BLEServer Class

Properties   Methods   Events   Config Settings   Errors  

An easy-to-use Bluetooth Low Energy (BLE) GATT Server class.

Syntax

BLEServer

Remarks

The BLEServer class provides a simple but flexible BLE GATT server (peripheral) implementation, making it easy to advertise your own services and characteristics, and to respond to the requests of remote BLE GATT clients that connect to them.

Prerequisites

Windows Notes:

Please note that the BLE classes are only supported by Windows 10 Creator's Update (10.0.15063.0) and later.

The Microsoft Visual C++ Redistributable is also required to use IPWorks BLE. A 32-bit program requires the x86 redistributable, and a 64-bit program requires the x64 redistributable. You can download them from Microsoft's website here, under "Other Tools, Frameworks, and Redistributables": https://visualstudio.microsoft.com/downloads/

Android Notes:

The BLE classes require an Android API level of 21 or higher.

Note that on Android, even when pairing is not explicitly enabled in the component, the operating system may automatically perform pairing as it deems appropriate.

iOS/macOS Notes:

The BLE classes have the following operating system requirements:

• iOS 5.0+
• iPadOS 5.0+
• Mac Catalyst 13.0+
• macOS 10.10+

Linux Notes:

On Linux, the BLE classes rely on BlueZ and DBus. These packages must be installed in order to use the components. Many Linux distributions come with BlueZ and DBus pre-installed.

C++ Options:

Additionally note that when using the C++ edition, the project must have the following options (found under Project Settings).

• C/C++ > General > Consume Windows Runtime Extension > Yes(/ZW)
• C/C++ > General > Additional #using Directories > "$(WindowsSdkDir_10)\UnionMetadata\10.0.15063.0;$(VSAPPIDDIR)\VC\vcpackages"
• C/C++ > Code Generation > Enable Minimal Rebuild > No (/GM-)

Adding Services and Characteristics

As with BLEClient, UUIDs may be given as 16-, 32-, or 128-bit hexadecimal strings (a mixture of formats is fine; they're all converted to 128-bit internally).

Props is a bitmask made up of one or more of the following flags:

• 0x0002 (Read): The characteristic's value may be read by clients. Handle the ReadRequested event to supply the value.
• 0x0004 (WriteWithoutResponse): Clients may write the characteristic's value without expecting an acknowledgement.
• 0x0008 (Write): Clients may write the characteristic's value and receive an acknowledgement indicating success or failure.
• 0x0010 (Notify): Clients may subscribe to receive unacknowledged notifications when the characteristic's value changes.
• 0x0020 (Indicate): Clients may subscribe to receive acknowledged indications when the characteristic's value changes.

// Add a simple read-only "Battery Level" characteristic to a "Battery Service". bleserver1.AddCharacteristic("180F", "2A19", 0x0002);

Refer to AddCharacteristic for more detailed information.

Advertising

You can check whether a particular service is currently being advertised by setting the ServiceId property to its UUID, and then inspecting the Listening property. Call StopListening to stop advertising a service.

// AdvertisementStatusChanged event handler. bleserver1.OnAdvertisementStatusChanged += (s, e) => Console.WriteLine("Advertising status: " + e.Status); bleserver1.StartListening("180F"); // ... bleserver1.StopListening("180F");

Handling Client Requests

Handle the ReadRequested event to respond to read requests for characteristics that have the Read flag set. Set the event's ResponseValue parameter to a hex-encoded string holding the bytes to return, and leave its Accept parameter set to its default value of True. To reject the request instead, set Accept to False.

bleserver1.OnReadRequested += (s, e) => { if (e.CharacteristicId.Equals("00002A19-0000-1000-8000-00805F9B34FB", StringComparison.OrdinalIgnoreCase)) { e.ResponseValue = "5A"; // 90 (%), as a single hex-encoded byte. } else { e.Accept = false; } };

Similarly, handle the WriteRequested event to respond to write requests for characteristics that have the Write or WriteWithoutResponse flag set. Its Value parameter holds the hex-encoded string of bytes the client wants to write, and WithResponse indicates whether the client is expecting an acknowledgement. Set Accept to False to reject a write made with acknowledgement; Accept has no effect on writes made without acknowledgement, since the client isn't told the outcome either way.

bleserver1.OnWriteRequested += (s, e) => { Console.WriteLine("Client wrote: " + e.Value); };

Handle the SubscriptionChanged event to know when a Notify or Indicate characteristic gains or loses subscribed clients, and the SessionStatusChanged and Disconnected events to track a client's connection over time.

