desklock/firmware/components/esp_hosted/examples/host_bluedroid_host_only

Supported Hosts	ESP32	ESP32-P Series	ESP32-H Series	ESP32-C Series	ESP32-S Series	Any other MCU hosts

Supported Co-Processors	ESP32

ESP-IDF ESP-Hosted Hosted HCI 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 Hosted HCI transport. 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

First, set the host target to ESP32-P4:

idf.py set-target esp32p4

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 host, 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

After setting the host target and configuring the project, 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-].)