Olimex ESP32-EVB

Support for Olimex ESP32-EVB and ESP32-GATEWAY. More...

Detailed Description

Support for Olimex ESP32-EVB and ESP32-GATEWAY.

Author

Gunar Schorcht gunar.nosp@m.@sch.nosp@m.orcht.nosp@m..net

Olimex ESP32-EVB and ESP32-GATEWAY

Table of Contents

1. Overview
2. Hardware
   1. MCU
   2. Board Configuration
   3. Board Pinout
   4. Optional Hardware Configurations
3. Flashing the Device

Overview

Olimex ESP32-EVB and Olimex ESP32-GATEWAY are open source hardware boards which use the ESP32-WROOM module. The key features of the boards are:

• Ethernet LAN interface
• MicroSD card interface
• IR interface (Olimex ESP32-EVB only)
• CAN interface (Olimex ESP32-EVB only)
• two Relais (Olimex ESP32-EVB only)
• UEXT connector with I2C, SPI and UART interfaces (Olimex ESP32-EVB only)

Using the UEXT connector, a lot of off-board hardware modules can be connected to Olimex ESP32-EVB to extend the hardware without the need for soldering iron or breadboards.

Because of the differences in the on-board hardware, it is necessary to add the following line to the makefile of the application to use the according configuration for Olimex ESP32-GATEWAY:

USEMODULE += olimex_esp32_gateway

Olimex ESP32-EVB (left) and Olimex ESP32-GATEWAY (right)

Back to table of contents

Hardware

This section describes

• the MCU,
• the default board configuration,
• optional hardware configurations,
• the board pinout.

Back to table of contents

MCU

Most features of the board are provided by the ESP32 SoC. For detailed information about the ESP32, see section MCU ESP32.

Back to table of contents

Board Configuration

Olimex ESP32-EVB and Olimex ESP32-GATEWAY have the following on-board components:

• Ethernet LAN interface
• MicroSD card interface
• IR interface (Olimex ESP32-EVB only)
• CAN interface (Olimex ESP32-EVB only)
• two Relais (Olimex ESP32-EVB only)
• UEXT connector with I2C, SPI and UART interfaces (Olimex ESP32-EVB only)

The following table shows the default board configuration, which is sorted according to the defined functionality of GPIOs. This configuration can be overridden by application-specific configurations.

Pin	Configuration ESP32-EVB	Configuration ESP32-GATEWAY	Remarks / Prerequisites	Configuration
GPIO13	I2C_DEV(0):SDA	SDMMC_DEV(0):DAT3	on ESP32-EVB available at UEXT1	I2C Interfaces, SDMMC Interfaces
GPIO16	I2C_DEV(0):SCL	I2C_DEV(0):SCL	on ESP32-EVB available at UEXT1	I2C Interfaces
GPIO14	SPI_DEV(0):CLK, SDMMC_DEV(0):CLK	SDMMC_DEV(0):CLK	on ESP32-EVB available at UEXT1	SPI Interfaces, SDMMC Interfaces
GPIO2	SPI_DEV(0):MISO, SDMMC_DEV(0):DAT0	SDMMC_DEV(0):DAT0	on ESP32-EVB available at UEXT1	SPI Interfaces, SDMMC Interfaces
GPIO15	SPI_DEV(0):MOSI, SDMMC_DEV(0):CMD	SDMMC_DEV(0):CMD	on ESP32-EVB available at UEXT1	SPI Interfaces, SDMMC Interfaces
GPIO17	SPI_DEV(0):CS0	I2C_DEV(0):SDA	on ESP32-EVB available at UEXT1	SPI Interfaces
GPIO1	UART_DEV(0):TxD	UART_DEV(0):TxD	Console (cannot be changed)	UART interfaces
GPIO3	UART_DEV(0):RxD	UART_DEV(0):RxD	Console (cannot be changed)	UART interfaces
GPIO4	UART_DEV(1):TxD	SDMMC_DEV(0):DAT1	on ESP32-EVB available at UEXT1	UART interfaces, SDMMC Interfaces
GPIO36	UART_DEV(1):RxD	ADC_LINE(2)	on ESP32-EVB available at UEXT1	UART interfaces
GPIO32	Relais 1	ADC_LINE(0)		ADC Channels
GPIO33	Relais 2	LED0
GPIO34	BUTTON0	BUTTON0
GPIO9	PWM_DEV(0):0	PWM_DEV(0):0		PWM Channels
GPIO10	PWM_DEV(0):1	PWM_DEV(0):1		PWM Channels
GPIO5	CAN_DEV(0):TX			CAN Interfaces
GPIO35	CAN_DEV(0):RX	ADC_LINE(1)		ADC Channels
GPIO12	IR_DEV(0):TX	SDMMC_DEV(0):DAT2	IR is not yet supported	SDMMC Interfaces
GPIO39	IR_DEV(0):RX	ADC_LINE(3)	IR is not yet supported	ADC Channels
GPIO18	EMAC_SMI:MDIO	EMAC_SMI:MDIO	LAN interface	Ethernet MAC
GPIO23	EMAC_SMI:MDC	EMAC_SMI:MDC	LAN interface	Ethernet MAC
GPIO0	EMAC_RMII:TX_CLK	EMAC_RMII:TX_CLK	LAN interface	Ethernet MAC
GPIO21	EMAC_RMII:TX_EN	EMAC_RMII:TX_EN	LAN interface	Ethernet MAC
GPIO19	EMAC_RMII:TXD0	EMAC_RMII:TXD0	LAN interface	Ethernet MAC
GPIO22	EMAC_RMII:TXD1	EMAC_RMII:TXD1	LAN interface	Ethernet MAC
GPIO25	EMAC_RMII:RXD0	EMAC_RMII:RXD0	LAN interface	Ethernet MAC
GPIO26	EMAC_RMII:RXD1	EMAC_RMII:RXD1	LAN interface	Ethernet MAC
GPIO27	EMAC_RMII:RX_DV	EMAC_RMII:RX_DV	LAN interface	Ethernet MAC

