Bluetoe

Overview

Bluetoe implements a GATT server with a very low memory footprint and a convenience C++ interface. Bluetoe makes easy things easy but gives the opportunity to fiddle with all the low level GATT details if necessary. The main target of Bluetoe is to be implemented on very small microcontrollers. Here is a complete example of a small GATT server, that allows a client to controll an IO pin, running on a nrf51422:

#include <bluetoe/server.hpp>
#include <bluetoe/bindings/nrf51.hpp>
#include <nrf.h>

using namespace bluetoe;

static constexpr int io_pin = 19;

static std::uint8_t io_pin_write_handler( bool state )
{
    // the GPIO pin according to the received value: 0 = off, 1 = on
    NRF_GPIO->OUT = state
        ? NRF_GPIO->OUT | ( 1 << io_pin )
        : NRF_GPIO->OUT & ~( 1 << io_pin );

    return error_codes::success;
}

typedef server<
    service<
        service_uuid< 0xC11169E1, 0x6252, 0x4450, 0x931C, 0x1B43A318783B >,
        characteristic<
            free_write_handler< bool, io_pin_write_handler >
        >
    >
> blinky_server;

blinky_server gatt;

nrf51< blinky_server > gatt_srv;

int main()
{
    // Init GPIO pin
    NRF_GPIO->PIN_CNF[ io_pin ] =
        ( GPIO_PIN_CNF_DRIVE_S0H1 << GPIO_PIN_CNF_DRIVE_Pos ) |
        ( GPIO_PIN_CNF_DIR_Output << GPIO_PIN_CNF_DIR_Pos );

    for ( ;; )
        gatt_srv.run( gatt );
}

Documentation

http://torstenrobitzki.github.io/bluetoe/

L2CAP

Bluetoe ships with its own link layer. Currently a link layer based on the nrf51422 is under construction and is already usable. The link layer implementation will be based and tested on an abstract device, called a scheduled radio and should be easily ported to similar hardware. As Bluetoe is a GATT server implementation, only that parts of the link layer are implemented, that are nessary. Bluetoe can easily adapted to any other existing L2CAP implementation (based on HCI for example).

Current State

The following table show the list of GATT procedures and there implementation status and there planned implementation status:

This is the current state of implemented Advertising Data:

This is the current state of the Link Layer implementation:

Pullrequests are wellcome.

Dependencies

• boost for Unittests
• CMake for build
• a decent C++ compiler supporting C++11