rt-thread_esp-hosted/esp-hosted/examples/host_bluedroid_host_only/README.md

Supported Targets	ESP32	ESP32-C2	ESP32-C3	ESP32-C5	ESP32-C6	ESP32-C61	ESP32-H2	ESP32-S3	ESP32-P4	ESP32-H2

ESP-IDF ESP-Hosed VHCI Host

This is a Bluetooth Host using ESP-Hosted as HCI IO to the BT Controller.

Example Layout

This example is modified based on bt_discovery, and all modifications are listed below:

• Removed all dependencies on controller from main.c.

  #include "esp_bt.h"
  
  ...
  
  ESP_ERROR_CHECK(esp_bt_controller_mem_release(ESP_BT_MODE_BLE));
  
  esp_bt_controller_config_t bt_cfg = BT_CONTROLLER_INIT_CONFIG_DEFAULT();
  if ((ret = esp_bt_controller_init(&bt_cfg)) != ESP_OK) {
  ESP_LOGE(GAP_TAG, "%s initialize controller failed: %s", __func__, esp_err_to_name(ret));
  return;
  }
  
  if ((ret = esp_bt_controller_enable(ESP_BT_MODE_CLASSIC_BT)) != ESP_OK) {
  ESP_LOGE(GAP_TAG, "%s enable controller failed: %s", __func__, esp_err_to_name(ret));
  return;
  }
  

• Add support for ESP-Hosted HCI interface: esp_hosted_bt.h.

• Open HCI interface in main.c.

  #include "esp_hosted_bt.h"
  
  ...
  
  /* initialize TRANSPORT first */
  hosted_hci_bluedroid_open();
  
  /* get HCI driver operations */
  esp_bluedroid_hci_driver_operations_t operations = {
  .send = hosted_hci_bluedroid_uart_send,
  .check_send_available = hosted_hci_bluedroid_check_send_available,
  .register_host_callback = hosted_hci_bluedroid_register_host_callback,
  };
  esp_bluedroid_attach_hci_driver(&operations);
  

How to use example

Hardware Required

This example runs on the ESP32-P4 Dev Board connected to a ESP32 via the GPIO header, using SPI FD (full duplex) as ESP-Hosted transport (VHCI). The following GPIO settings were used:

SPI Function	ESP32 GPIO	ESP32-P4 GPIO
MOSI	13	4
MISO	12	5
CLK	14	26
CS	15	6
Handshake	26	20
Data Ready	4	36
Reset	-1	2

[!NOTE] SPI Mode 2 was used on both the ESP32-P4 and ESP32.

Users are free to choose which supported ESP-Hosted transport to use. See the main ESP-Hosted README for a list of supported transports.

For standard HCI, configure the co-processor Bluetooth Controller to use UART as the HCI transport, then select appropriate GPIOs on the ESP32-P4 to configure as a UART. In this mode, ESP-Hosted is not involved in transporting the HCI data.

See the ESP-IDF UART HCI Host example on how to set-up UART for the Bluetooth Host.

Configure the project

For the ESP32 co-processor, run idf.py menuconfig and configure Example Configuration for SPI Full-duplex with the correct SPI mode and GPIOs.

For the ESP32-P4 co-processor, run idf.py menuconfig and under Component config ---> ESP-Hosted config:

• set the transport to be SPI Full-duplex with the correct SPI modem GPIOs (see above table) and SPI Clock frequency (10 MHz max).
• set the Slave chipset used as ESP32.
• set Bluetooth Support ---> Enable Hosted Bluedroid Bluetooth support to enable Bluedroid support. Leave the HCI type as VHCI.

Build and Flash

Build and flash the co-processor and host projects, then run monitor tool to view serial output on both the ESP32 and ESP32-P4:

idf.py -p PORT flash monitor

(Replace PORT with the name of the serial port to use.)

(To exit the serial monitor, type Ctrl-].)