/*
 * Copyright (C) 2018 Gunar Schorcht
 *
 * This file is subject to the terms and conditions of the GNU Lesser
 * General Public License v2.1. See the file LICENSE in the top level
 * directory for more details.
 */

/**
 * @defgroup    boards_esp32_olimex-esp32-evb Olimex ESP32-EVB
 * @ingroup     boards_esp32
 * @brief       Support for Olimex ESP32-EVB and ESP32-GATEWAY
 * @author      Gunar Schorcht <gunar@schorcht.net>

\section esp32_olimex-esp32-evb Olimex ESP32-EVB and ESP32-GATEWAY

## Table of Contents {#esp32_olimex_esp32_evb_toc}

1. [Overview](#esp32_olimex_esp32_evb_overview)
2. [Hardware](#esp32_olimex_esp32_evb_hardware)
    1. [MCU](#esp32_olimex_esp32_evb_mcu)
    2. [Board Configuration](#esp32_olimex_esp32_evb_board_configuration)
    3. [Board Pinout](#esp32_olimex_esp32_evb_pinout)
    4. [Optional Hardware Configurations](#esp32_olimex_esp32_evb_optional_hardware)
3. [Flashing the Device](#esp32_olimex_esp32_evb_flashing)

## Overview {#esp32_olimex_esp32_evb_overview}

[Olimex ESP32-EVB](https://github.com/OLIMEX/ESP32-EVB) and
[Olimex ESP32-GATEWAY](https://github.com/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](https://www.olimex.com/Products/Modules/UEXT/) connector with
  I2C, SPI and UART interfaces (Olimex ESP32-EVB only)

Using the UEXT connector, a lot of [off-board hardware modules](https://www.olimex.com/Products/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
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

@image html "https://gitlab.com/gschorcht/RIOT.wiki-Images/raw/master/esp32/Olimex_ESP32-EVB_GATEWAY.png" "Olimex ESP32-EVB (left) and Olimex ESP32-GATEWAY (right)"

[Back to table of contents](#esp32_olimex_esp32_evb_toc)

## Hardware {#esp32_olimex_esp32_evb_hardware}

This section describes

- the [MCU](#esp32_olimex_esp32_evb_mcu),
- the default [board configuration](#esp32_olimex_esp32_evb_board_configuration),
- [optional hardware configurations](#esp32_olimex_esp32_evb_optional_hardware),
- the [board pinout](#esp32_olimex_esp32_evb_pinout).

[Back to table of contents](#esp32_olimex_esp32_evb_toc)

### MCU {#esp32_olimex_esp32_evb_mcu}

Most features of the board are provided by the ESP32 SoC. For detailed
information about the ESP32, see section \ref esp32_mcu_esp32 "MCU ESP32".

[Back to table of contents](#esp32_olimex_esp32_evb_toc)

### Board Configuration {#esp32_olimex_esp32_evb_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](https://www.olimex.com/Products/Modules/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 \ref esp32_application_specific_configurations
"application-specific configurations".

