Welcome to BTstack

BTstack is BlueKitchen's implementation of the official Bluetooth stack. It is well suited for small, resource-constraint devices such as 8 or 16 bit embedded systems as it is highly configurable and comes with an ultra small memory footprint.

Targeting a variety of platforms is as simple as providing the necessary UART, CPU, and CLOCK implementations. BTstack is currently capable of connecting to Bluetooth-modules via: (H2) HCI USB, (H4) HCI UART + TI's eHCILL, and (H5) HCI Three-Wire UART.

On smaller embedded systems, a minimal run loop implementation allows to use BTstack without a Real Time OS (RTOS). If a RTOS is already provided, BTstack can be integrated and run as a single thread.

On larger systems, BTstack provides a server that connects to a Bluetooth module. Multiple applications can communicate with this server over different inter-process communication methods. As sockets are used for client/server communication, it's easy to interact via higher-level level languages, e.g. there's already a Java binding for use in desktop environments.

BTstack supports the Central and the Peripheral Role of Bluetooth 5 Low Energy specification incl. LE Secure Connections, LE Data Channels, and LE Data Length Extension. It can be configured to run as either single-mode stack or a dual-mode stack.

BTstack is free for non-commercial use. However, for commercial use, tell us a bit about your project to get a quote.

Documentation: HTML, PDF

Third-party libraries (FOSS): List of used libraries and their licenses

Discussion and Community Support: BTstack Google Group

Supported Protocols and Profiles

Protocols: L2CAP (incl. LE Data Channels), RFCOMM, SDP, BNEP, AVDTP, AVCTP, ATT, SM (incl. LE Secure Connections).

Profiles: A2DP, AVRCP incl. Browsing, GAP, GATT, HFP, HID, HSP, IOP, SPP, PAN, PBAP Client.

GATT Service Servers: Battery, Cycling Power, Cycling Speed and Cadence, Device Information, Scan Parameters, Heart Rate, HID over GATT (HOG), Mesh Provisioning, Mesh Proxy, Nordic SPP, u-Blox SPP.

GATT Service Clients:: Battery, Device Information.

GATT Services are in general easy to implement and require short development time. For more GATT Services please contact us, or follow the implementation guidelines.

Beta Stage: HOGP.

In Development: BLE Mesh and more.

It has been qualified with the Bluetooth SIG (QDID 110883) for GAP 1.1, IOP, HFP 1.7, HSP 1.2, SPP 1.2, PAN 1.0, A2DP 1.3, AVRCP 1.6 profiles and GATT, SM of the Bluetooth Core 5.0 specification. For information on MFi/iAP2 support, please contact us.

Evaluation Platforms

Embedded Platforms:

Build Status	Port	Platform
	esp32	Espressif ESP32 2.4 GHz Wi-Fi and Bluetooth Dual-Mode combo chip using FreeRTOS
	max32630-fthr	MAX32630FTHR ARM Cortex M4F Board with onboard Panasonic PAN1326 module containing TI CC2564B Bluetooth controller
	msp432p401lp-cc256x	TI MSP432P401R LaunchPad with CC2564C Dual-mode Bluetooth® Controller Evaluation Module and EM Adapter BoosterPack with additional 32768Hz quartz oscillator
No build server	renesas-tb-s1ja-cc256x	TB-S1JA Target Board Kit with with Dual-mode Bluetooth® CC2564 evaluation board and EM Adapter BoosterPack with additional 32768Hz quartz oscillator
	samv71-xplained-atwilc3000	SAMV71 Ultra Xplained Ultra evaluation kit with ATWILC3000 SHIELD
	stm32-f4discovery-cc2564b	STM32 F4 Discovery Board with CC256xEM Bluetooth Adapter Kit for ST and CC2564B Dual-mode Bluetooth® Controller Evaluation Module
	stm32-l073rz-nucleo-em9304	EM9304 DVK: STM32 Nucleo development board NUCELO-L73RZ with EM9304 Bluetooth Controller
No build server	stm32-wb55xx-nucleo-freertos	P-NUCLEO-WB55 kit
	wiced-h4	Broadcom/Cypress platforms that support the WICED SDK via H4 UART, e.g. RedBear Duo (BCM43438 A1), Inventek Systems ISM4334x (BCM43438 A1), Inventek Systems ISM4343 (BCM43340)

