BLERemoteCharacteristic Class
BLERemoteCharacteristic Class
Description
A class used for managing BLE GATT characteristics on connected remote devices.
Syntax
class BLERemoteCharacteristic
Members
| Public Constructors |
| No public constructor is available for this class. You can get a pointer to an instance of this class using BLERemoteService::getCharacteristic(). |
| Public Methods | |
| BLERemoteCharacteristic::getDescriptor | Get a descriptor with the specified UUID on the remote device. |
| BLERemoteCharacteristic::getUUID | Get the characteristic UUID. |
| BLERemoteCharacteristic::setBufferLen | Set the size of the internal data buffer. |
| BLERemoteCharacteristic::getBufferLen | Get the current size of the internal data buffer. |
| BLERemoteCharacteristic::canRead | Determine if characteristic has read property enabled. |
| BLERemoteCharacteristic::canWrite | Determine if characteristic has write property enabled. |
| BLERemoteCharacteristic::canNotify | Determine if characteristic has notify property enabled. |
| BLERemoteCharacteristic::canIndicate | Determine if characteristic has indicate property enabled. |
| BLERemoteCharacteristic::getProperties | Get the characteristic properties. |
| BLERemoteCharacteristic::readString | Read the characteristic data buffer as a String object. |
| BLERemoteCharacteristic::readData8 | Read the characteristic data buffer as an unsigned 8-bit integer. |
| BLERemoteCharacteristic::readData16 | Read the characteristic data buffer as an unsigned 16-bit integer. |
| BLERemoteCharacteristic::readData32 | Read the characteristic data buffer as an unsigned 32-bit integer. |
| BLERemoteCharacteristic::writeString | Write data to the characteristic as a String object or character array. |
| BLERemoteCharacteristic::writeData8 | Write data to the characteristic as an unsigned 8-bit integer. |
| BLERemoteCharacteristic::writeData16 | Write data to the characteristic as an unsigned 16-bit integer. |
| BLERemoteCharacteristic::writeData32 | Write data to the characteristic as an unsigned 16-bit integer. |
| BLERemoteCharacteristic::setData | Write data to the remote device characteristic. |
| BLERemoteCharacteristic::getData | Get the characteristic data from the remote device and read the data in the buffer. |
| BLERemoteCharacteristic::enableNotifyIndicate | Enable notification or indication for the characteristic. |
| BLERemoteCharacteristic::disableNotifyIndicate | Disable notification and indication for the characteristic. |
| BLERemoteCharacteristic::setNotifyCallback | Set a user function as a notification callback. |
BLERemoteCharacteristic::getDescriptor
Description
Get a descriptor with the specified UUID on the remote device.
Syntax
BLERemoteDescriptor* getDescriptor(const char* uuid);
BLERemoteDescriptor* getDescriptor(BLEUUID uuid);
Parameters
uuid: the desired descriptor UUID, expressed as a character array or a BLEUUID object.
Returns
This function returns the found descriptor as a BLERemoteDescriptor object pointer, otherwise nullptr is returned if a descriptor with the UUID is not found.
Example Code
NA
Notes and Warnings
“BLERemoteCharacteristic.h” must be included to use the class function.
BLERemoteCharacteristic::getUUID
Description
Get the characteristic UUID.
Syntax
BLEUUID getUUID(void);
Parameters
NA
Returns
The function returns the characteristic UUID as a BLEUUID class object.
Example Code
NA
Notes and Warnings
“BLERemoteCharacteristic.h” must be included to use the class function.
BLERemoteCharacteristic::setBufferLen
Description
Set the size of the internal data buffer of the characteristic.
Syntax
void setBufferLen(uint16_t max_len);
Parameters
max_len: the size in bytes to resize the internal buffer to.
Returns
NA
Example Code
Example: BLEUartClient
(https://github.com/ambiot/ambd_arduino/blob/dev/Arduino_package/hardware/libraries/BLE/examples/BLEUartClient/BLEUartClient.ino)
Notes and Warnings
Characteristic data buffer has a default size of 20 bytes and can be increased up to 230 bytes. “BLERemoteCharacteristic.h” must be included to use the class function.
BLERemoteCharacteristic::getBufferLen
Description
Get the current size of the characteristic internal buffer.
