two relays allows switching power appliances on and off.

The board can operate from a single LiPo backup battery as it has an internal LiPo battery charger. There is no step-up converter, so relays, CAN, and USB power does not work when running off battery.

Hardware

• ESP32-WROOM-32E/UE module with 4MB flash.

• On-board programmer, CH340T USB-to-UART

• WiFi, Bluetooth LE connectivity.

• 100Mbit/s Ethernet interface, Microchip LAN8710A PHY.

• MicroSD card slot.

• 2 x 10A/250VAC (15A/120VAC 15A/24VDC) relays with connectors and status LEDs.

• CAN interface, Microchip MCP2562-E high-speed CAN transceiver.

• IR receiver and transmitter, up to 5 meters distance.

• BL4054B LiPo battery charger with status LEDs for stand-alone operation during power outages.

• Power jack for external 5VDC power supply.

• Univeral EXTension (UEXT) connector for connecting UEXT modules.

• User push button.

• 40 pin GPIO connector with all ESP32 pins.

For more information about the ESP32-EVB and the ESP32-WROOM-32E/UE module, see these reference documents:

• ESP32-EVB Website [1]

• ESP32-EVB Schematic [2]

• ESP32-EVB GitHub Repository [3]

• ESP32-WROOM32-E/UE Datasheet [4]

Supported Features

The olimex_esp32_evb 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.

olimex_esp32_evb

/

esp32/appcpuesp32/procpu

olimex_esp32_evb/esp32/appcpu target

Type	Location	Description	Compatible
CPU	on-chip	Espressif Xtensa LX6 CPU2	espressif,xtensa-lx6
ADC	on-chip	ESP32 ADC2	espressif,esp32-adc
Bluetooth	on-chip	Bluetooth HCI for Espressif ESP321	espressif,esp32-bt-hci
CAN	on-chip	ESP32 Two-Wire Automotive Interface (TWAI)1	espressif,esp32-twai
Clock control	on-chip	ESP32 RTC (Power & Clock Controller Module) Module1	espressif,esp32-rtc
Counter	on-chip	ESP32 Counter Driver based on RTC Main Timer1	espressif,esp32-rtc-timer
	on-chip	ESP32 general-purpose timers4	espressif,esp32-timer
DAC	on-chip	ESP32 Digital to Analog converter (DAC)1	espressif,esp32-dac
Ethernet	on-chip	ESP32 Ethernet1	espressif,esp32-eth
Flash controller	on-chip	ESP32 flash controller1	espressif,esp32-flash-controller
GPIO & Headers	on-chip	ESP32 GPIO controller2	espressif,esp32-gpio
I2C	on-chip	ESP32 I2C2	espressif,esp32-i2c
Input	on-chip	ESP32 touch sensor input1	espressif,esp32-touch
Interrupt controller	on-chip	ESP32 Interrupt controller1	espressif,esp32-intc
IPM	on-chip	ESP32 soft inter processor message1	espressif,esp32-ipm
Mailbox	on-chip	ESP32 soft mailbox1	espressif,mbox-esp32
MDIO	on-chip	ESP32 MDIO controller1	espressif,esp32-mdio
Memory controller	on-chip	ESP32 pseudo-static RAM controller1	espressif,esp32-psram
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
PWM	on-chip	ESP32 LED Control (LEDC)1	espressif,esp32-ledc
	on-chip	ESP32 Motor Control Pulse Width Modulator (MCPWM)2	espressif,esp32-mcpwm
RNG	on-chip	ESP32 TRNG (True Random Number Generator)1	espressif,esp32-trng
SDHC	on-chip	ESP32 SDHC controller1	espressif,esp32-sdhc
	on-chip	ESP32 SDHC controller slot2	espressif,esp32-sdhc-slot
Sensors	on-chip	ESP32 Pulse Counter (PCNT)1	espressif,esp32-pcnt
Serial controller	on-chip	ESP32 UART3	espressif,esp32-uart
SPI	on-chip	ESP32 SPI2	espressif,esp32-spi
SRAM	on-chip	Generic on-chip SRAM description2	mmio-sram
Watchdog	on-chip	ESP32 watchdog1 1	espressif,esp32-watchdog
Wi-Fi	on-chip	ESP32 SoC Wi-Fi1	espressif,esp32-wifi

