ESP32-C3¶
Overview¶
ESP32-C3 is a single-core Wi-Fi and Bluetooth 5 (LE) microcontroller SoC, based on the open-source RISC-V architecture. It strikes the right balance of power, I/O capabilities and security, thus offering the optimal cost-effective solution for connected devices. The availability of Wi-Fi and Bluetooth 5 (LE) connectivity not only makes the device configuration easy, but it also facilitates a variety of use-cases based on dual connectivity. 1
The features include the following:
32-bit core RISC-V microcontroller with a maximum clock speed of 160 MHz
400 KB of internal RAM
802.11b/g/n/e/i
A Bluetooth LE subsystem that supports features of Bluetooth 5 and Bluetooth mesh
Various peripherals:
12-bit ADC with up to 18 channels
TWAI compatible with CAN bus 2.0
Temperature sensor
4x SPI
2x I2S
2x I2C
3x UART
LED PWM with up to 16 channels
Cryptographic hardware acceleration (RNG, ECC, RSA, SHA-2, AES)
System requirements¶
Build Environment Setup¶
Some variables must be exported into the environment prior to building this port. Find more information at Setting Variables on how to keep this settings saved in you environment.
Note
In case of manual toolchain installation, set ESPRESSIF_TOOLCHAIN_PATH accordingly.
Otherwise, set toolchain path as below. If necessary.
On Linux and macOS:
export ZEPHYR_TOOLCHAIN_VARIANT="espressif"
export ESPRESSIF_TOOLCHAIN_PATH="${HOME}/.espressif/tools/riscv32-esp-elf/1.24.0.123_64eb9ff-8.4.0/riscv32-esp-elf"
export PATH=$PATH:$ESPRESSIF_TOOLCHAIN_PATH/bin
On Windows:
# on CMD:
set ESPRESSIF_TOOLCHAIN_PATH=%USERPROFILE%\.espressif\tools\riscv32-esp-elf\1.24.0.123_64eb9ff-8.4.0\riscv32-esp-elf
set ZEPHYR_TOOLCHAIN_VARIANT=espressif
set PATH=%PATH%;%ESPRESSIF_TOOLCHAIN_PATH%\bin
# on PowerShell
$env:ESPRESSIF_TOOLCHAIN_PATH="$env:USERPROFILE\.espressif\tools\riscv32-esp-elf\1.24.0.123_64eb9ff-8.4.0\riscv32-esp-elf"
$env:ZEPHYR_TOOLCHAIN_VARIANT="espressif"
$env:Path += "$env:ESPRESSIF_TOOLCHAIN_PATH\bin"
Finally, retrieve required submodules to build this port. This might take a while for the first time:
west espressif update
Note
It is recommended running the command above after west update so that submodules also get updated.
Flashing¶
The usual flash target will work with the esp32c3_devkitm board
configuration. Here is an example for the Hello World
application.
# From the root of the zephyr repository
west build -b esp32c3_devkitm samples/hello_world
west flash
Refer to Building an Application and Run an Application for more details.
It’s impossible to determine which serial port the ESP32 board is
connected to, as it uses a generic RS232-USB converter. The default of
/dev/ttyUSB0 is provided as that’s often the assigned name on a Linux
machine without any other such converters.
The baud rate of 921600bps is recommended. If experiencing issues when flashing, try halving the value a few times (460800, 230400, 115200, etc).
All flashing options are now handled by the West (Zephyr’s meta-tool) tool, including flashing
with custom options such as a different serial port. The west tool supports
specific options for the ESP32C3 board, as listed here:
- --esp-idf-path ESP_IDF_PATH
path to ESP-IDF
- --esp-device ESP_DEVICE
serial port to flash, default /dev/ttyUSB0
- --esp-baud-rate ESP_BAUD_RATE
serial baud rate, default 921600
- --esp-flash-size ESP_FLASH_SIZE
flash size, default “detect”
- --esp-flash-freq ESP_FLASH_FREQ
flash frequency, default “40m”
- --esp-flash-mode ESP_FLASH_MODE
flash mode, default “dio”
- --esp-tool ESP_TOOL
if given, complete path to espidf. default is to search for it in [ESP_IDF_PATH]/components/esptool_py/ esptool/esptool.py
- --esp-flash-bootloader ESP_FLASH_BOOTLOADER
Bootloader image to flash
- --esp-flash-partition_table ESP_FLASH_PARTITION_TABLE
Partition table to flash
For example, to flash to /dev/ttyUSB2, use the following command after
having build the application in the build directory:
west flash -d build/ --skip-rebuild --esp-device /dev/ttyUSB2