Historia

morris 16677b0d3c global: make periph enable/disable APIs private peripheral enable/disable usually should be managed by driver itself, so make it as espressif private APIs, not recommended for user to use it in application code. However, if user want to re-write the driver or ports to other platform, this is still possible by including the header in this way: "esp_private/peripheral_ctrl.h"		2021-11-08 10:37:47 +08:00
..
main	global: make periph enable/disable APIs private	2021-11-08 10:37:47 +08:00
CMakeLists.txt	Added example(ESP32-C3), to use Bluetooth Controller through HCI UART transport	2021-04-30 15:25:10 +00:00
README.md	ci: temporarily disable s3 build for a few examples	2021-09-16 12:20:11 +08:00
sdkconfig.defaults	components/bt: Fix link error of Kconfig	2021-09-13 15:45:27 +08:00

README.md

Supported Targets	ESP32-C3

ESP-IDF UART HCI Controller

This example demonstrates how to configure the Bluetooth Low Energy Controller's HCI (Host Controller Interface) to communicate over UART.

Using this example, BLE radio capabilities of ESP32-C3/ESP32-S3 chip, can be:

tested via standard HCI messages in Direct Test Mode
used with external Bluetooth host stack installed on PC, or other MCU.

This example uses UHCI, GDMA together with UART to implement the HCI UART transport.

This example uses LL/register access directly, because the UHCI driver hasn't been implemented yet.

How to use example

Hardware Required

This example should be able to run on any commonly available ESP32-C3/ESP32-S3 development board. To connect UART to PC, another board such as ESP_Test Board or FT232 USB UART board is usually needed.

In this example, two UARTs are used:

UART0 is used as normal output or by IDF monitor
UART1 is used to convey HCI messages

RTS and CTS lines of UART1 are required. GPIO4, GPIO5, GPIO6, GPIO7 are used as TxD, RxD, RTS, CTS PINs of UART1, respectively.

In a frequently-used scenario, if ESP_Test Board is used, connect the TX0, RX0, RTS0, CTS0 and GND of ESP_Test Board to ESP32-C3/ESP32-S3 UART1 PINs, and Attach ESP_Test board to the host PC.

Configure the project

idf.py menuconfig

Baudrate of UART1 can be configured in Example Configuration > UART Baudrate for HCI

Build and Flash

Build the project and flash it to the board, then run monitor tool to view serial output:

idf.py -p PORT flash monitor

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

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

See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.

Example Output

The example sets up the HCI UART transport and enable Bluetooth Controller, after started. UART1 PIN and baudrate settings is printed at serial output:

I (296) gpio: GPIO[4]| InputEn: 0| OutputEn: 1| OpenDrain: 0| Pullup: 0| Pulldown: 0| Intr:0
I (296) gpio: GPIO[6]| InputEn: 0| OutputEn: 1| OpenDrain: 0| Pullup: 0| Pulldown: 0| Intr:0
I (306) gpio: GPIO[4]| InputEn: 1| OutputEn: 0| OpenDrain: 0| Pullup: 0| Pulldown: 0| Intr:0
I (316) gpio: GPIO[6]| InputEn: 1| OutputEn: 0| OpenDrain: 0| Pullup: 0| Pulldown: 0| Intr:0
I (326) BTDM_INIT: BT controller compile version [6ab3130]
I (336) coexist: coexist rom version 8459080
I (336) phy_init: phy_version 500,985899c,Apr 19 2021,16:05:08
I (466) system_api: Base MAC address is not set
I (466) system_api: read default base MAC address from EFUSE
I (476) BTDM_INIT: Bluetooth MAC: 7c:df:a1:40:3f:16

I (476) UHCI: HCI messages can be communicated over UART1:
--PINs: TxD 4, RxD 5, RTS 6, CTS 7
--Baudrate: 921600

After these output occurs, HCI messages can be commnunicated over UART1.