RIOT/boards/seeedstudio-xiao-esp32c3/doc.md

@defgroup boards_seeedstudio-xiao-esp32c3 Seeed Studio Xiao ESP32C3 @ingroup boards_esp32c3 @brief Support for the Seeed Studio Xiao ESP32-C3 board @author David Picard

\section seeedstudio-xiao-esp32c3 Seeed Studio Xiao ESP32C3

Table of Contents

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

Overview

Seeed Studio Xiao ESP32C3 is an IoT mini development board based on the Espressif ESP32-C3 WiFi/Bluetooth dual-mode chip, featuring a single ­core 32-bit RISC-V CPU that operates at up to 160 MHz.

• Wi-Fi
• Bluetooth
• Battery charging chip: Supports lithium battery charge and discharge management
• Memory: 400KB of SRAM, and 4MB of on-board flash memory
• Small size: 21 x 17.8mm
• Ultra-Low Power: Deep sleep power consumption is about 43μA
• Battery charge indicator red LED

@image html https://files.seeedstudio.com/wiki/XIAO_WiFi/board-pic.png "Seeed Studio EPS32-C3 Xiao" width=200pix

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Hardware

This section describes

• the MCU,
• the default board configuration,
• the board pinout.

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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".

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Board Configuration

The Seeed Studio EPS32-C3 Xiao board has a reset button and a bootloader button, but no LED. After reset, the bootloader button may be used by the application.

To select the board, add the following to the make command line:

BOARD=seeedstudio-xiao-esp32c3 make ...

GPIO overview:

• 3 x ADC channels at maximum
• 1 x SPI
• 1 x I2C
• 1 x UART
• 11 x PWM channels (only 4 defined by default)

The purpose for which a GPIO is used depends on which module or function is used first. For example, if module periph_spi is not used, the GPIOs listed in SPI configuration can be used for other purposes.

The following table shows the default board configuration. This configuration can be overridden by \ref esp32_application_specific_configurations "application-specific configurations".

Function | Pin | Configuration :---------------|:----------------------|:------------- BUTTON0 | GPIO9 | GPIO9 is a [strapping pin](https://docs.espressif.com/projects/esptool/en/latest/esp32c3/advanced-topics/boot-mode-selection.html) ADC | GPIO2, GPIO3, GPIO4 | \ref esp32_adc_channels "ADC Channels" I2C_DEV(0):SCL | GPIO7 | \ref esp32_i2c_interfaces "I2C Interfaces" I2C_DEV(0):SDA | GPIO6 | \ref esp32_i2c_interfaces "I2C Interfaces" PWM_DEV(0) | GPIO2, GPIO3, GPIO4, GPIO5 | \ref esp32_pwm_channels "PWM Channels" SPI_DEV(0):SCK | GPIO8 | \ref esp32_spi_interfaces "SPI Interfaces" SPI_DEV(0):MISO | GPIO9 | \ref esp32_spi_interfaces "SPI Interfaces" SPI_DEV(0):MOSI | GPIO10 | \ref esp32_spi_interfaces "SPI Interfaces" SPI_DEV(0):CS0 | GPIO5 | \ref esp32_spi_interfaces "SPI Interfaces" UART_DEV(0):TxD | GPIO21 | \ref esp32_uart_interfaces "UART interfaces" UART_DEV(0):RxD | GPIO20 | \ref esp32_uart_interfaces "UART interfaces" \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".

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Board Pinout

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

@image html https://files.seeedstudio.com/wiki/XIAO_WiFi/pin_map-2.png "Seeed Studio EPS32-C3 Xiao Pinout" width=800

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Board documentation

• schematic (PDF)
• pinout (XLSX)
• ESP32-C3 datasheet (PDF)
• ESP32-C3 Technical Reference Manual (PDF)
• power consumption report (PDF)
• product page
• wiki page

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Flashing the Device

The USB-C connector of the board is directly connected to the USB Serial/JTAG interface of the ESP32-C3 SoC. It can be used to program the board and to debug the application. Just connect the board to your host computer and use the following command:

make flash BOARD=seeedstudio-xiao-esp32c3 ...

The make utility will normally restart the board in download mode in order to flash it. But, on occasion, this reset doesn't work. The programmer can't connect to the board and the flashing operation is aborted with a timeout error:

Serial port /dev/ttyACM0
Connecting...
...
serial.serialutil.SerialTimeoutException: Write timeout

In this situation, restart the board manually in download mode:

1. hold down the BOOT button
2. press and release the RESET button
3. release the BOOT button.

After flashing the board, it will still be in download mode. You have to press the RESET button to start your application.

For detailed information about ESP32-C3 as well as configuring and compiling RIOT for ESP32-C3 boards, see \ref esp32_riot.

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