olimex_esp32_evb/esp32/procpu target

Type	Location	Description	Compatible
CPU	on-chip	Espressif Xtensa LX6 CPU2	espressif,xtensa-lx6
ADC	on-chip	ESP32 ADC2	espressif,esp32-adc
Bluetooth	on-chip	Bluetooth HCI for Espressif ESP321	espressif,esp32-bt-hci
CAN	on-chip	ESP32 Two-Wire Automotive Interface (TWAI)1	espressif,esp32-twai
Clock control	on-chip	ESP32 RTC (Power & Clock Controller Module) Module1	espressif,esp32-rtc
Counter	on-chip	ESP32 Counter Driver based on RTC Main Timer1	espressif,esp32-rtc-timer
	on-chip	ESP32 general-purpose timers4	espressif,esp32-timer
DAC	on-chip	ESP32 Digital to Analog converter (DAC)1	espressif,esp32-dac
Ethernet	on-chip	ESP32 Ethernet1	espressif,esp32-eth
Flash controller	on-chip	ESP32 flash controller1	espressif,esp32-flash-controller
GPIO & Headers	on-chip	ESP32 GPIO controller2	espressif,esp32-gpio
I2C	on-chip	ESP32 I2C1 1	espressif,esp32-i2c
Input	on-chip	ESP32 touch sensor input1	espressif,esp32-touch
	on-board	Group of GPIO-bound input keys1	gpio-keys
Interrupt controller	on-chip	ESP32 Interrupt controller1	espressif,esp32-intc
IPM	on-chip	ESP32 soft inter processor message1	espressif,esp32-ipm
Mailbox	on-chip	ESP32 soft mailbox1	espressif,mbox-esp32
MDIO	on-chip	ESP32 MDIO controller1	espressif,esp32-mdio
Memory controller	on-chip	ESP32 pseudo-static RAM controller1	espressif,esp32-psram
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
PWM	on-chip	ESP32 LED Control (LEDC)1	espressif,esp32-ledc
	on-chip	ESP32 Motor Control Pulse Width Modulator (MCPWM)2	espressif,esp32-mcpwm
Regulator	on-board	Fixed voltage regulators2	regulator-fixed
RNG	on-chip	ESP32 TRNG (True Random Number Generator)1	espressif,esp32-trng
SDHC	on-chip	ESP32 SDHC controller1	espressif,esp32-sdhc
	on-chip	ESP32 SDHC controller slot2	espressif,esp32-sdhc-slot
Sensors	on-chip	ESP32 Pulse Counter (PCNT)1	espressif,esp32-pcnt
Serial controller	on-chip	ESP32 UART2 1	espressif,esp32-uart
SPI	on-chip	ESP32 SPI1 1	espressif,esp32-spi
SRAM	on-chip	Generic on-chip SRAM description2	mmio-sram
Watchdog	on-chip	ESP32 watchdog1 1	espressif,esp32-watchdog
Wi-Fi	on-chip	ESP32 SoC Wi-Fi1	espressif,esp32-wifi

System requirements

Prerequisites

Espressif HAL requires WiFi and 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.

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 olimex_esp32_evb --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 olimex_esp32_evb/esp32/procpu samples/hello_world

The usual flash target will work with the olimex_esp32_evb board configuration. Here is an example for the Hello World application.

# From the root of the zephyr repository
west build -b olimex_esp32_evb/esp32/procpu 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! olimex_esp32_evb

Debugging

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 ESP32 [5].

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 olimex_esp32_evb/esp32/procpu 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 olimex_esp32_evb/esp32/procpu samples/hello_world
west debug

References

[1]

https://www.olimex.com/Products/IoT/ESP32/ESP32-EVB/open-source-hardware

[2]

https://github.com/OLIMEX/ESP32-EVB/raw/master/HARDWARE/REV-I/ESP32-EVB_Rev_I.pdf

[3]

https://github.com/OLIMEX/ESP32-EVB

[4]

https://www.espressif.com/sites/default/files/documentation/esp32-wroom-32e_esp32-wroom-32ue_datasheet_en.pdf

[5]

https://github.com/espressif/openocd-esp32/releases