Once a client has subscribed to a Notify or Indicate characteristic, call UpdateValue whenever its value changes to push the new value to every currently subscribed client. If no clients are currently subscribed, calling UpdateValue has no effect.

// Push a new value to all clients subscribed to notifications/indications on this characteristic. bleserver1.UpdateValue("180F", "2A19", new byte[] { 0x5A });

Usage Notes

Most platforms will in some way limit the use of Bluetooth APIs when your application is in the background. Be aware of the limitations your platform places on the usage of BLE APIs while in the background, and be ready to act accordingly.

Be sure to call StopListening for each of your services when you're finished advertising them.

Property List

The following is the full list of the properties of the class with short descriptions. Click on the links for further details.

Method List

The following is the full list of the methods of the class with short descriptions. Click on the links for further details.

Event List

The following is the full list of the events fired by the class with short descriptions. Click on the links for further details.

Config Settings

The following is a list of config settings for the class with short descriptions. Click on the links for further details.

Characteristics Property (BLEServer Class)

The GATT characteristics which have been added to the server.

Syntax

• C++
• C
• Qt

IPWorksBLEList<IPWorksBLEServerCharacteristic>* GetCharacteristics();

int ipworksble_bleserver_getcharacteristiccount(void* lpObj);

int ipworksble_bleserver_getcharacteristiccansubscribe(void* lpObj, int characteristicindex);

int ipworksble_bleserver_getcharacteristicflags(void* lpObj, int characteristicindex);

char* ipworksble_bleserver_getcharacteristicid(void* lpObj, int characteristicindex);

char* ipworksble_bleserver_getcharacteristicserviceid(void* lpObj, int characteristicindex);

char* ipworksble_bleserver_getcharacteristicuuid(void* lpObj, int characteristicindex);

int getCharacteristicCount();

bool getCharacteristicCanSubscribe(int iCharacteristicIndex);

int getCharacteristicFlags(int iCharacteristicIndex);

QString getCharacteristicId(int iCharacteristicIndex);

QString getCharacteristicServiceId(int iCharacteristicIndex);

QString getCharacteristicUuid(int iCharacteristicIndex);

Remarks

The GATT characteristics which have been added to the server through calls to the AddCharacteristic method. This collection is read-only.

This property is read-only and not available at design time.

Data Type

IPWorksBLEServerCharacteristic

Listening Property (BLEServer Class)

Whether the service identified by ServiceId is currently being advertised.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetListening();

Unicode (Windows)
BOOL GetListening();

int ipworksble_bleserver_getlistening(void* lpObj);

bool getListening();

Default Value

FALSE

Remarks

This property indicates whether the service identified by the ServiceId property is currently being advertised, and can therefore be discovered by remote clients.

Use the StartListening and StopListening methods to start and stop advertising a service.

This property is read-only and not available at design time.

Data Type

Boolean

ServiceId Property (BLEServer Class)

The Id of the service to check the listening status of.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
char* GetServiceId();
int SetServiceId(const char* lpszServiceId);

Unicode (Windows)
LPWSTR GetServiceId();
INT SetServiceId(LPCWSTR lpszServiceId);

char* ipworksble_bleserver_getserviceid(void* lpObj);
int ipworksble_bleserver_setserviceid(void* lpObj, const char* lpszServiceId);

QString getServiceId();
int setServiceId(QString qsServiceId);

Default Value

""

Remarks

Set ServiceId to the Id of a service you've added characteristics to (via AddCharacteristic) in order to inspect its advertising status using the Listening property.