Syntax
uint16_t getBufferLen(void);
Parameters
NA
Returns
This function returns the current internal buffer size that is set.
Example Code
NA
Notes and Warnings
“BLERemoteCharacteristic.h” must be included to use the class function.
BLERemoteCharacteristic::canRead
Description
Determine if characteristic has read property enabled.
Syntax
bool canRead(void);
Parameters
NA
Returns
This function returns TRUE if the read property for the characteristic is enabled.
Example Code
NA
Notes and Warnings
“BLERemoteCharacteristic.h” must be included to use the class function.
BLERemoteCharacteristic::canWrite
Description
Determine if characteristic has write property enabled.
Syntax
bool canWrite(void);
Parameters
NA
Returns
This function returns TRUE if the write property or the write no response property for the characteristic is enabled.
Example Code
NA
Notes and Warnings
“BLERemoteCharacteristic.h” must be included to use the class function.
BLERemoteCharacteristic::canNotify
Description
Determine if characteristic has notify property enabled.
Syntax
bool canNotify(void);
Parameters
NA
Returns
The function returns TRUE if the notify property for the characteristic is enabled.
Example Code
NA
Notes and Warnings
“BLERemoteCharacteristic.h” must be included to use the class function.
BLERemoteCharacteristic::canIndicate
Description
Determine if characteristic has indicate property enabled.
Syntax
bool canIndicate(void);
Parameters
NA
Returns
The function returns TRUE if the indicate property for the characteristic is enabled.
Example Code
NA
Notes and Warnings
“BLERemoteCharacteristic.h” must be included to use the class function.
BLERemoteCharacteristic::getProperties
Description
Get the characteristic properties.
Syntax
uint16_t getProperties(void);
Parameters
NA
Returns
The function returns the characteristic properties.
Example Code
NA
Notes and Warnings
“BLERemoteCharacteristic.h” must be included to use the class function.
BLERemoteCharacteristic::readString
Description
Request for characteristic data from the remote device and read the data in the buffer, expressed as a String class object.
Syntax
String readString(void);
Parameters
NA
Returns
The function returns the data in the characteristic data buffer expressed as a String class object.
Example Code
Example: BLEUartClient
(https://github.com/ambiot/ambd_arduino/blob/dev/Arduino_package/hardware/libraries/BLE/examples/BLEUartClient/BLEUartClient.ino)
Notes and Warnings
“BLERemoteCharacteristic.h” must be included to use the class function.
BLERemoteCharacteristic::readData8
Description
Request for characteristic data from the remote device and read the data in the buffer, expressed as an unsigned 8-bit integer.
Syntax
uint8_t readData8(void);
Parameters
NA
Returns
This function returns the data in the characteristic data buffer expressed as a uint8_t value.
Example Code
Example: BLEBatteryClient
(https://github.com/ambiot/ambd_arduino/blob/dev/Arduino_package/hardware/libraries/BLE/examples/BLEBatteryClient/BLEBatteryClient.ino)
Notes and Warnings
“BLERemoteCharacteristic.h” must be included to use the class function.
BLERemoteCharacteristic::readData16
Description
Request for characteristic data from the remote device and read the data in the buffer, expressed as an unsigned 16-bit integer.
Syntax
uint16_t readData16(void);
Parameters
NA
Returns
This function returns the data in the characteristic data buffer expressed as a uint16_t value.
Example Code
NA
Notes and Warnings
“BLERemoteCharacteristic.h” must be included to use the class function.
BLERemoteCharacteristic::readData32
Description
Request for characteristic data from the remote device and read the data in the buffer, expressed as an unsigned 32-bit integer.
Syntax
uint32_t readData32(void);
Parameters
NA
Returns
This function returns the data in the characteristic data buffer expressed as a uint32_t value.
Example Code
NA
Notes and Warnings
“BLERemoteCharacteristic.h” must be included to use the class function.
BLERemoteCharacteristic::writeString
Description
Write data to the remote device characteristic as a String object or character array.
Syntax
bool writeString(String str);
bool writeString(const char* str);
Parameters
str: the data to write to the remote characteristic, expressed as a String class object or a char array.
