rt-thread_esp-hosted

RT-Thread ESP-Hosted

Overview

The repository has adapted ESP-Hosted-MCU to the RT-Thread system, currently only supports the SPI bus protocol, and uses the rt_spi_device of RT-Thread for SPI bus operations.

This version of ESP-Hosted provides:

• A standard 802.3 network interface for transmitting and receiving 802.3 frames
• A standard HCI interface over which Bluetooth/BLE is supported
• A control interface to configure and control Wi-Fi on ESP board

ESP-Hosted-MCU solution makes use of host's existing TCP/IP and/or Bluetooth/BLE software stack and hardware peripheral like SPI/SDIO/UART to connect to ESP firmware with very thin layer of software.

Although the project doesn't provide a standard 802.11 interface to the host, it provides a easy way, i.e. control path, to configure Wi-Fi. For the control path between the host and ESP board, ESP-Hosted-MCU makes use of Protobuf, which is a language independent data serialization mechanism.

Details about ESP-Hosted-MCU can be found in the ESP-Hosted README.

Using

Add this repository

• Clone the repository to the packages or libraries directory in the RT-Thread project.
• Because the esp-idf and protobuf-c is a submodule, you will need to clone with the --recursive option.
• In the libraries or packages folder in the RT-Thread project, include Kconfig file for ESP-Hosted in its Kconfig files.

• For example, include ESP-Hosted in the libraries directory:

  menu "External Libraries"
  source "$RTT_DIR/../libraries/rt-thread_esp-hosted/Kconfig"
  endmenu
  

Configure ESP-Hosted

• Use the menuconfig command in the env window

• Select Open Using esp-hosted for espressif

  → External Libraries
   [*] Using esp-hosted for espressif  --->
  

• Enter Using esp-hosted for espressif menu to configure the pin and SPI bus:

  --- Using esp-hosted for espressif
  (8)   The priority of the esp-hosted thread
  (5120) The stack size of the esp-hosted thread
  (20)  The priority of the esp-hosted SPI thread
  (1024) The stack size of the esp-hosted SPI thread
  (2)   The size for esp-hosted SPI queue
  (esp-hosted) Set the spi device name
  (spi1)  Set the spi bus name (NEW)
  (-1)    Set the SPI CS pin
  (30000000) Set the maximum spi frequency(Hz)
  (-1)  Set the data ready pin
  (-1)  Set the handshake pin
  (-1)  Set the reset pin
  [*]   Use thread initialization
  (2048)  The stack size of the init thread
  (20)    The priority of the init thread
  

Hardware connections for ESP32

Function	ESP32 Pin	ESP32-S2/S3	ESP32-C2/C3/C5/C6
MISO	IO19	IO13	IO2
CLK	IO18	IO12	IO6
MOSI	IO23	IO11	IO7
CS	IO5	IO10	IO10
GND	GND	GND	GND
Handshake	IO2	IO2	IO3
Data Ready	IO4	IO4	IO4
Reset ESP	EN	RST	RST

If you are familiar with esp-idf, you can also try to modify the pins

Build ESP32 firmware

Set-up ESP-IDF

If you already have an esp-idf environment, you can skip this Set-up
But I recommend using the release/v5.3 branch because this project uses it

• Install the ESP-IDF using script

  $ cd esp
  $ cmake .
  

• Set-Up the build environment using

  $ . ./esp-idf/export.sh
  # Optionally, You can add alias for this command in ~/.bashrc for later use
  

Configure, Build & Flash ESP firmware

• Set slave chipset environment

  $ cd network_adapter
  $ rm -rf sdkconfig build
  $ idf.py set-target <esp_chipset>
  

  where could be one from "esp32", "esp32s2", "esp32s3", "esp32c2", "esp32c3", "esp32c5", "esp32c6"

• Execute following command to configure the project

  $ idf.py menuconfig
  

• This will open project configuration window. To select SPI transport interface, navigate to Example Configuration -> Transport layer -> SPI interface -> select and exit from menuconfig.

:warning: Skip below step for ESP32-S2/S3/C2/C3/C5/C6. Run for ESP32 only.

• If ESP32 slave, Change SPI controller to VSPI. Please navigate to Example Configuration → SPI Configuration and change value of SPI controller to use to 3

To build and flash the app on ESP peripheral, run

$ idf.py -p <serial_port> build flash

• Collect the firmware log using

  $ idf.py -p <serial_port> monitor
  

Checking the Setup

• Firmware log On successful flashing, you should see following entry in ESP log:

  I (412) NETWORK_ADAPTER: *********************************************************************
  I (422) NETWORK_ADAPTER:                 ESP-Hosted Firmware version :: FG-0.0.6.0.0
  I (432) NETWORK_ADAPTER:                 Transport used :: SPI only
  I (442) NETWORK_ADAPTER: *********************************************************************
  

• Host log you should see following entry in MCU log:

  \ | /
  - RT -     Thread Operating System
  / | \     5.0.2 build Dec 20 2024 10:02:05
  2006 - 2022 Copyright by RT-Thread team
  lwIP-2.1.2 initialized!
  [4] I/SFUD: Found a Winbond flash chip. Size is 16777216 bytes.
  [11] I/SFUD: norflash flash device initialized successfully.
  [17] I/SFUD: Probe SPI flash norflash by SPI device spi40 success.
  [I/FAL] RT-Thread Flash Abstraction Layer initialize success.
  [47] I/sal.skt: Socket Abstraction Layer initialize success.
  [I/FAL] The FAL block device (filesystem) created successfully
  [238] I/SDIO: SD card capacity 31166976 KB.
  found part[0], begin: 16384, size: 29.740GB
  [258] I/filesystem: sd card mount to '/sdcard'
  [907] I/esp.netdev: Chip is: ESP32c3
  [911] I/esp.netdev: Features supported are:
  [917] I/esp.netdev:      * WLAN
  [922] I/esp.netdev:      * BT/BLE
  [926] I/esp.netdev:        - HCI over SPI
  [930] I/esp.netdev:        - BLE only
  [1934] I/WLAN.dev: wlan init success
  [1944] I/WLAN.lwip: eth device init ok name:w0
  [1949] I/WLAN.dev: wlan init success
  [1960] I/WLAN.lwip: eth device init ok name:w1
  msh />[10856] I/WLAN.mgnt: wifi connect success ssid:TP-LINK_86A9
  [11863] I/WLAN.lwip: Got IP address : 192.168.0.105
  [30173] I/ntp: Get local time from NTP server: Fri Dec 20 15:13:16 2024
  

Supported Chip

CHIP	SDIO	SPI
ESP32	x	*
ESP32-C6	x	*
ESP32-C5	x	*
ESP32-C3	x	o
ESP32-C2	x	*
ESP32-S3	x	*
ESP32-S2	x	*

'x' indicates no support
'o' indicates tested and supported
'*' means theoretically supported, but not tested

More information

• esp-hosted
• espressif