Services are identified by the same UUID string passed to AddCharacteristic, StartListening, and StopListening.

This property is not available at design time.

Data Type

String

Services Property (BLEServer Class)

The GATT services which have been added to the server.

Syntax

• C++
• C
• Qt

IPWorksBLEList<IPWorksBLEServerService>* GetServices();

int ipworksble_bleserver_getservicecount(void* lpObj);

char* ipworksble_bleserver_getserviceinstanceid(void* lpObj, int serviceindex);

char* ipworksble_bleserver_getserviceuuid(void* lpObj, int serviceindex);

int getServiceCount();

QString getServiceInstanceId(int iServiceIndex);

QString getServiceUuid(int iServiceIndex);

Remarks

The GATT services which have been added to the server through calls to the AddCharacteristic method. This collection is read-only.

This property is read-only and not available at design time.

Data Type

IPWorksBLEServerService

AddCharacteristic Method (BLEServer Class)

Adds a characteristic to a service, creating the service if necessary.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int AddCharacteristic(const char* lpszServiceId, const char* lpszCharacteristicId, int iProps);

Unicode (Windows)
INT AddCharacteristic(LPCWSTR lpszServiceId, LPCWSTR lpszCharacteristicId, INT iProps);

int ipworksble_bleserver_addcharacteristic(void* lpObj, const char* lpszServiceId, const char* lpszCharacteristicId, int iProps);

int addCharacteristic(const QString& qsServiceId, const QString& qsCharacteristicId, int iProps);

Remarks

This method adds a characteristic, identified by CharacteristicId, to the service identified by ServiceId. If no service with that Id has been added yet, it is created automatically.

ServiceId and CharacteristicId are UUID strings, and may be specified using 16-, 32-, or 128-bit hexadecimal notation (dashes are optional); they are converted to full 128-bit UUIDs internally.

Props is a bitmask describing the operations remote clients are permitted to perform on the characteristic once it starts being advertised. It should be one or more of the following flags, combined with a bitwise OR:

A characteristic cannot be added to a service that is already being advertised (see StartListening); doing so will cause the class to fails with an error. Once a service has started listening, its set of characteristics is fixed until you call StopListening.

// Add a read-only "Battery Level" characteristic to a "Battery Service". bleserver1.AddCharacteristic("180F", "2A19", 0x0002); // Add a write-only "Alert Level" characteristic to an "Immediate Alert" service. bleserver1.AddCharacteristic("1802", "2A06", 0x0008);

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Config Method (BLEServer Class)

Sets or retrieves a configuration setting.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
char* Config(const char* lpszConfigurationString);

Unicode (Windows)
LPWSTR Config(LPCWSTR lpszConfigurationString);

char* ipworksble_bleserver_config(void* lpObj, const char* lpszConfigurationString);

QString config(const QString& qsConfigurationString);

Remarks

Config is a generic method available in every class. It is used to set and retrieve configuration settings for the class.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

Error Handling (C++)

This method returns a String value ; after it returns, call the GetLastErrorCode() method to obtain its result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message.

DoEvents Method (BLEServer Class)

This method processes events from the internal message queue.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int DoEvents();

Unicode (Windows)
INT DoEvents();

int ipworksble_bleserver_doevents(void* lpObj);

int doEvents();

Remarks

When DoEvents is called, the class processes any available events. If no events are available, it waits for a preset period of time, and then returns.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

StartListening Method (BLEServer Class)

Begins advertising a service so that remote clients can discover and connect to it.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int StartListening(const char* lpszServiceId);

Unicode (Windows)
INT StartListening(LPCWSTR lpszServiceId);

int ipworksble_bleserver_startlistening(void* lpObj, const char* lpszServiceId);

int startListening(const QString& qsServiceId);

Remarks

This method begins advertising the service identified by ServiceId, making it discoverable by nearby GATT clients. ServiceId must identify a service that characteristics have already been added to via AddCharacteristic.

