Olimex ESP32-EVB

Support for 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 [TOC]

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: 

1
USEMODULE += olimex_esp32_gateway

Hardware [TOC]

This section describes

MCU [TOC]

Most features of the boards are provided by the ESP32 SoC. The following table summarizes these features and gives an overview of which of these features are supported by RIOT. For detailed information about the ESP32, see section .

MCU ESP32 Supported by RIOT
Vendor Espressif
Cores 1 or 2 x Tensilica Xtensa LX6 1 core
FPU yes (ULP - Ultra low power co-processor) no
RAM 520 kByte SRAM 16 kByte RTC SRAM yes
ROM 520 kByte yes
Flash 512 kByte … 16 MByte yes
Frequency 240 MHz, 160 MHz, 80 MHz yes
Power Consumption 68 mA @ 240 MHz 44 mA @ 160 MHz 31 mA @ 80 MHz 5 uA in deep sleep mode yes yes yes no
Timers 4 x 64 bit yes
ADCs 2 x SAR-ADC with up to 18 x 12 bit channels total yes
DACs 2 x DAC with 8 bit yes
GPIOs 34 (6 of them are only inputs) yes
I2Cs 2 yes
SPIs 4 yes
UARTs 3 yes
WiFi IEEE 802.11 b/g/n built in yes
Bluetooth v4.2 BR/EDR and BLE no
Ethernet MAC interface with dedicated DMA and IEEE 1588 support yes
CAN version 2.0 no
IR up to 8 channels TX/RX no
Motor PWM 2 devices x 6 channels yes
LED PWM 16 channels no
Crypto Hardware acceleration of AES, SHA-2, RSA, ECC, RNG no
Vcc 2.5 - 3.6 V
Documents Datasheet Technical Reference

Board Configuration [TOC]

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 .

Pin Configuration* ESP32-EVB Configuration* ESP32-GATEWAY Remarks / Prerequisites Configuration
GPIO13 i2c.h::I2C_DEV:SDA SDCARD_CS on ESP32-EVB available at [UEXT1]
GPIO16 i2c.h::I2C_DEV:SCL i2c.h::I2C_DEV:SCL on ESP32-EVB available at [UEXT1]
GPIO14 spi.h::SPI_DEV:CLK SDCARD_CLK on ESP32-EVB available at [UEXT1]
GPIO2 spi.h::SPI_DEV:MISO SDCARD_MISO on ESP32-EVB available at [UEXT1]
GPIO15 spi.h::SPI_DEV:MOSI SDCARD_MOSI on ESP32-EVB available at [UEXT1]
GPIO17 spi.h::SPI_DEV:CS0 i2c.h::I2C_DEV:SDA on ESP32-EVB available at [UEXT1]
GPIO1 uart.h::UART_DEV:TxD uart.h::UART_DEV:TxD Console (cannot be changed)
GPIO3 uart.h::UART_DEV:RxD uart.h::UART_DEV:RxD Console (cannot be changed)
GPIO4 uart.h::UART_DEV:TxD N/A ESP32-EVB [UEXT1]
GPIO36 uart.h::UART_DEV:RxD adc.h::ADC_LINE on ESP32-EVB available at [UEXT1]
GPIO32 Relais 1 adc.h::ADC_LINE
GPIO33 Relais 2 LED0
GPIO34 BUTTON0 BUTTON0
GPIO9 pwm.h::PWM_DEV:0 pwm.h::PWM_DEV:0
GPIO10 pwm.h::PWM_DEV:1 pwm.h::PWM_DEV:1
GPIO5 CAN_DEV(0):TX
GPIO35 CAN_DEV(0):RX adc.h::ADC_LINE
GPIO12 IR_DEV(0):TX N/A IR is not yet supported
GPIO39 IR_DEV(0):RX adc.h::ADC_LINE IR is not yet supported
GPIO18 EMAC_SMI:MDIO EMAC_SMI:MDIO LAN interface
GPIO23 EMAC_SMI:MDC EMAC_SMI:MDC LAN interface
GPIO0 EMAC_RMII:TX_CLK EMAC_RMII:TX_CLK LAN interface
GPIO21 EMAC_RMII:TX_EN EMAC_RMII:TX_EN LAN interface
GPIO19 EMAC_RMII:TXD0 EMAC_RMII:TXD0 LAN interface
GPIO22 EMAC_RMII:TXD1 EMAC_RMII:TXD1 LAN interface
GPIO25 EMAC_RMII:RXD0 EMAC_RMII:RXD0 LAN interface
GPIO26 EMAC_RMII:RXD1 EMAC_RMII:RXD1 LAN interface
GPIO27 EMAC_RMII:RX_DV EMAC_RMII:RX_DV LAN interface

Note

  • To use the board configuration for Olimex-ESP32-GATEWAY, it is necessary to add the following line to makefile of the application: 
    1
    USEMODULE += olimex_esp32_gateway
  • GPIO9 and GIOP10 can only be used in dout and dio .
  • It might be necessary to remove the SD card or the peripheral hardware attached to the spi.h::SPI_DEV interface for flashing RIOT. Reason is that the spi.h::SPI_DEV 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 .

Optional Hardware Configurations [TOC]

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

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#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.h::SPI_DEV, 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 ) to keep the configured GPIO free for other purposes.

Board Pinout [TOC]

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 in table board configuration.