Other Platforms:

Status	Port	Platform
	libusb	Unix-based system with dedicated USB Bluetooth dongle
No build server	libusb-intel	Unix-based system with Intel Wireless 8260/8265 Controller
	posix-h4	Unix-based system connected to Bluetooth module via H4 over serial port
No build server	posix-h4-da14581	Unix-based system connected to Dialog Semiconductor DA14581 via H4 over serial port
No build server	posix-h4-da14585	Unix-based system connected to Dialog Semiconductor DA14585 via H4 over serial port
No build server	posix-h5	Unix-based system connected to Bluetooth module via H5 over serial port
No build server	qt-h4	Unix- or Win32-based Qt application connected to Bluetooth module via H4 over serial port
No build server	qt-usb	Unix- or Win32-based Qt application with dedicated USB Bluetooth dongle
No build server	windows-h4	Win32-based system connected to Bluetooth module via serial port
No build server	windows-h4-da14585	Win32-based system connected to Dialog Semiconductor DA14585 via H4 over serial port
No build server	windows-winusb	Win32-based system with dedicated USB Bluetooth dongle
No build server	windows-winusb-intel	Win32-based system with Intel Wireless 8260/8265 Controller
No build server	raspi	Raspberry Pi 3 or Raspberry Pi Zero W with built-in BCM4343 Bluetooth/Wifi Controller
	daemon	TCP and Unix domain named socket client-server architecture supporting multiple clients
	java	Java wrapper for daemon
	mtk	daemon for rooted Android devices, based on Mediatek MT65xx processor, Java and C client-server API
	ios	daemon for iOS jailbreak devices, C client-server API
No build server	freertos	FreeRTOS: Run BTstack on a dedicated thread, not thread-safe.

Supported Chipsets

Chipset	Type	HCI Transport	SCO over HCI	BTstack folder	Comment
Atmel ATWILC3000	LE	H4	n.a.	atwilc3000	Firmware size: 60 kB
Broadcom UART	Dual mode	H4, H5	Probably	bcm	Max UART baudrate 2 mbps
Broadcom USB Dongles	Dual mode	USB	Yes	bcm
CSR UART	Dual mode	H4, H5, BCSP	No (didn't work)	csr
CSR USB Dongles	Dual mode	USB	Yes	csr
Cypress CYW20704	Dual mode	H4, H5, USB	Probably	bcm
Cypress CYW20819	Dual mode	H4, H5, USB	Probably	bcm	Keep CTS high during power cycle
Cypress CYW43xxx	Dual mode + Wifi	H4, H5	Don't know	bcm	Bluetooth + Wifi Combo Controller
Cypress PSoC 4	LE	H4	n.a.		HCI Firmware part of PSoC Creator kit examples
Dialog Semiconductor DA14581, DA14585	LE	H4, SPI	n.a.	da14581	Official HCI firmware used
Dialog Semiconductor DA1469x	LE	H4, SPI	n.a		HCI Firmware part of DA1469x SDK
Espressif ESP32	Dual mode	VHCI	Not yet		SoC with Bluetooth and Wifi
EM 9301, 9304	LE	SPI	n.a.	em9301	Custom HCI SPI implementation
Intel Dual Wireless 3165, 8260, 8265	Dual mode	USB	Probably	intel	Firmware size: 400 kB
Nordic nRF	LE	H4	n.a.		Requires custom HCI firmware
Renesas RX23W	LE	H4	n.a.		HCI Firmware part of BTTS
STM STLC2500D	Classic	H4	No (didn't try)	stlc2500d	Custom deep sleep management not supported
STM32-WB5x	LE	VHCI	n.a.		SoC with multi-protocol Radio co-processor
Toshiba TC35661	Dual mode	H4	No	tc3566
TI CC256x, WL183x	Dual mode	H4, H5, eHCILL	Yes	cc256x	Also WL185x, WL187x, and WL189x

More infos on supported chipsets

Source Tree Overview

Path	Description
chipset	Support for individual Bluetooth chipsets
doc	Sources for BTstack documentation
example	Example applications available for all ports
platform	Support for special OSs and/or MCU architectures
port	Complete port for a MCU + Chipset combinations
src	Bluetooth stack implementation
test	Unit and PTS tests
tool	Helper tools for BTstack