The AdvertisementStatusChanged event fires once advertising actually starts (and again if it later stops or is aborted). You can check whether a service is currently being advertised at any time by setting the ServiceId property to its Id and inspecting the Listening property.

Calling this method for a service that doesn't exist, or that is already being advertised, will cause the class to fails with an error.

bleserver1.AddCharacteristic("180F", "2A19", 0x0002); bleserver1.StartListening("180F");

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

StopListening Method (BLEServer Class)

Stops advertising a service.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int StopListening(const char* lpszServiceId);

Unicode (Windows)
INT StopListening(LPCWSTR lpszServiceId);

int ipworksble_bleserver_stoplistening(void* lpObj, const char* lpszServiceId);

int stopListening(const QString& qsServiceId);

Remarks

This method stops advertising the service identified by ServiceId.

The AdvertisementStatusChanged event fires once advertising has actually stopped.

Calling this method for a service that doesn't exist, or that isn't currently being advertised, will cause the class to fails with an error.

bleserver1.StopListening("180F");

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

UpdateValue Method (BLEServer Class)

Updates the value of a characteristic and sends a notification or indication to all currently subscribed clients.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int UpdateValue(const char* lpszServiceId, const char* lpszCharacteristicId, const char* lpValue, int lenValue);

Unicode (Windows)
INT UpdateValue(LPCWSTR lpszServiceId, LPCWSTR lpszCharacteristicId, LPCSTR lpValue, INT lenValue);

int ipworksble_bleserver_updatevalue(void* lpObj, const char* lpszServiceId, const char* lpszCharacteristicId, const char* lpValue, int lenValue);

int updateValue(const QString& qsServiceId, const QString& qsCharacteristicId, QByteArray& qbaValue);

Remarks

This method broadcasts a value to all subscribed clients. It does not target a specific client.

The value is specified as a byte array. The characteristic must support notifications or indications. If no clients are subscribed, no notification is sent.

Calling this method for a service that is not currently being advertised will cause the class to fails with an error.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

AdvertisementStatusChanged Event (BLEServer Class)

Fired when the advertising status of a service changes.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireAdvertisementStatusChanged(BLEServerAdvertisementStatusChangedEventParams *e);

typedef struct {
  int Status;
  int Error;
  int reserved;
} BLEServerAdvertisementStatusChangedEventParams;


Unicode (Windows)
virtual INT FireAdvertisementStatusChanged(BLEServerAdvertisementStatusChangedEventParams *e);

typedef struct {
  INT Status;
  INT Error;
  INT reserved;
} BLEServerAdvertisementStatusChangedEventParams;

#define EID_BLESERVER_ADVERTISEMENTSTATUSCHANGED 1

virtual INT IPWORKSBLE_CALL FireAdvertisementStatusChanged(int &iStatus, int &iError);

class BLEServerAdvertisementStatusChangedEventParams {
public:
  int status();

  int error();

  int eventRetVal();
  void setEventRetVal(int iRetVal);
};

// To handle, subclass BLEServer and override this emitter function.
virtual int fireAdvertisementStatusChanged(BLEServerAdvertisementStatusChangedEventParams *e) {...}
// Or, connect one or more slots to this signal.
void advertisementStatusChanged(BLEServerAdvertisementStatusChangedEventParams *e);

Remarks

This event fires in response to StartListening and StopListening, and also if advertising is unexpectedly aborted by the underlying Bluetooth stack (for example, because the adapter was disabled).

Status indicates whether advertising has started, stopped, or was aborted; Error holds the underlying Bluetooth-stack error code if Status indicates an abort, or 0 otherwise. The exact numeric values used for Status are platform-dependent.

Note that this event does not identify which service's advertising status has changed. If you are advertising more than one service at a time, set the ServiceId property to each of your service Ids in turn and check the Listening property to determine which one this event pertains to.

