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

<a name="toc"> Table of Contents </a>

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

<a name="overview"> Overview </a>    [<a href="#toc">TOC</a>]

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)

<a name="hardware"> Hardware </a>    [<a href="#toc">TOC</a>]

This section describes

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

<a name="mcu"> MCU </a>    [<a href="#toc">TOC</a>]

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

<a name="board_configuration"> Board Configuration </a>    [<a href="#toc">TOC</a>]

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	SDCARD_CS	on ESP32-EVB available at [UEXT1]	I2C Interfaces
GPIO16	I2C_DEV(0):SCL	I2C_DEV(0):SCL	on ESP32-EVB available at [UEXT1]	I2C Interfaces
GPIO14	SPI_DEV(0):CLK	SDCARD_CLK	on ESP32-EVB available at [UEXT1]	SPI Interfaces
GPIO2	SPI_DEV(0):MISO	SDCARD_MISO	on ESP32-EVB available at [UEXT1]	SPI Interfaces
GPIO15	SPI_DEV(0):MOSI	SDCARD_MOSI	on ESP32-EVB available at [UEXT1]	SPI 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	N/A	ESP32-EVB [UEXT1]	UART 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	N/A	IR is not yet supported
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.

<a name="optional_hardware"> Optional Hardware Configurations </a>    [<a href="#toc">TOC</a>]

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.

<a name="pinout"> Board Pinout </a>    [<a href="#toc">TOC</a>]

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 optional functions in table board configuration.

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

<a name="flashing"> Flashing the Device </a>    [<a href="#toc">TOC</a>]

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 boards.

Files
file	arduino_board.h
	Board specific configuration for the Arduino API.
file	arduino_pinmap.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)