| .. _heltec_wifi_lora32_v2: |
| |
| Heltec WiFi LoRa 32 (V2) |
| ######################## |
| |
| Overview |
| ******** |
| |
| Heltec WiFi LoRa 32 is a classic IoT dev-board designed & produced by Heltec Automation(TM), it’s a highly |
| integrated product based on ESP32 + SX127x, it has Wi-Fi, BLE, LoRa functions, also Li-Po battery management |
| system, 0.96" OLED are also included. [1]_ |
| |
| The features include the following: |
| |
| - Microprocessor: ESP32 (dual-core 32-bit MCU + ULP core) |
| - LoRa node chip SX1276/SX1278 |
| - Micro USB interface with a complete voltage regulator, ESD protection, short circuit protection, |
| RF shielding, and other protection measures |
| - Onboard SH1.25-2 battery interface, integrated lithium battery management system |
| - Integrated WiFi, LoRa, Bluetooth three network connections, onboard Wi-Fi, Bluetooth dedicated 2.4GHz |
| metal 3D antenna, reserved IPEX (U.FL) interface for LoRa use |
| - Onboard 0.96-inch 128*64 dot matrix OLED display |
| - Integrated CP2102 USB to serial port chip |
| |
| System requirements |
| ******************* |
| |
| Prerequisites |
| ============= |
| |
| The ESP32 toolchain :file:`xtensa-esp32-elf` is required to build this port. |
| The toolchain installation can be performed in two ways: |
| |
| #. Automatic installation |
| |
| .. code-block:: console |
| |
| west espressif install |
| |
| .. note:: |
| |
| By default, the toolchain will be downloaded and installed under $HOME/.espressif directory |
| (%USERPROFILE%/.espressif on Windows). |
| |
| #. Manual installation |
| |
| Follow the `ESP32 Toolchain`_ link to download proper OS package version. |
| Unpack the toolchain file to a known location as it will be required for environment path configuration. |
| |
| Build Environment Setup |
| ======================= |
| |
| Some variables must be exported into the environment prior to building this port. |
| Find more information at :ref:`env_vars` on how to keep this settings saved in you environment. |
| |
| .. note:: |
| |
| In case of manual toolchain installation, set :file:`ESPRESSIF_TOOLCHAIN_PATH` accordingly. |
| Otherwise, set toolchain path as below. If necessary, update the version folder path as in :file:`esp-2020r3-8.4.0`. |
| |
| On Linux and macOS: |
| |
| .. code-block:: console |
| |
| export ZEPHYR_TOOLCHAIN_VARIANT="espressif" |
| export ESPRESSIF_TOOLCHAIN_PATH="${HOME}/.espressif/tools/zephyr" |
| |
| On Windows: |
| |
| .. code-block:: console |
| |
| # on CMD: |
| set ESPRESSIF_TOOLCHAIN_PATH=%USERPROFILE%\.espressif\tools\zephyr |
| set ZEPHYR_TOOLCHAIN_VARIANT=espressif |
| |
| # on PowerShell |
| $env:ESPRESSIF_TOOLCHAIN_PATH="$env:USERPROFILE\.espressif\tools\zephyr" |
| $env:ZEPHYR_TOOLCHAIN_VARIANT="espressif" |
| |
| Finally, retrieve required submodules to build this port. This might take a while for the first time: |
| |
| .. code-block:: console |
| |
| west espressif update |
| |
| .. note:: |
| |
| It is recommended running the command above after :file:`west update` so that submodules also get updated. |
| |
| Flashing |
| ======== |
| |
| The usual ``flash`` target will work with the ``heltec_wifi_lora32_v2`` board |
| configuration. Here is an example for the :ref:`hello_world` |
| application. |
| |
| .. zephyr-app-commands:: |
| :zephyr-app: samples/hello_world |
| :board: heltec_wifi_lora32_v2 |
| :goals: flash |
| |
| Refer to :ref:`build_an_application` and :ref:`application_run` 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). It might be necessary to change the flash frequency or the flash |
| mode; please refer to the `esptool documentation`_ for guidance on these |
| settings. |
| |
| All flashing options are now handled by the :ref:`west` tool, including flashing |
| with custom options such as a different serial port. The ``west`` tool supports |
| specific options for the ESP32 board, as listed here: |
| |
| --esp-idf-path ESP_IDF_PATH |
| path to ESP-IDF |
| --esp-device ESP_DEVICE |
| serial port to flash, default $ESPTOOL_PORT if defined. |
| If not, esptool will loop over available serial ports until |
| it finds ESP32 device to flash. |
| --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: |
| |
| |
| .. code-block:: console |
| |
| west flash -d build/ --skip-rebuild --esp-device /dev/ttyUSB2 |
| |
| |
| References |
| ********** |
| |
| .. [1] https://heltec.org/project/wifi-lora-32/ |
| .. _`Heltec WiFi LoRa (v2) Pinout Diagram`: https://resource.heltec.cn/download/WiFi_LoRa_32/WIFI_LoRa_32_V2.pdf |
| .. _`Heltec WiFi LoRa (v2) Schematic Diagrams`: https://resource.heltec.cn/download/WiFi_LoRa_32/V2 |
| .. _`ESP32 Toolchain`: https://docs.espressif.com/projects/esp-idf/en/v4.2/esp32/api-guides/tools/idf-tools.html#xtensa-esp32-elf |
| .. _`esptool documentation`: https://github.com/espressif/esptool/blob/master/README.md |