Connected Event (BLEServer Class)

Fired when a remote client connects.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireConnected(BLEServerConnectedEventParams *e);

typedef struct {
  const char* ClientId;
  int StatusCode;
  const char* Description;
  int reserved;
} BLEServerConnectedEventParams;


Unicode (Windows)
virtual INT FireConnected(BLEServerConnectedEventParams *e);

typedef struct {
  LPCWSTR ClientId;
  INT StatusCode;
  LPCWSTR Description;
  INT reserved;
} BLEServerConnectedEventParams;

#define EID_BLESERVER_CONNECTED 2

virtual INT IPWORKSBLE_CALL FireConnected(char* &lpszClientId, int &iStatusCode, char* &lpszDescription);

class BLEServerConnectedEventParams {
public:
  const QString& clientId();

  int statusCode();

  const QString& description();

  int eventRetVal();
  void setEventRetVal(int iRetVal);
};

// To handle, subclass BLEServer and override this emitter function.
virtual int fireConnected(BLEServerConnectedEventParams *e) {...}
// Or, connect one or more slots to this signal.
void connected(BLEServerConnectedEventParams *e);

Remarks

The underlying Bluetooth APIs do not notify the class when a remote device forms a low-level BLE connection to it. Instead, this event fires the first time a client interacts with one of your characteristics, by reading it (ReadRequested), writing it (WriteRequested), or subscribing to it (SubscriptionChanged).

ClientId is a platform-specific string that identifies the client, and is also provided as a parameter to the events above, as well as SessionStatusChanged and Disconnected, so that you can associate requests with a particular client.

StatusCode is always 0 and Description is always "OK", since a connection has, by definition, already been established by the time this event can fire.

Disconnected Event (BLEServer Class)

Fired when a connected client disconnects.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireDisconnected(BLEServerDisconnectedEventParams *e);

typedef struct {
  const char* ClientId;
  int StatusCode;
  const char* Description;
  int reserved;
} BLEServerDisconnectedEventParams;


Unicode (Windows)
virtual INT FireDisconnected(BLEServerDisconnectedEventParams *e);

typedef struct {
  LPCWSTR ClientId;
  INT StatusCode;
  LPCWSTR Description;
  INT reserved;
} BLEServerDisconnectedEventParams;

#define EID_BLESERVER_DISCONNECTED 3

virtual INT IPWORKSBLE_CALL FireDisconnected(char* &lpszClientId, int &iStatusCode, char* &lpszDescription);

class BLEServerDisconnectedEventParams {
public:
  const QString& clientId();

  int statusCode();

  const QString& description();

  int eventRetVal();
  void setEventRetVal(int iRetVal);
};

// To handle, subclass BLEServer and override this emitter function.
virtual int fireDisconnected(BLEServerDisconnectedEventParams *e) {...}
// Or, connect one or more slots to this signal.
void disconnected(BLEServerDisconnectedEventParams *e);

Remarks

This event fires when the GATT session for a previously-connected client (see Connected) is closed; refer to SessionStatusChanged for more information about session state changes.

ClientId identifies which client disconnected. StatusCode is always 0 and Description is always "OK".

If the disconnecting client had any active characteristic subscriptions, the SubscriptionChanged event will fire separately to reflect their removal.

Error Event (BLEServer Class)

Fired when information is available about errors during data delivery.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireError(BLEServerErrorEventParams *e);

typedef struct {
  int ErrorCode;
  const char* Description;
  int reserved;
} BLEServerErrorEventParams;


Unicode (Windows)
virtual INT FireError(BLEServerErrorEventParams *e);

typedef struct {
  INT ErrorCode;
  LPCWSTR Description;
  INT reserved;
} BLEServerErrorEventParams;

#define EID_BLESERVER_ERROR 4

virtual INT IPWORKSBLE_CALL FireError(int &iErrorCode, char* &lpszDescription);

class BLEServerErrorEventParams {
public:
  int errorCode();

  const QString& description();

  int eventRetVal();
  void setEventRetVal(int iRetVal);
};

// To handle, subclass BLEServer and override this emitter function.
virtual int fireError(BLEServerErrorEventParams *e) {...}
// Or, connect one or more slots to this signal.
void error(BLEServerErrorEventParams *e);

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the class fails with an error.