Returns
This function returns TRUE if writing data to the remote device characteristic is successful.
Example Code
NA
Notes and Warnings
“BLERemoteCharacteristic.h” must be included to use the class function.
BLERemoteCharacteristic::writeData8
Description
Write data to the remote device characteristic as an unsigned 8-bit integer.
Syntax
bool writeData8(uint8_t num);
Parameters
num: the data to write to the characteristic buffer expressed as an unsigned 8-bit integer.
Returns
This function returns TRUE if writing data to the remote device characteristic is successful.
Example Code
NA
Notes and Warnings
“BLERemoteCharacteristic.h” must be included to use the class function.
BLERemoteCharacteristic::writeData16
Description
Write data to the remote device characteristic as an unsigned 16-bit integer.
Syntax
bool writeData16(uint16_t num);
Parameters
num: the data to write to the characteristic buffer expressed as an unsigned 16-bit integer.
Returns
This function returns TRUE if writing data to the remote device characteristic is successful.
Example Code
NA
Notes and Warnings
“BLERemoteCharacteristic.h” must be included to use the class function.
BLERemoteCharacteristic::writeData32
Description
Write data to the remote device characteristic as a 32-bit integer.
Syntax
bool writeData32(uint32_t num);
bool writeData32(int num);
Parameters
num: the data to write to the characteristic buffer expressed as a 32-bit integer.
Returns
This function returns TRUE if writing data to the remote device characteristic is successful.
Example Code
NA
Notes and Warnings
“BLERemoteCharacteristic.h” must be included to use the class function.
BLERemoteCharacteristic::setData
Description
Write data to the remote device characteristic.
Syntax
bool setData(uint8_t* data, uint16_t datalen);
Parameters
data: pointer to byte array containing desired data.
datalen: number of bytes of data to write.
Returns
This function returns TRUE if writing data to the remote device characteristic is successful.
Example Code
NA
Notes and Warnings
“BLERemoteCharacteristic.h” must be included to use the class function.
BLERemoteCharacteristic::getData
Description
Get the characteristic data from the remote device and read the data in the buffer.
Syntax
uint16_t getData (uint8_t* data, uint16_t datalen);
Parameters
data: pointer to byte array to save data read from buffer.
datalen: number of bytes of data to read.
Returns
This function returns the number of bytes read.
Example Code
NA
Notes and Warnings
If the data buffer contains less data than requested, it will only read the available number of bytes of data. “BLERemoteCharacteristic.h” must be included to use the class function.
BLERemoteCharacteristic::enableNotifyIndicate
Description
Enable the remote device to send notifications or indications for the characteristic.
Syntax
void enableNotifyIndicate(bool notify);
Parameters
notify: TRUE to enable notifications, FALSE to enable indications. Default value: “1” – True.
Returns
NA
Example Code
Example: BLEUartClient
(https://github.com/ambiot/ambd_arduino/blob/dev/Arduino_package/hardware/libraries/BLE/examples/BLEUartClient/BLEUartClient.ino)
Notes and Warnings
“BLERemoteCharacteristic.h” must be included to use the class function.
BLERemoteCharacteristic::disableNotifyIndicate
Description
Disable receiving notifications and indications for the characteristic from the remote device.
Syntax
void disableNotifyIndicate(void);
Parameters
NA
Returns
NA
Example Code
NA
Notes and Warnings
“BLERemoteCharacteristic.h” must be included to use the class function.
BLERemoteCharacteristic::setNotifyCallback
Description
Set a user function to be called when the characteristic receives a notification from the remote device.
Syntax
void setNotifyCallback(void (*fCallback) (BLERemoteCharacteristic* chr, uint8_t* data, uint16_t length));
Parameters
fCallback: A user callback function that returns void and takes three arguments.
chr: pointer to BLERemoteCharacteristic object associated with notification.
data: pointer to byte array containing notification data.
length: number of bytes of notification data in array.
Returns
NA
Example Code
Example: BLEUartClient
(https://github.com/ambiot/ambd_arduino/blob/dev/Arduino_package/hardware/libraries/BLE/examples/BLEUartClient/BLEUartClient.ino)
Notes and Warnings
“BLERemoteCharacteristic.h” must be included to use the class function.
