rt-thread_esp-hosted

RT-Thread ESP-Hosted

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The project is licensed under the MIT license as a whole, but contains third-party code under other licenses. Please read carefully the following descriptions of the different license codes.

Overview

The repository has adapted ESP-Hosted-MCU to the RT-Thread system, currently only supports the SPI bus protocol, and uses the 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 chips
• A OTA interface for upgrading ESP firmware

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. Remote Procedure Calls (RPCs), to configure Wi-Fi. For the RPC 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.
• 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 the Using esp-hosted for espressif

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

• Enter Using esp-hosted for espressif menu to configure the ESP-Hoseted:

  --- Using esp-hosted for espressif
  ESP-Hosted Configure  --->
      Select the transport interface (SPI)  --->
      Slave chipset to be used (Slave as ESP32C6)  --->
      [ ] Enable raw throughput transport  ----
      [ ] Enable Transport level packet statistics
      (8) The maximum number of simultaneous sync rpc requests
      (8) The maximum number of simultaneous async rpc requests
      (20) The priority of the esp-hosted rpc thread
      (5120) The stack size of the esp-hosted rpc thread
      (20) The priority of the esp-hosted transport thread
      (1024) The stack size of the esp-hosted SPI thread
      (8) The number for esp-hosted SPI queue
      (esp-hosted) Set the spi device name
      (spi1) Set the spi bus name
      (30000000) Set the maximum spi frequency(Hz)
          Select the pin name or number (Name)  --->
      (PE.7) Set the SPI CS pin name
      (PE.5) Set the data ready pin name
      (PE.6) Set the handshake pin name
      (PE.4) Set the reset pin name
      [*] Use thread initialization
      (2048) The stack size of the init thread
      (20)  The priority of the init thread
  [*] Enable Bluetooth  --->
      Select hci interface (Using vhci device drivers)  --->
      (vhci) The vhci device name
  Wi-Fi Configure  --->
      (40) Max number of WiFi static RX buffers
      (60) Max number of WiFi dynamic RX buffers
      Type of WiFi TX buffers (Dynamic)  --->
      (16) Max number of WiFi cache TX buffers
      (40) Max number of WiFi dynamic TX buffers
      [ ] WiFi CSI(Channel State Information)
      [ ] WiFi AMPDU TX
      [ ] WiFi AMPDU RX
      (752) Max length of WiFi SoftAP Beacon
      (32) WiFi mgmt short buffer number
      [*] Enable WPA3-Personal
      [ ] WiFi FTM
      [*] Power Management for station at disconnected
      [ ] WiFi GCMP Support(GCMP128 and GCMP256)
      [ ] WiFi GMAC Support(GMAC128 and GMAC256)
      (7) Maximum espnow encrypt peers number
      [ ] Enable 802.11R (Fast Transition) Support
  

  ESP-Hosted Configure menu is used to configure the transport interface, slave chipset and transport interface related pins.
  

Select hci interface option is used to select the vhci device driver or NimBLE hci driver for HCI interface.
Selecting vhci device driver will create a character device which will emulate the HCI interface.
Selecting NimBLE hci driver will directly connect to NimBLE stack.

Wi-Fi Configure menu is used to configure the ESP32 Wi-Fi parameters.
WiFi AMPDU TX and WiFi AMPDU RX options are recommended to be disabled, as it is found that enabling them will cause Wi-Fi to drop packets, possibly due to the router not following the standard protocol.

Hardware connections

Signal	ESP32	ESP32-C2/C3/C5/C6	ESP32-S2/S3
CLK	14	6	12
MOSI	13	7	11
MISO	12	2	13
CS	15	10	10
Handshake	26	3	17
Data Ready	4	4	5
Reset In	EN	EN/RST	EN/RST

If you are familiar with esp-idf, you can also try to modify the pins
Or use the Flash Download Tool to burn the firmware corresponding to the chip in the firmware directory.

Build ESP32 firmware

$ cd esp-hosted/slave
$ 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 ESP-Hosted Configuration -> Transport layer -> SPI interface -> select and exit from menuconfig.

• 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

Slave log

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

I (412) NETWORK_ADAPTER: *********************************************************************
I (422) NETWORK_ADAPTER:                 ESP-Hosted-MCU Slave FW version :: 1.0.0
I (432) NETWORK_ADAPTER:                 Transport used :: SPI only
I (442) NETWORK_ADAPTER: *********************************************************************

Host log

you should see following entry in host log:

 \ | /
- RT -     Thread Operating System
 / | \     5.0.2 build Feb 15 2025 09:39:29
 2006 - 2022 Copyright by RT-Thread team
lwIP-2.1.2 initialized!
[4] I/SFUD: Found a Winbond flash chip. Size is 16777216 bytes.
[9] I/SFUD: norflash flash device initialized successfully.
[14] I/SFUD: Probe SPI flash norflash by SPI device spiflash success.
[I/FAL] RT-Thread Flash Abstraction Layer initialize success.
[39] I/sal.skt: Socket Abstraction Layer initialize success.
[I/FAL] The FAL block device (filesystem) created successfully
[154] I/SDIO: SD card capacity 31166976 KB.
found part[0], begin: 2097152, size: 29.738GB
[167] I/filesystem: sd card mount to '/sdcard'
[1265] I/transport: Features supported are:
[1266] I/transport:        - WLAN over SPI
[1269] I/transport:        - HCI over SPI
[1273] I/transport:        - BLE only
[1276] I/transport: Chip is: ESP32c6
[1279] I/vhci.dev: Host BT Support: Enabled
[1283] I/vhci.dev: BT Transport Type: vhci devices
[2387] I/WLAN.dev: wlan init success
[2424] I/WLAN.lwip: eth device init ok name:w0
[2426] I/WLAN.dev: wlan init success
[2444] I/WLAN.lwip: eth device init ok name:w1

Firmware update

ESP-Hosted supports upgrading the ESP32 firmware through the transmission interface.
The upgrade process is as follows:

msh />esp_ota /flash/network_adapter.bin
esp-hosted ota update started
erasing the ota partition..
writing: [==================================================] 100%  1084496 | 100 KB/s
firmware write success!!
slave will restart after 5 sec

The esp_ota command can support either online download or local file as the firmware upgrade package.
The online download method requires the use of the webclient software package:

msh />esp_ota https://file.server.com/network_adapter.bin
esp-hosted ota update started
erasing the ota partition..
writing: [==================================================] 100%  1084496 | 81 KB/s
firmware write success!!
slave will restart after 5 sec
msh />

Supported Chip

CHIP	SDIO	SPI
ESP32	x	*
ESP32-C6	x	o
ESP32-C5	x	*
ESP32-C3	x	o
ESP32-C2	x	o
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
• esp-hosted-mcu
• espressif