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// Copyright 2022 The Pigweed Authors
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.
#pragma once
#include <cstdint>
#include <memory>
#include "pw_bluetooth/low_energy/advertising_data.h"
#include "pw_bluetooth/low_energy/connection.h"
#include "pw_bluetooth/result.h"
#include "pw_bluetooth/types.h"
#include "pw_function/function.h"
#include "pw_status/status.h"
namespace pw::bluetooth::low_energy {
// `AdvertisedPeripheral` instances are valid for the duration of advertising.
class AdvertisedPeripheral {
// Destroying an instance will stop advertising.
virtual ~AdvertisedPeripheral() = default;
// Set a callback that will be called when an error occurs and advertising
// has been stopped (invalidating this object). It is OK to destroy this
// object from within `callback`.
virtual void SetErrorCallback(Closure callback) = 0;
// For connectable advertisements, this callback will be called when an LE
// central connects to the advertisement. It is recommended to set this
// callback immediately after advertising starts to avoid dropping
// connections.
// The returned Connection can be used to interact with the peer. It also
// represents a peripheral's ownership over the connection: the client can
// drop the object to request a disconnection. Similarly, the Connection
// error handler is called by the system to indicate that the connection to
// the peer has been lost. While connections are exclusive among peripherals,
// they may be shared with centrals.
// If advertising is not stopped, this callback may be called with multiple
// connections over the lifetime of an advertisement. It is OK to destroy
// this object from within `callback` in order to stop advertising.
virtual void SetConnectionCallback(
Function<void(std::unique_ptr<Connection>)> callback) = 0;
// Represents the LE Peripheral role, which advertises and is connected to.
class Peripheral {
// The range of the time interval between advertisements. Shorter intervals
// result in faster discovery at the cost of higher power consumption. The
// exact interval used is determined by the Bluetooth controller.
// Time = N * 0.625ms.
// Time range: 0x0020 (20ms) - 0x4000 (10.24s)
struct AdvertisingIntervalRange {
uint16_t min = 0x0800; // 1.28s
uint16_t max = 0x0800; // 1.28s
// Represents the parameters for configuring advertisements.
struct AdvertisingParameters {
// The fields that will be encoded in the data section of advertising
// packets.
AdvertisingData data;
// The fields that are to be sent in a scan response packet. Clients may use
// this to send additional data that does not fit inside an advertising
// packet on platforms that do not support the advertising data length
// extensions.
// If present advertisements will be configured to be scannable.
std::optional<AdvertisingData> scan_response;
// See `AdvertisingIntervalRange` documentation.
AdvertisingIntervalRange interval_range;
// If present, the controller will broadcast connectable advertisements
// which allow peers to initiate connections to the Peripheral. The fields
// of `ConnectionOptions` will configure any connections set up from
// advertising.
std::optional<ConnectionOptions> connection_options;
// Errors returned by `Advertise`.
enum class AdvertiseError {
// The operation or parameters requested are not supported on the current
// hardware.
kNotSupported = 1,
// The provided advertising data exceeds the maximum allowed length when
// encoded.
kAdvertisingDataTooLong = 2,
// The provided scan response data exceeds the maximum allowed length when
// encoded.
kScanResponseDataTooLong = 3,
// The requested parameters are invalid.
kInvalidParameters = 4,
// This may be called if the maximum number of simultaneous advertisements
// has already been reached.
kNotEnoughAdvertisingSlots = 5,
// Advertising could not be initiated due to a hardware or system error.
kFailed = 6,
using AdvertiseCallback = Function<void(
Result<AdvertiseError, std::unique_ptr<AdvertisedPeripheral>>)>;
virtual ~Peripheral() = default;
// Start advertising continuously as a LE peripheral. If advertising cannot
// be initiated then `result_callback` will be called with an error. Once
// started, advertising can be stopped by destroying the returned
// `AdvertisedPeripheral`.
// If the system supports multiple advertising, this may be called as many
// times as there are advertising slots. To reconfigure an advertisement,
// first close the original advertisement and then initiate a new
// advertisement.
// Parameters:
// `parameters` - Parameters used while configuring the advertising
// instance.
// `result_callback` - Called once advertising has started or failed. On
// success, called with an `AdvertisedPeripheral` that models the lifetime
// of the advertisement. Destroying it will stop advertising.
virtual void Advertise(AdvertisingParameters parameters,
AdvertiseCallback&& result_callback) = 0;
} // namespace pw::bluetooth::low_energy