The ErrorCode parameter contains an error code, and the Description parameter contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

Log Event (BLEServer Class)

Fires once for each log message.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireLog(BLEServerLogEventParams *e);

typedef struct {
  int LogLevel;
  const char* Message;
  const char* LogType;
  int reserved;
} BLEServerLogEventParams;


Unicode (Windows)
virtual INT FireLog(BLEServerLogEventParams *e);

typedef struct {
  INT LogLevel;
  LPCWSTR Message;
  LPCWSTR LogType;
  INT reserved;
} BLEServerLogEventParams;

#define EID_BLESERVER_LOG 5

virtual INT IPWORKSBLE_CALL FireLog(int &iLogLevel, char* &lpszMessage, char* &lpszLogType);

class BLEServerLogEventParams {
public:
  int logLevel();

  const QString& message();

  const QString& logType();

  int eventRetVal();
  void setEventRetVal(int iRetVal);
};

// To handle, subclass BLEServer and override this emitter function.
virtual int fireLog(BLEServerLogEventParams *e) {...}
// Or, connect one or more slots to this signal.
void log(BLEServerLogEventParams *e);

Remarks

This events fires once for each log message generated by the class. The verbosity is controlled by the LogLevel setting.

LogLevel indicates the level of the Message. Possible values are:

The default log level, Info, provides information when most BLE operations begin and end, and should be sufficient to get a good idea of what the class is doing at a high level.

The Verbose log level adds a few extra operation timing messages, and adds more detail to some messages logged at the Info level.

The Debug log level causes the class to output as much information as possible about what it is doing at all times. All BLE communications, even those which are typically abstracted away by the API, are logged in full detail. Typically the additional information added by this log level is not helpful to the end user, and would only be necessary to capture if you wish to report an issue to the support team.

LogType identifies the type of log entry. Possible values are:

• Connection: Messages relating to connecting, disconnecting, and connection failures.
• Read: Messages relating to reading values from the remote device.
• Write: Messages relating to writing values to the remote device.
• Subscriptions: Messages relating to subscribing to and unsubscribing from characteristics.
• Info, Verbose, and Debug: Miscellaneous messages fired at the applicable log level concerning internal class operations.

ReadRequested Event (BLEServer Class)

Fired when a client requests to read a characteristic's value.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireReadRequested(BLEServerReadRequestedEventParams *e);

typedef struct {
  const char* ClientId;
  const char* ServiceId;
  const char* CharacteristicId;
  char* ResponseValue;
  int Accept;
  int reserved;
} BLEServerReadRequestedEventParams;


Unicode (Windows)
virtual INT FireReadRequested(BLEServerReadRequestedEventParams *e);

typedef struct {
  LPCWSTR ClientId;
  LPCWSTR ServiceId;
  LPCWSTR CharacteristicId;
  LPWSTR ResponseValue;
  BOOL Accept;
  INT reserved;
} BLEServerReadRequestedEventParams;

#define EID_BLESERVER_READREQUESTED 6

virtual INT IPWORKSBLE_CALL FireReadRequested(char* &lpszClientId, char* &lpszServiceId, char* &lpszCharacteristicId, char* &lpszResponseValue, int &bAccept);

class BLEServerReadRequestedEventParams {
public:
  const QString& clientId();

  const QString& serviceId();

  const QString& characteristicId();

  const QString& responseValue();
  void setResponseValue(const QString& qsResponseValue);

  bool accept();
  void setAccept(bool bAccept);

  int eventRetVal();
  void setEventRetVal(int iRetVal);
};

// To handle, subclass BLEServer and override this emitter function.
virtual int fireReadRequested(BLEServerReadRequestedEventParams *e) {...}
// Or, connect one or more slots to this signal.
void readRequested(BLEServerReadRequestedEventParams *e);

Remarks

This event fires when a connected client sends a request to read the current value of a characteristic that was added (via AddCharacteristic) with the Read flag set.

ClientId identifies the requesting client, and ServiceId and CharacteristicId identify the characteristic being read.