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

MCU [TOC]

Most features of the boards are provided by the ESP32 SoC. The following table summarizes these features and gives an overview of which of these features are supported by RIOT. For detailed information about the ESP32, see section .

MCU ESP32 Supported by RIOT
Vendor Espressif
Cores 1 or 2 x Tensilica Xtensa LX6 1 core
FPU yes (ULP - Ultra low power co-processor) no
RAM 520 kByte SRAM 16 kByte RTC SRAM yes
ROM 520 kByte yes
Flash 512 kByte … 16 MByte yes
Frequency 240 MHz, 160 MHz, 80 MHz yes
Power Consumption 68 mA @ 240 MHz 44 mA @ 160 MHz 31 mA @ 80 MHz 5 uA in deep sleep mode yes yes yes no
Timers 4 x 64 bit yes
ADCs 2 x SAR-ADC with up to 18 x 12 bit channels total yes
DACs 2 x DAC with 8 bit yes
GPIOs 34 (6 of them are only inputs) yes
I2Cs 2 yes
SPIs 4 yes
UARTs 3 yes
WiFi IEEE 802.11 b/g/n built in yes
Bluetooth v4.2 BR/EDR and BLE no
Ethernet MAC interface with dedicated DMA and IEEE 1588 support yes
CAN version 2.0 no
IR up to 8 channels TX/RX no
Motor PWM 2 devices x 6 channels yes
LED PWM 16 channels no
Crypto Hardware acceleration of AES, SHA-2, RSA, ECC, RNG no
Vcc 2.5 - 3.6 V
Documents Datasheet Technical Reference

Board Configuration [TOC]

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 .

Pin Configuration* ESP32-EVB Configuration* ESP32-GATEWAY Remarks / Prerequisites Configuration
GPIO13 i2c.h::I2C_DEV:SDA SDCARD_CS on ESP32-EVB available at [UEXT1]
GPIO16 i2c.h::I2C_DEV:SCL i2c.h::I2C_DEV:SCL on ESP32-EVB available at [UEXT1]
GPIO14 spi.h::SPI_DEV:CLK SDCARD_CLK on ESP32-EVB available at [UEXT1]
GPIO2 spi.h::SPI_DEV:MISO SDCARD_MISO on ESP32-EVB available at [UEXT1]
GPIO15 spi.h::SPI_DEV:MOSI SDCARD_MOSI on ESP32-EVB available at [UEXT1]
GPIO17 spi.h::SPI_DEV:CS0 i2c.h::I2C_DEV:SDA on ESP32-EVB available at [UEXT1]
GPIO1 uart.h::UART_DEV:TxD uart.h::UART_DEV:TxD Console (cannot be changed)
GPIO3 uart.h::UART_DEV:RxD uart.h::UART_DEV:RxD Console (cannot be changed)
GPIO4 uart.h::UART_DEV:TxD N/A ESP32-EVB [UEXT1]
GPIO36 uart.h::UART_DEV:RxD adc.h::ADC_LINE on ESP32-EVB available at [UEXT1]
GPIO32 Relais 1 adc.h::ADC_LINE
GPIO33 Relais 2 LED0
GPIO34 BUTTON0 BUTTON0
GPIO9 pwm.h::PWM_DEV:0 pwm.h::PWM_DEV:0
GPIO10 pwm.h::PWM_DEV:1 pwm.h::PWM_DEV:1
GPIO5 CAN_DEV(0):TX
GPIO35 CAN_DEV(0):RX adc.h::ADC_LINE
GPIO12 IR_DEV(0):TX N/A IR is not yet supported
GPIO39 IR_DEV(0):RX adc.h::ADC_LINE IR is not yet supported
GPIO18 EMAC_SMI:MDIO EMAC_SMI:MDIO LAN interface
GPIO23 EMAC_SMI:MDC EMAC_SMI:MDC LAN interface
GPIO0 EMAC_RMII:TX_CLK EMAC_RMII:TX_CLK LAN interface
GPIO21 EMAC_RMII:TX_EN EMAC_RMII:TX_EN LAN interface
GPIO19 EMAC_RMII:TXD0 EMAC_RMII:TXD0 LAN interface
GPIO22 EMAC_RMII:TXD1 EMAC_RMII:TXD1 LAN interface
GPIO25 EMAC_RMII:RXD0 EMAC_RMII:RXD0 LAN interface
GPIO26 EMAC_RMII:RXD1 EMAC_RMII:RXD1 LAN interface
GPIO27 EMAC_RMII:RX_DV EMAC_RMII:RX_DV LAN interface

Note

  • To use the board configuration for Olimex-ESP32-GATEWAY, it is necessary to add the following line to makefile of the application: 
    1
    USEMODULE += olimex_esp32_gateway
  • GPIO9 and GIOP10 can only be used in dout and dio .
  • It might be necessary to remove the SD card or the peripheral hardware attached to the spi.h::SPI_DEV interface for flashing RIOT. Reason is that the spi.h::SPI_DEV 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 .

Optional Hardware Configurations [TOC]

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

1
2
3
4
5
6
7
8
9
#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.h::SPI_DEV, 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 ) to keep the configured GPIO free for other purposes.

Board Pinout [TOC]

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 in table board configuration.

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

Flashing the Device [TOC]

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: 

1
make flash BOARD=esp32-olimex-evb ...
For detailed information about ESP32 as well as configuring and compiling RIOT for ESP32 boards, see .