Data Member 

Description 

attr_handle 

The function represents the attribute handle. 

bd 

This function represents the Bluetooth 4.0 address. 

offset 

This function offsets into the data buffer, in bytes. For example, if the characteristic is 20 bytes long and the central device requests a 10 bytes offset, then the service should call ackOk() with value buffer starting with buffer[10]. 

trans_id 

This function represents the transaction ID. 

Method 

Description 

ackFail 

You can call this method in onRead() and callback to respond with failed result to the read request. 

ackOK 

You can call this method in onRead() and callback to send the value of the attribute to central device.