nRF24LE1 Nordic VLSI, nRF24LE1 Datasheet - Page 23

• Manufacturer Part Number: nRF24LE1
• Manufacturer: Nordic VLSI

nRF24LE1 Preliminary Product Specification
acknowledgment packet (ACK packet) from the PRX. The PRX can attach user data to the ACK packet
enabling a bi-directional data link.
The automatic packet transaction handling works as follows:
In Enhanced ShockBurst™ it is possible to configure parameters such as the maximum number of retrans-
mits and the delay from one transmission to the next retransmission. All automatic handling is done without
the involvement of the MCU.
3.4.3
The format of the Enhanced ShockBurst™ packet is described in this section. The Enhanced Shock-
Burst™ packet contains a preamble field, address field, packet control field, payload field and a CRC field.
Figure 7.
3.4.3.1
The preamble is a bit sequence used to synchronize the receivers demodulator to the incoming bit stream.
The preamble is one byte long and is either 01010101 or 10101010. If the first bit in the address is 1 the
preamble is automatically set to 10101010 and if the first bit is 0 the preamble is automatically set to
01010101. This is done to ensure there are enough transitions in the preamble to stabilize the receiver.
3.4.3.2
This is the address for the receiver. An address ensures that the correct packet is detected by the receiver.
The address field can be configured to be 3, 4 or, 5 bytes long with the AW register.
Revision 1.1
1.
2.
3.
P re a m b le 1 b y te
Note: Addresses where the level shifts only one time (that is, 000FFFFFFF) can often be detected in
You begin the transaction by transmitting a data packet from the PTX to the PRX. Enhanced
If the packet is received by the PRX, Enhanced ShockBurst™ automatically assembles and
If the PTX does not receive the ACK packet immediately, Enhanced ShockBurst™ automatically
ShockBurst™ automatically sets the PTX in receive mode to wait for the ACK packet.
transmits an acknowledgment packet (ACK packet) to the PTX before returning to receive mode.
retransmits the original data packet after a programmable delay and sets the PTX in receive
mode to wait for the ACK packet.
shows the packet format with MSB to the left.
Enhanced Shockburst™ packet format
noise and can give a false detection, which may give a raised Packet-Error-Rate. Addresses
as a continuation of the preamble (hi-low toggling) raises the Packet-Error-Rate.
Preamble
Address
A d d re s s 3 -5 b y te
Figure 7. An Enhanced ShockBurst™ packet with payload (0-32 bytes)
P a c k e t C o n tro l F ie ld
23 of 191
9 b it
P a y lo a d 0 - 3 2 b y te
C R C 1 -2
b y te