Datasheet

Page 61 of 161
nRF8001 Product Specification
Revision 1.2
20.4 Transmit service pipes
Transmit pipes enable the transfer of application data to a peer device. A transmit pipe is associated with a
Characteristic declaration and a Characteristic Property defined in the service pipe configuration.
When acknowledgment is enabled, a transmit is acknowledged by the peer device. A
DataAckEvent is
generated by nRF8001 upon receiving the acknowledgment.
Table 26.
lists the available transmit pipe configurations and their functional description.
Table 26.Transmit pipe feature combinations
20.4.1 Opening a transmit pipe
Transmit pipes and transmit pipes with acknowledge on the local GATT server require opening prior to use.
Opening is initiated by the peer device. To open and close the pipes, the peer device writes to the Client
Configuration Characteristic Descriptor. For a Transmit Pipe, the peer device sets the Notification bit to
open. For a Transmit Pipe with acknowledge, the peer device uses the Indication bit to open and close it,
see table 3.11 in the
Bluetooth Core specification v4.0, Vol. 3, Part G, section 3.3.3. Once opened by the
peer, the pipe(s) will be listed in the OpenPipes bitmap returned by the
PipesStatusEvent.
Figure 27. on page 62
shows the sequence of events required to open local transmit pipes and local
transmit pipes with acknowledge.
Characteristic
location
Transmit pipe
feature
Functional description
Characteristic
Property
1
1. Bluetooth Core specification v4.0, Vol. 3, Part G, Chapter 4.2
Ack Request
Local No No · Update Server and notify Client (Peer
device). Notification contains the new
Charateristics Value.
Notify
Local Yes No · Update Server and send an indication of the
update to the Client (Peer device).
· Peer device acknowledges a successful
reception of the indication.
· nRF8001 generates
DataAckEvent
Indicate
Remote No No · Transmit data to Server (Peer device).
· Peer device does not acknowledge data
reception.
2
2. Data sent on a remote pipe with acknowledgment followed by data sent on a remote pipe with no
acknowledgment may lead to the loss of the DataAckEvent generated for the remote pipe with
acknowledgment.
Write without
Response
Remote Yes No · Transmit data to Server (Peer device).
· Peer device acknowledges a successful
data reception.
· nRF8001 generates
DataAckEvent.
2.
Write
Local No No · Broadcast the data using advertising
packets. This may be sent on un-
connectable and connectable
advertisement packets.
n/a