RIOT/boards/esp32c3-devkit/doc.txt

/*
 * Copyright (C) 2022 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_esp32c3_devkit ESP32-C3-DevKit Board
 * @ingroup     boards_esp32c3
 * @brief       Support for generic ESP32-C3 boards
 * @author      Gunar Schorcht <gunar@schorcht.net>

\section esp32c3_devkit ESP32-C3-DevKit

## Table of Contents {#esp32c3_devkit_toc}

1. [Overview](#esp32c3_devkit_overview)
2. [Hardware](#esp32c3_devkit_hardware)
    1. [MCU](#esp32c3_devkit_mcu)
    2. [Board Configuration](#esp32c3_devkit_board_configuration)
    3. [Board Pinout](#esp32c3_devkit_pinout)
3. [Flashing the Device](#esp32c3_devkit_flashing)

## Overview {#esp32c3_devkit_overview}

The Espressif ESP32-C3-DevKit boards are a couple of boards that use one of
the following modules:

- ESP32-C3-MINI-1x module (ESP32-C3-DevKitM-1 board)
- ESP32-C3-WROOM-02x module (ESP32-C3-DevKitC-02 board)

Since the number of GPIOs and their possible uses on the ESP32-C3 are quite
limited, the ESP32-C3-DevKit should also work for most other ESP32-C3 boards.
Any modifications required for specific applications could be overridden by
\ref esp32_application_specific_configurations "application-specific board configuration".

\image html "https://docs.espressif.com/projects/esp-idf/en/latest/esp32c3/_images/esp32-c3-devkitm-1-v1-annotated-photo.png" "Espressif ESP32-C3-DevKitM-1" width=800px

[Back to table of contents](#esp32c3_devkit_toc)

## Hardware {#esp32c3_devkit_hardware}

This section describes

- the [MCU](#esp32c3_devkit_mcu),
- the default [board configuration](#esp32c3_devkit_board_configuration),
- [optional hardware configurations](#esp32c3_devkit_optional_hardware),
- the [board pinout](#esp32c3_devkit_pinout).

[Back to table of contents](#esp32c3_devkit_toc)

### MCU {#esp32c3_devkit_mcu}

Most features of the board are provided by the ESP32-C3 SoC. For detailed
information about the ESP32-C3 variant (family) and ESP32x SoCs,
see section \ref esp32_mcu_esp32 "ESP32 SoC Series".

[Back to table of contents](#esp32c3_devkit_toc)

### Board Configuration {#esp32c3_devkit_board_configuration}

ESP32-C3-DevKit boards have no special hardware on board with the exception
of a single pin RGB-LED.

All GPIOs are simply broken out for flexibility. Therefore, the board
configuration is the most flexible one which provides:

- 6 x ADC channels at maximum
- 1 x SPI
- 1 x I2C
- 2 x UART
- 1 RGB-LED

Since all GPIOs have broken out, GPIOs can be used for different purposes
in different applications. For flexibility, GPIOs can be listed in multiple
peripheral configurations, but they can only be used for one peripheral
at a time. For example, GPIO4 is used in the ADC channel definition, the
PWM channel definition and the definition of the SCL signal for I2C_DEV(0).

This is possible because GPIOs are only used for a specific peripheral
interface when either

- the corresponding peripheral module is used, e.g. `periph_i2c` and
  `periph_spi`, or
- the corresponding init function is called, e.g. `adc_init` and
  `pwm_init`.

That is, the purpose for which a GPIO is used depends on which module
or function is used first.

For example, if module `periph_i2c` is not used, the GPIOs listed in I2C
configuration can be used for the other purposes, that is, GPIO4 can be
used as ADC channel or PWM channel.

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>
Function        | GPIOs  | Remarks |Configuration
:---------------|:-------|:--------|:----------------------------------
BUTTON0         | GPIO9  | | |
ADC             | GPIO0, GPIO1, GPIO2, GPIO3, GPIO4, GPIO5 | | see \ref esp32_adc_channels "ADC Channels"
PWM_DEV(0)      | GPIO3, GPIO4 | - | \ref esp32_pwm_channels "PWM Channels"
I2C_DEV(0):SCL  | GPIO4 | | \ref esp32_i2c_interfaces "I2C Interfaces"
I2C_DEV(0):SDA  | GPIO5 | | \ref esp32_i2c_interfaces "I2C Interfaces"
RGB-LED         | GPIO8 | supported by driver module `ws281x` | |
SPI_DEV(0):CLK  | GPIO6 | SPI2_HOST (FSPI) is used | \ref esp32_spi_interfaces "SPI Interfaces"
SPI_DEV(0):MISO | GPIO2 | SPI2_HOST (FSPI) is used | \ref esp32_spi_interfaces "SPI Interfaces"
SPI_DEV(0):MOSI | GPIO7 | SPI2_HOST (FSPI) is used | \ref esp32_spi_interfaces "SPI Interfaces"
SPI_DEV(0):CS0  | GPIO10  | SPI2_HOST (FSPI) is used | \ref esp32_spi_interfaces "SPI Interfaces"
UART_DEV(0):TxD | GPIO21  | Console (configuration is fixed) | \ref esp32_uart_interfaces "UART interfaces"
UART_DEV(0):RxD | GPIO20 | Console (configuration is fixed) | \ref esp32_uart_interfaces "UART interfaces"
</center>
\n
@note The configuration of ADC channels contains all ESP32-C3 GPIOs that could
      be used as ADC channels.

For detailed information about the peripheral configurations of ESP32-C3
boards, see section \ref esp32_peripherals "Common Peripherals".

[Back to table of contents](#esp32c3_devkit_toc)

### Board Pinout {#esp32c3_devkit_pinout}

The following figures show the pinouts as configured by default board
definition.

@image html https://gitlab.com/gschorcht/RIOT.wiki-Images/-/raw/master/esp32/ESP32-C3-DevKitM-1_pinout.png "EPS32-C3-DevKitM-1x Pinout"
@image html https://gitlab.com/gschorcht/RIOT.wiki-Images/-/raw/master/esp32/ESP32-C3-DevKitC-02_pinout.png "EPS32-C3-DevKitC-02x Pinout"

The corresponding board schematics can be found:

- [ESP32-C3-DevKitM-1](https://dl.espressif.com/dl/schematics/SCH_ESP32-C3-DEVKITM-1_V1_20200915A.pdf)
- [ESP32-C3-DevKitC-02](https://dl.espressif.com/dl/schematics/SCH_ESP32-C3-DEVKITC-02_V1_1_20210126A.pdf)

[Back to table of contents](#esp32c3_devkit_toc)

## Flashing the Device {#esp32c3_devkit_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=esp32c3-devkit ...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
For detailed information about ESP32-C3 as well as configuring and compiling
RIOT for ESP32-C3 boards, see \ref esp32_riot.

[Back to table of contents](#esp32c3_devkit_toc)
 */