RIOT/boards/esp32-ethernet-kit-v1_0/doc.txt

/*
 * Copyright (C) 2018 Gunar Schorcht
 * Copyright (C) 2020 Google LLC
 *
 * 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_esp-ethernet-kit-v1_0 ESP32-Ethernet-Kit V1.0 Board
 * @ingroup     boards_esp32_esp-ethernet-kit
 * @brief       Support for for Espressif ESP32-Ethernet-Kit v1.0
 * @author      Gunar Schorcht <gunar@schorcht.net>
 * @author      Erik Ekman <eekman@google.com>

\section esp32-ethernet-kit-v1_0 Espressif ESP32-Ethernet-Kit V1.0

## Table of Contents {#esp32_ethernet_kit_v1_0_toc}

1. [Overview](#esp32_ethernet_kit_v1_0_overview)
2. [Hardware](#esp32_ethernet_kit_v1_0_hardware)
    1. [Board Configuration](#esp32_ethernet_kit_v1_0_board_configuration)
    2. [Board Pinout](#esp32_ethernet_kit_v1_0_pinout)
3. [Other Documentation Resources](#esp32_ethernet_kit_v1_0_other-resources)

## Overview {#esp32_ethernet_kit_v1_0_overview}

The Espressif [ESP32-Ethernet-Kit](https://docs.espressif.com/projects/esp-idf/en/latest/esp32/hw-reference/esp32/get-started-ethernet-kit-v1.0.html) is a development board that uses the ESP32-WROVER-B module. Most important features of the board are

- 100 Mbps Ethernet via IP101G PHY
- USB bridge with JTAG interface

Furthermore, some GPIOs are broken out for extension. The USB bridge based on FDI FT2232HL provides a JTAG interface for OCD debugging through the USB interface.
For flashing and debugging the board, see \ref boards_esp32_esp-ethernet-kit common board documentation.

@image html "https://docs.espressif.com/projects/esp-idf/en/latest/esp32/_images/esp32-ethernet-kit-v1.0.png" "ESP32-Ethernet-Kit V1.0" width=500

[Back to table of contents](#esp32_ethernet_kit_v1_0_toc)

## Hardware {#esp32_ethernet_kit_v1_0_hardware}

This section describes

- the default [board configuration](#esp32_ethernet_kit_v1_0_board_configuration),
- the [board pinout](#esp32_ethernet_kit_v1_0_pinout).

[Back to table of contents](#esp32_ethernet_kit_v1_0_toc)

### Board Configuration {#esp32_ethernet_kit_v1_0_board_configuration}

ESP32-Ethernet-Kit v1.0 has the following on-board components

- 100 Mbps Ethernet via IP101G PHY
- USB bridge with JTAG interface

For detailed information about the configuration of ESP32 boards, see
section Peripherals in \ref esp32_riot.

@note
Only a few GPIOs are broken out and available for external hardware on ESP32-Ethernet-Kit boards. Which GPIOs are available as peripherals depends on used modules.

<center>
Function        | GPIOs  | Remarks |Configuration
:---------------|:-------|:--------|:----------------------------------
BTN0            | GPIO0  | not available if `esp_eth` is used | |
ADC             | GPIO34, GPIO35, GPIO36, GPIO39 | | \ref esp32_adc_channels "ADC Channels"
DAC             | - | | \ref esp32_dac_channels "DAC Channels"
PWM_DEV(0)      | GPIO4 | | \ref esp32_pwm_channels "PWM Channels"
I2C_DEV(0):SDA  | GPIO32 | | \ref esp32_i2c_interfaces "I2C Interfaces"
I2C_DEV(0):SCL  | GPIO33 | | \ref esp32_i2c_interfaces "I2C Interfaces"
SPI_DEV(0):CLK  | GPIO14 | HSPI is used | \ref esp32_spi_interfaces "SPI Interfaces"
SPI_DEV(0):MISO | GPIO12 | HSPI is used | \ref esp32_spi_interfaces "SPI Interfaces"
SPI_DEV(0):MOSI | GPIO13 | HSPI is used | \ref esp32_spi_interfaces "SPI Interfaces"
SPI_DEV(0):CS0  | GPIO15  | HSPI is used | \ref esp32_spi_interfaces "SPI Interfaces"
UART_DEV(0):TxD | GPIO1  | Console (configuration is fixed) | \ref esp32_uart_interfaces "UART interfaces"
UART_DEV(0):RxD | GPIO3  | Console (configuration is fixed) | \ref esp32_uart_interfaces "UART interfaces"
</center>
\n
@note
- GPIO4 only works properly on the board if the function switch
  for GPIO4 (DIP SW 5) is OFF.
- SPI_DEV(0) is not available if module `esp_jtag` is used. For the
  SPI_DEV(0) pins to work properly, the function switches (DIP switches)
  for the JTAG signals must be set to OFF.

[Back to table of contents](#esp32_ethernet_kit_v1_0_toc)

### Board Pinout {#esp32_ethernet_kit_v1_0_pinout}

The board schematic can be found [here](https://dl.espressif.com/dl/schematics/SCH_ESP32-ETHERNET-KIT_A_V1.0_20190517.pdf).

By default, only 3 bidirectional GPIO pins are unused: GPIO4, GPIO32, GPIO33.
The suggested configuration is for PWM and I2C, but they can also be used
for SPI or another serial port. By disabling the JTAG interface on the board,
another 4 GPIOs can be made available (GPIO12, GPIO13, GPIO14, GPIO15).

[Back to table of contents](#esp32_ethernet_kit_v1_0_toc)

## Other Documentation Resources {#esp32_ethernet_kit_v1_0_other-resources}

There is a comprehensive [Getting Started Guide](https://docs.espressif.com/projects/esp-idf/en/latest/esp32/hw-reference/esp32/get-started-ethernet-kit-v1.0.html) for the ESP32-Ethernet-Kit with a lot information about hardware configuration.

[Back to table of contents](#esp32_ethernet_kit_v1_0_toc)
 */