Olimex ESP32-EVB

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:

Supported Features

The olimex_esp32_evb board configuration supports the following hardware features:

Interface	Controller	Driver/Component
EFUSE	on-chip	hwinfo, device ID
FLASH	module	External flash
GPIO	on-chip	gpio
I2C	on-chip	I2C
INTERRUPT	on-chip	interrupt controller
IO_MUX	on-chip	pinctrl
SPI	on-chip	spi
TIMG	on-chip	counter
TRNG	on-chip	entropy
TWAI	on-chip	CAN controller
UART	on-chip	uart
WDT	on-chip	watchdog
WiFi	on-chip	WiFi

The default configuration can be found in the defconfig file: boards/xtensa/olimex_esp32_evb/olimex_esp32_evb_defconfig.

Other hardware features are not currently supported by the port.

System requirements

Prerequisites

Espressif HAL requires binary blobs in order work. The west extension below performs the required syncronization to clone, checkout and pull the submodules:

west espressif update

Note

It is recommended running the command above after west update.

Building & Flashing

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 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 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. Espressif maintains their own fork of the project. The custom OpenOCD can be obtained by running the following extension:

west espressif install

Note

By default, the OpenOCD will be downloaded and installed under $HOME/.espressif/tools/zephyr directory (%USERPROFILE%/.espressif/tools/zephyr on Windows).

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 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 samples/hello_world
west debug