20.2. esp_hosted_wifi_demo

20.2.1. Overview

  • Espressif’s esp-hosted MCU solution enables a host MCU to communicate with ESP32/ESP32-C3 Wi-Fi chips via SPI/SDIO, providing wireless networking capability. This port currently supports only the SPI interface.

  • This example uses FreeRTOS as the real-time operating system and LwIP as the network stack, with CherryShell providing a command-line interface.

  • The port is based on FreeRTOS and LwIP, supporting common Wi-Fi operation commands and network test commands.

  • The reference hardware setup uses Espressif’s ESP32-WROVER-E module (with ESP32 chip) as the Wi-Fi module, connected to the HPMicro host board via SPI.

Main features: - Supports STA/AP/APSTA mode switching - Command support for Wi-Fi scan, connect, disconnect, etc. - Supports DHCP, ping, iperf, and other network functions - Command-line interaction via CherryShell - Adapted to HPMicro SPI driver, with DMA acceleration

20.2.2. CMake Configuration Parameters

This project is built with CMake. Main parameters:

  • CONFIG_FREERTOS: Enable FreeRTOS RTOS (must be enabled)

  • CONFIG_ESP_HOST_MCU: Enable esp-hosted-mcu middleware

  • CONFIG_ESP_HOSTED_SPI: Use SPI as the communication interface between host and ESP chip

  • CONFIG_HPM_SPI: Enable HPMicro platform SPI component

  • CONFIG_DMA_MGR: Enable DMA manager for efficient SPI transfer

  • CONFIG_LWIP: Enable LwIP stack

  • CONFIG_LWIP_DHCP: Enable DHCP client

  • CONFIG_CHERRYSH: Enable CherryShell command line

  • CONFIG_CHERRYSH_INTERFACE: Command line interface type (e.g. uart)

  • configTOTAL_HEAP_SIZE: FreeRTOS heap size (e.g. 61440 bytes)

  • CONFIG_ESP_HOSTED_SPI_GPIO_HANDSHAKE_PIN: SPI handshake pin

  • CONFIG_ESP_HOSTED_SPI_GPIO_DATA_READY_PIN: Data ready pin

  • CONFIG_ESP_HOSTED_SPI_CLOCK_FREQ_MHZ: SPI clock frequency, set to 10MHz in this example. ESP32 SPI slave supports up to 10MHz; adjust according to actual chip capability.

  • CONFIG_ESP_HOSTED_DFLT_TASK_STACK: Stack size for esp-hosted SPI communication and data processing tasks

  • CONFIG_ESP_HOSTED_RPC_TASK_STACK_SIZE: Stack size for esp-hosted RPC listener/handler tasks

  • DCONFIG_ESP_HOSTED_SPI_MODE: SPI mode selection. This example uses mode 2 (CPOL=1, CPHA=0), must match ESP32 firmware.

  • DCONFIG_SLAVE_IDF_TARGET_ESP32： Specify the slave chip type as ESP32. For other models like ESP32-C3, change to the corresponding macro definition DCONFIG_SLAVE_IDF_TARGET_ESP32C3.

See CMakeLists.txt for details.

20.2.3. How to Run the Example

  • Build and flash the program

  • Serial terminal output example:

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$$ |  $$ |$$ |      $$ |\$  /$$ |$$ |$$ |      $$ |      $$ |  $$ |
$$ |  $$ |$$ |      $$ | \_/ $$ |$$ |\$$$$$$$\ $$ |      \$$$$$$  |
\__|  \__|\__|      \__|     \__|\__| \_______|\__|       \______/
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cherry@hpm5301evklite:/$ [I/H_API] I ESP-Hosted starting. Hosted_Tasks: prio:23, stack: 512 RPC_task_stack: 1024

[I/H_API] I ** add_esp_wifi_remote_channels **

[I/transport] I Add ESP-Hosted channel IF[1]: S[0] Tx[80057f10] Rx[8005f7ce]

[I/transport] I Add ESP-Hosted channel IF[2]: S[0] Tx[8003c50c] Rx[8005f7ce]

[I/spi_wrapper] I Transport: SPI, Mode:2 Freq:10MHz TxQ:2000 RxQ:2000
GPIOs: CLK:0 MOSI:0 MISO:0 CS:0 HS:44 DR:45 SlaveReset:9

[I/transport] I Attempt connection with slave: retry[0]

[I/spi] I Resetting slave

[I/spi] I Resetting slave on SPI bus with pin 9

[I/spi] I Staring SPI task

[I/transport] I Waiting for esp_hosted slave to be ready

[I/transport] I Received INIT event from ESP32 peripheral

[I/transport] I EVENT: 12

[I/transport] I Identified slave [esp32]

[I/transport] I EVENT: 11

[I/transport] I capabilities: 0xf8

[I/transport] I Features supported are:

[I/transport] I            - HCI over SPI

[I/transport] I            - BT/BLE dual mode

[I/transport] I EVENT: 13

[I/transport] I ESP board type is : 0


[I/transport] I Base transport is set-up, TRANSPORT_TX_ACTIVE

[I/H_API] I Transport active

[I/transport] I Slave chip Id[12]

[I/transport] I raw_tp_dir[-], flow_ctrl: low[0] high[0]

[I/transport] I transport_delayed_init

[I/spi] I Received INIT event

[I/esp_wlan_ops] I AP started, SSID: hpm_ap_test

[I/RPC_WRAP] I ESP Event: wifi station started

[I/RPC_WRAP] I ESP Event: wifi station started

[I/RPC_WRAP] I ESP Event: softap started

[I/RPC_WRAP] I ESP Event: softap started

[W/rpc_rsp] W Hosted RPC_Resp [0x21a], uid [7], resp code [12298]

20.2.4. Command Line Usage

After power-up, the serial terminal will output startup information. Type help to see all supported commands. Common commands:

  • wifi scan: Scan for nearby Wi-Fi APs

  • wifi join <SSID> <PASSWORD>: Connect to a specified Wi-Fi

  • wifi stop: Disconnect from current Wi-Fi

  • mem: View memory usage

  • thread: View FreeRTOS task info

  • iperf: Network performance test

  • ping <ip/domain>: Network connectivity test

20.2.5. Typical Usage Flow

wifi scan
wifi join MySSID MyPassword
ping 192.168.1.1
iperf -c 192.168.1.100

20.2.6. Porting Notes and Precautions

  • SPI communication parameters must match those on the ESP32 firmware side (mode, clock, pins, etc.).

  • The Wi-Fi module must be flashed with esp-hosted MCU slave firmware.

  • If you encounter connection failures or scan errors, please check hardware wiring and SPI configuration.

20.2.7. References