To answer the request, set ResponseValue to a hex-encoded string representing the bytes to return to the client, and leave Accept set to its default value of True. If you do not set ResponseValue, an empty value is returned. To reject the request instead (for example, if the value isn't currently available), set Accept to False.

bleserver1.OnReadRequested += (s, e) => { if (e.CharacteristicId.Equals("00002A19-0000-1000-8000-00805F9B34FB", StringComparison.OrdinalIgnoreCase)) { // Battery Level characteristic: respond with 90%, encoded as a single hex byte. e.ResponseValue = "5A"; } else { e.Accept = false; } };

SessionStatusChanged Event (BLEServer Class)

Fired when a connected client's GATT session status changes.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireSessionStatusChanged(BLEServerSessionStatusChangedEventParams *e);

typedef struct {
  const char* ClientId;
  int Status;
  int Error;
  int reserved;
} BLEServerSessionStatusChangedEventParams;


Unicode (Windows)
virtual INT FireSessionStatusChanged(BLEServerSessionStatusChangedEventParams *e);

typedef struct {
  LPCWSTR ClientId;
  INT Status;
  INT Error;
  INT reserved;
} BLEServerSessionStatusChangedEventParams;

#define EID_BLESERVER_SESSIONSTATUSCHANGED 7

virtual INT IPWORKSBLE_CALL FireSessionStatusChanged(char* &lpszClientId, int &iStatus, int &iError);

class BLEServerSessionStatusChangedEventParams {
public:
  const QString& clientId();

  int status();

  int error();

  int eventRetVal();
  void setEventRetVal(int iRetVal);
};

// To handle, subclass BLEServer and override this emitter function.
virtual int fireSessionStatusChanged(BLEServerSessionStatusChangedEventParams *e) {...}
// Or, connect one or more slots to this signal.
void sessionStatusChanged(BLEServerSessionStatusChangedEventParams *e);

Remarks

This event fires whenever the underlying GATT session for a connected client (see Connected) becomes active or is closed. It may fire more than once for the same client over the lifetime of a connection, for instance if the client temporarily goes out of range.

ClientId identifies the client. Status indicates whether the session is now active or closed (the exact numeric values used are platform-dependent). Error holds the underlying Bluetooth-stack error code associated with the change, or 0 if there isn't one.

When Status indicates that a client's session has closed, the Disconnected event fires immediately afterward for the same client.

SubscriptionChanged Event (BLEServer Class)

Fired when a characteristic gains or loses a subscribed client.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireSubscriptionChanged(BLEServerSubscriptionChangedEventParams *e);

typedef struct {
  const char* ServiceId;
  const char* CharacteristicId;
  int IsSubscribed;
  int reserved;
} BLEServerSubscriptionChangedEventParams;


Unicode (Windows)
virtual INT FireSubscriptionChanged(BLEServerSubscriptionChangedEventParams *e);

typedef struct {
  LPCWSTR ServiceId;
  LPCWSTR CharacteristicId;
  BOOL IsSubscribed;
  INT reserved;
} BLEServerSubscriptionChangedEventParams;

#define EID_BLESERVER_SUBSCRIPTIONCHANGED 8

virtual INT IPWORKSBLE_CALL FireSubscriptionChanged(char* &lpszServiceId, char* &lpszCharacteristicId, int &bIsSubscribed);

class BLEServerSubscriptionChangedEventParams {
public:
  const QString& serviceId();

  const QString& characteristicId();

  bool isSubscribed();

  int eventRetVal();
  void setEventRetVal(int iRetVal);
};

// To handle, subclass BLEServer and override this emitter function.
virtual int fireSubscriptionChanged(BLEServerSubscriptionChangedEventParams *e) {...}
// Or, connect one or more slots to this signal.
void subscriptionChanged(BLEServerSubscriptionChangedEventParams *e);

Remarks

This event fires when a client subscribes to, or unsubscribes from, notifications or indications on a characteristic that was added (via AddCharacteristic) with the Notify or Indicate flag set.

