LBLEClient
This class allows users to create connections to remote peripheral devices.
To access device attributes, create LBLEClient object and call LBLEClient::connect to connect to the device in address:
Upon successful connection, connected() returns true.
The user can then query if certain GATT services exist on the remote device with getServiceCount(), getServiceUuid() and hasService(uuid).
Once the user confirmed that a service is available, the user may use APIs to read or write characteristics.
There are 2 sets of APIs:
Read or write characteristics based on their UUIDs. This is convenient if you already knew the UUID of the desired characteristics. However, there are many cases that the same UUID may appear on different services on the same BLE device. In these cases, you may end up read or write the characteristics that is not intended.
Read or write characteristics based on service index, and the index of the characteristics in the service, queried by
getCharacteristicCount. This set of API allows you to specify a characteristic in a specific service, thus this covers a more general case. However, you need to usegetCharacteristicCountandgetCharacteristicUuidto ensure the index of the characteristics you want to read or write.
Note that there is no extra "type" checking, so it is up to the user to make sure the value types are matched between read/write APIs and the remote device.
Constructors
LBLEClient
Creates a LBLEClient instance that can be used to connect to peripheral devices.
Syntax
Parameters
none
Returns
LBLEClient instance
Connection Methods
connect()
connected()
disconnect()
Start connecting to a remote peripheral device.
You can use LBLECentral singleton object to scan nearby devices and get their addresses.
Call connected() to check if the connection has been successfully established.
Note: this function also implicitly enumerates all the services and characteristics on the remote device, so it may take a while for this function to return.
Syntax
Parameters
none
Returns
true if the connection attempt starts successfully. Note that this does not mean the connection has been established.
false if fail to start connection.
Service Methods
hasService()
getServiceCount()
getServiceName()
getServiceUuid()
getCharacteristicCount()
Check if a service, identified with an UUID, is available on the remote connected device.
Syntax
Parameters
serviceUUID
128-bit or 16-bit UUID to identify the service.
Returns
true if the service is available on the remote device; false otherwise.
Characteristic Methods
getCharacteristicUuid()
readCharacteristicString()
readCharacteristicInt()
writeCharacteristicFloat()
writeCharacteristicString()
writeCharacteristicInt()
writeCharacteristicFloat()
Get the UUID of a characteristic in the service by its index
Syntax
Parameters
characteristicIndex
ranges from 0 to (getCharacteristicCount(serviceIndex) - 1).
Returns
Number of characteristics in the service.
Hepler API that write a characteristic on the remote device as a string.
Syntax
Parameters
string_to_write
The string value to write.
serviceIndex
ranges from 0 to (getServiceCount() - 1).
characteristicIndex
ranges from 0 to (getCharacteristicCount(serviceIndex) - 1).
Returns
>0 if written successfully.
0 if failed to write.
Last updated