Note

To use the board configuration for Olimex-ESP32-GATEWAY, it is necessary to add the following line to makefile of the application:

USEMODULE += olimex_esp32_gateway

• GPIO9 and GIOP10 can only be used in dout and dio flash modes.
• It might be necessary to remove the SD card or the peripheral hardware attached to the SPI_DEV(0) interface for flashing RIOT. Reason is that the SPI_DEV(0) interface uses the HSPI interface with the GPIO2 pin as the MISO signal, which has bootstrapping functionality.

For detailed information about the configuration of ESP32 boards, see section Common Peripherals.

Back to table of contents

Optional Hardware Configurations

MRF24J40-based IEEE 802.15.4 radio modules have been tested with the board. You could use the following code in your application-specific configuration to use such modules:

#ifdef BOARD_ESP32_OLIMEX_EVB && !MODULE_ESP32_OLIMEX_GATEWAY
 
#if MODULE_MRF24J40
#define MRF24J40_PARAM_CS       GPIO9       /* MRF24J40 CS signal    */
#define MRF24J40_PARAM_RESET    GPIO10      /* MRF24J40 RESET signal */
#define MRF24J40_PARAM_INT      GPIO34      /* MRF24J40 INT signal   */
#endif
 
#endif

For other parameters, the default values defined by the drivers can be used.

Note

• Since the Olimex-ESP32-GATEWAY does not break out the GPIO of the HSPI interface SPI_DEV(0), it is not possible to connect such module to Olimex-ESP32-GATEWAY.
• Since the Olimex-ESP32-EVB has a lot of on-board hardware, only a few GPIOs are available for external hardware.
• The RESET signal of MRF24J40 based modules can also be connected to the RST pin of the board (see pinout) to keep the configured GPIO free for other purposes.

Back to table of contents

Board Pinout

The following pictures shows the pinout of Olimex ESP32-EVB and Olimex ESP32-GATEWAY boards as defined by the default board configuration. The light green GPIOs are not used by configured on-board hardware components and can be used for any purpose. However, if optional off-board hardware modules are used, these GPIOs may also be occupied, see section Board Configuration for more information.

The corresponding board schematics can be found on GitHub for Olimex ESP32-EVB board and for Olimex ESP32-GATEWAY.

Olimex ESP32-EVB pinout

Olimex ESP32-GATEWAY pinout

Back to table of contents

Flashing the Device

Flashing RIOT is quite easy. The board has a Micro-USB connector with reset/boot/flash logic. Just connect the board to your host computer and type using the programming port:

make flash BOARD=esp32-olimex-evb ...

For detailed information about ESP32 as well as configuring and compiling RIOT for ESP32 boards, see RIOT-OS on ESP32 SoC Series Boards.

Back to table of contents

Files
file	arduino_iomap.h
	Mapping from MCU pins to Arduino pins.
file	board.h
	Board specific definitions for Olimex ESP32-EVB (ESP32-GATEWAY)
file	gpio_params.h
	Board specific configuration of direct mapped GPIOs.
file	periph_conf.h
	Peripheral MCU configuration for Olimex ESP32-EVB (ESP32-GATEWAY)