ServiceId and CharacteristicId identify the characteristic. IsSubscribed reflects the characteristic's overall subscription state: True if it now has one or more subscribed clients, or False if it has none. This event does not indicate which specific client subscribed or unsubscribed, nor how many clients are currently subscribed.

To push a new value to any subscribed clients, use UpdateValue.

WriteRequested Event (BLEServer Class)

Fired when a client requests to write a characteristic's value.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireWriteRequested(BLEServerWriteRequestedEventParams *e);

typedef struct {
  const char* ClientId;
  const char* ServiceId;
  const char* CharacteristicId;
  const char* Value;
  int lenValue;
  int WithResponse;
  int Accept;
  int reserved;
} BLEServerWriteRequestedEventParams;


Unicode (Windows)
virtual INT FireWriteRequested(BLEServerWriteRequestedEventParams *e);

typedef struct {
  LPCWSTR ClientId;
  LPCWSTR ServiceId;
  LPCWSTR CharacteristicId;
  LPCSTR Value;
  INT lenValue;
  BOOL WithResponse;
  BOOL Accept;
  INT reserved;
} BLEServerWriteRequestedEventParams;

#define EID_BLESERVER_WRITEREQUESTED 9

virtual INT IPWORKSBLE_CALL FireWriteRequested(char* &lpszClientId, char* &lpszServiceId, char* &lpszCharacteristicId, char* &lpValue, INT &lenValue, int &bWithResponse, int &bAccept);

class BLEServerWriteRequestedEventParams {
public:
  const QString& clientId();

  const QString& serviceId();

  const QString& characteristicId();

  const QByteArray& value();

  bool withResponse();

  bool accept();
  void setAccept(bool bAccept);

  int eventRetVal();
  void setEventRetVal(int iRetVal);
};

// To handle, subclass BLEServer and override this emitter function.
virtual int fireWriteRequested(BLEServerWriteRequestedEventParams *e) {...}
// Or, connect one or more slots to this signal.
void writeRequested(BLEServerWriteRequestedEventParams *e);

Remarks

This event fires when a connected client sends a request to write a new value to a characteristic that was added (via AddCharacteristic) with the Write or WriteWithoutResponse flag set.

ClientId identifies the requesting client, and ServiceId and CharacteristicId identify the characteristic being written to. Value holds the hex-encoded string of bytes the client wants to write. WithResponse is True if the client is expecting an acknowledgement (a "Write"), or False if it is not (a "Write Without Response").

If WithResponse is True, the response will use Accept to indicate if the request was accepted or rejected.

bleserver1.OnWriteRequested += (s, e) => { Console.WriteLine("Client " + e.ClientId + " wrote: " + e.Value); };

ServerCharacteristic Type

A GATT characteristic added to a BLE server.

Syntax

IPWorksBLEServerCharacteristic (declared in ipworksble.h)

Remarks

This type represents a GATT characteristic added to a BLE server.

• CanSubscribe
• Flags
• Id
• ServiceId
• Uuid

Fields

Constructors

ServerCharacteristic()
            

ServerService Type

A GATT service added to a BLE server.

Syntax

IPWorksBLEServerService (declared in ipworksble.h)

Remarks

This type represents a GATT service added to a BLE server.

• InstanceId
• Uuid

Fields

Constructors

ServerService()
            

IPWorksBLEList Type

Syntax

IPWorksBLEList<T> (declared in ipworksble.h)

Remarks

IPWorksBLEList is a generic class that is used to hold a collection of objects of type T, where T is one of the custom types supported by the BLEServer class.

int GetCount() {}

int SetCount(int count) {}

T* Get(int index) {}

T* Set(int index, T* value) {}

Config Settings (BLEServer Class)

BLEServer Config Settings

Base Config Settings

Trappable Errors (BLEServer Class)

Error Handling (C++)

Call the GetLastErrorCode() method to obtain the last called method's result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. Known error codes are listed below. If an error occurs, the GetLastError() method can be called to retrieve the associated error message.

BLEServer Errors