<center>
Pin    | Configuration\n ESP32-EVB | Configuration\n ESP32-GATEWAY | Remarks / Prerequisites | Configuration
:------|:------------------|:-----------------|-|-|
GPIO13 | I2C_DEV(0):SDA    | SDCARD_CS      | on ESP32-EVB available at [UEXT1](https://www.olimex.com/Products/Modules/UEXT) | \ref esp32_i2c_interfaces "I2C Interfaces"
GPIO16 | I2C_DEV(0):SCL    | I2C_DEV(0):SCL   | on ESP32-EVB available at [UEXT1](https://www.olimex.com/Products/Modules/UEXT) | \ref esp32_i2c_interfaces "I2C Interfaces"
GPIO14 | SPI_DEV(0):CLK    | SDCARD_CLK     | on ESP32-EVB available at [UEXT1](https://www.olimex.com/Products/Modules/UEXT) | \ref esp32_spi_interfaces "SPI Interfaces"
GPIO2  | SPI_DEV(0):MISO   | SDCARD_MISO    | on ESP32-EVB available at [UEXT1](https://www.olimex.com/Products/Modules/UEXT) | \ref esp32_spi_interfaces "SPI Interfaces"
GPIO15 | SPI_DEV(0):MOSI   | SDCARD_MOSI    | on ESP32-EVB available at [UEXT1](https://www.olimex.com/Products/Modules/UEXT) | \ref esp32_spi_interfaces "SPI Interfaces"
GPIO17 | SPI_DEV(0):CS0    | I2C_DEV(0):SDA | on ESP32-EVB available at [UEXT1](https://www.olimex.com/Products/Modules/UEXT) | \ref esp32_spi_interfaces "SPI Interfaces"
GPIO1  | UART_DEV(0):TxD   | UART_DEV(0):TxD  | Console (cannot be changed) | \ref esp32_uart_interfaces "UART interfaces"
GPIO3  | UART_DEV(0):RxD   | UART_DEV(0):RxD  | Console (cannot be changed) | \ref esp32_uart_interfaces "UART interfaces"
GPIO4  | UART_DEV(1):TxD   | N/A | on ESP32-EVB available at [UEXT1](https://www.olimex.com/Products/Modules/UEXT) | \ref esp32_uart_interfaces "UART interfaces"
GPIO36 | UART_DEV(1):RxD   | ADC_LINE(2)    | on ESP32-EVB available at [UEXT1](https://www.olimex.com/Products/Modules/UEXT) | \ref esp32_uart_interfaces "UART interfaces"
GPIO32 | Relais 1          | ADC_LINE(0)      | | \ref esp32_adc_channels "ADC Channels"
GPIO33 | Relais 2          | LED0             | | |
GPIO34 | BUTTON0           | BUTTON0          | | |
GPIO9  | PWM_DEV(0):0      | PWM_DEV(0):0     | | \ref esp32_pwm_channels "PWM Channels"
GPIO10 | PWM_DEV(0):1      | PWM_DEV(0):1     | | \ref esp32_pwm_channels "PWM Channels"
GPIO5  | CAN_DEV(0):TX     |                | | \ref esp32_can_interfaces "CAN Interfaces"
GPIO35 | CAN_DEV(0):RX     | ADC_LINE(1)    | | \ref esp32_adc_channels "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 | \ref esp32_adc_channels "ADC Channels"
GPIO18 | EMAC_SMI:MDIO     | EMAC_SMI:MDIO    | LAN interface | \ref esp32_ethernet_network_interface "Ethernet MAC"
GPIO23 | EMAC_SMI:MDC      | EMAC_SMI:MDC     | LAN interface | \ref esp32_ethernet_network_interface "Ethernet MAC"
GPIO0  | EMAC_RMII:TX_CLK  | EMAC_RMII:TX_CLK | LAN interface | \ref esp32_ethernet_network_interface "Ethernet MAC"
GPIO21 | EMAC_RMII:TX_EN   | EMAC_RMII:TX_EN  | LAN interface | \ref esp32_ethernet_network_interface "Ethernet MAC"
GPIO19 | EMAC_RMII:TXD0    | EMAC_RMII:TXD0   | LAN interface | \ref esp32_ethernet_network_interface "Ethernet MAC"
GPIO22 | EMAC_RMII:TXD1    | EMAC_RMII:TXD1   | LAN interface | \ref esp32_ethernet_network_interface "Ethernet MAC"
GPIO25 | EMAC_RMII:RXD0    | EMAC_RMII:RXD0   | LAN interface | \ref esp32_ethernet_network_interface "Ethernet MAC"
GPIO26 | EMAC_RMII:RXD1    | EMAC_RMII:RXD1   | LAN interface | \ref esp32_ethernet_network_interface "Ethernet MAC"
GPIO27 | EMAC_RMII:RX_DV   | EMAC_RMII:RX_DV  | LAN interface | \ref esp32_ethernet_network_interface "Ethernet MAC"
</center>
\n

@note
To use the board configuration for Olimex-ESP32-GATEWAY, it is necessary
to add the following line to makefile of the application:
\n
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
USEMODULE += olimex_esp32_gateway
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- GPIO9 and GIOP10 can only be used in **dout** and **dio**
  \ref esp32_flash_modes "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 \ref esp32_peripherals "Common Peripherals".

[Back to table of contents](#esp32_olimex_esp32_evb_toc)

### Optional Hardware Configurations {#esp32_olimex_esp32_evb_optional_hardware}

MRF24J40-based IEEE 802.15.4 radio modules have been tested with the board.
You could use the following code in your
\ref esp32_application_specific_configurations
"application-specific configuration" to use such modules:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.c}
#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 \ref esp32_olimex_esp32_evb_pinout_img
  "pinout") to keep the configured GPIO free for other purposes.

[Back to table of contents](#esp32_olimex_esp32_evb_toc)

### Board Pinout {#esp32_olimex_esp32_evb_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
\ref esp32_olimex_esp32_evb_board_configuration for more information.

The corresponding board schematics can be found on GitHub for
[Olimex ESP32-EVB board](https://github.com/OLIMEX/ESP32-EVB/raw/master/HARDWARE/REV-D/ESP32-EVB_Rev_D.pdf) and for
[Olimex ESP32-GATEWAY](https://github.com/OLIMEX/ESP32-GATEWAY/raw/master/HARDWARE/Hardware%20revision%20C/ESP32-GATEWAY_Rev_C.pdf).

\anchor esp32_olimex_esp32_evb_pinout_img
@image html "https://gitlab.com/gschorcht/RIOT.wiki-Images/raw/master/esp32/Olimex_ESP32-EVB_pinout.png" "Olimex ESP32-EVB pinout"
@image html "https://gitlab.com/gschorcht/RIOT.wiki-Images/raw/master/esp32/Olimex_ESP32-GATEWAY_pinout.png" "Olimex ESP32-GATEWAY pinout"

[Back to table of contents](#esp32_olimex_esp32_evb_toc)

## Flashing the Device {#esp32_olimex_esp32_evb_flashing}

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 \ref esp32_riot.

[Back to table of contents](#esp32_olimex_esp32_evb_toc)
 */
